1>9

*' S-- S' « !•'

V^'

c(^iz^i^ /L ^ A^^^^f^i^^

//^ (_ ^/-fi,/.

'■e4y' y/d'6^/

ANNUAL

OF

SCIENTIFIC DISCOVERY

R,

YEAR-BOOK OF FACTS IN SCIENCE AND ART

FOB

1866 AND 1867.

EXHIBITIKG THE

MOST IMPORTANT DISCOVERIES AND IMPROVEMENTS

IN

MECHANICS, USEFUL ARTS, NATURAL PHILOSOPHY, CHEMISTRY,

ASTRONOMY, GEOLOGY, ZOOLOGY, BOTANY, MINERALOGY,

METEOROLOGY, GEOGRAPHY, ANTIQUITIES, ETC.

TOGETHER WITH

NOTES ON THE PROGRESS OF SCIENCE DURING THE YEARS, 1865 AND 1866;

A LIST OF RECENT SCIENTIFIC PUBLICATIONS; OBITUARIES

OF EMINENT SCIENTIFIC MEN, ETC.

EDITED BY

SAMUEL KNEELAND, A.M., M.D.,

FELLOW OF THE AMERICAN ACADEMY OP ARTS AND SCIENCES, SECRETARY OF TUK
MASSACHUSETTS INSTITUTE OF TECHNOLOGY, ETC.

BOSTON:

g-otjijD a. isr d LiisrcoLisr,

69 WASHINGTON STREET.

KEW YORK: SHELDON AND COMPANY.

CINCINNATI: GEORGE S. BLANCHARD & CO.

LONDON: TRUBNER & CO.

1867.

Entered, according to Act of Congress, In the year 1807, by

GOULD AND LINCOLN,

In the Clerk's Office of the District Court for the District of Massachusetts.

ROCKWELL & BOLLINS,

PEIKTERi AND STEEEOTYPEES, BOSTON.

PEEFATOEY NOTE.

"Washington, D. C, February, 1867.
To THE Readers of th^ "Annttal op Scientific Discovery:"

Having been called to the supervision of a branch of the public
service, the duties of which are too engrossing and responsible to
allow of any diversion of attention or employment, the under-
signed is compelled to announce his withdi-awal (at least for the
present) from the editorial charge and management of the "An-
nual of Scientific Discovery."

He has, however, the satisfaction of knowing that his with-
drawal is not to affect the continued publication of the work ; and
that, under the guidance of the eminent scientific gentleman
whose name appears on the title-page of the present volume, the
sphere of usefulness of the "Annual of Scientific Discovery" is
certain to be not only maintained, but greatly enlarged.

With no little personal regret at being thus compelled to give
up a woi'k which for more than fifteen years has been followed as
a labor of love,

I am, most respectfully,

DAVID A. WELLS,
iii U. S. Commissioner of Revenue.

^c>/q

NOTES BY THE EDITOR,

ON TUB

PROGRESS OF SCIENCE FOR THE YEARS 1865 AND 1866.

The years 1865 and 18G6 have been uncommonly prolific in sci-
entific discovei-y, in almost every department of knowledge. This
has been mainly due to the activity of Associations for promoting
the progress of special branches of knowledge, which not only
furnish important and varied contributions to science, but consti-
tute impartial triburtals for the determination of the value of indi-
vidual reseax"ches. Among these, the Royal Society and British
Association in England, the Academy of Sciences of France, and
the American Association (this year successfully revived after an
interval of five years) and the Natioffal Academy in this country,
stand prominent.

Taking the departments of science in the order adopted in this
work, the mechanic and useful arts first claim attention. The
successful laying ,oi the new Atlantic telegraph cable, and the
picking up and utilizing the old cable, are the greatest engineer-
ing achievements of the year 1866, and continue to excite the in-
terest of the scientific world. The completion of the Chicago
tunnel under Lake Michigan will doubtless inaugurate a new era
in subterranean modes of communication ; and the success of the
third or centre-rail system over Mt. Cenis will probably ere long
do away with the tedious and expensive plans of boring through
mountain chains both in Europe and this country.

In marine and locomotive engineering the improvements are
chiefly in the direction of economy of fuel by modifications of fur-
naces and flues, and especially by the due supply of air for com-
plete combustion. Surface condensation increases in the estima-
tion of the best engineers, greatly increasing the economy of ma-
rine engines. The use of superheated steam is yet in its infancy,
IV

NOTES BY THE EDITOR. V

but it is to be hoped that theoretical fears on this subject will soon
be dissipated by successful experience. The use of petroleum as
a fuel for steam engines seems to be approaching practical appli-
cation.

The substitution of steel for iron in various parts of locomotives,
and for rails, has added gi-eatly to the permanence of the ma-
chinery, and diminished the wear and tear in a remarkable de-
gree. The extensive use of steel in ship-building, esijecially
since the Bessemer process has come into vogue, has contril)uted
much to the strength and safety of sea-going vessels, with dimin-
ished weight, and seems likely to restrict the composite system
of v/ood and iron construction to those navigating smooth waters.

The battle of the guns versus armoi'-jjlates is still waged with
great vigor, and the-victory just now appears to be on the side of
the steel projectiles and chilled shot of Maj. Palliser and others;
but this will only give rise to improved machinery, a better selec-
tion of material, and better processes of manufacture on the part
of the armor-plate makers.

The new gunpowder of Capt. Schultze, made from wood, by a
process similar to that of making gun-cotton, bids fair to rival the
old explosive for certain purposes. Nitroglycerine and gun-paper
have also been successfully introduced, the former for blasting,
and the latter for small arms.

In respect to light, heat, chemical affinity, electricity, and mag-
netism, universal attributes of matter in all its forms, it may be
considered as proved that all these forces are so invariably con-
nected inter se and with motion, as to be regarded as modifications
of each other, and as resolving themselves objectively into mo-'
tion, and subjectively into that something which produces or
resists motion, and which we call force.

Recent researches go to show that magnetism is cosmical, and
not merely terrestrial. One of the startling suggestions made by
Mayer, as a consequence resulting from the dynamical theory of
heat, is that, by the loss of the vis viva occasioned by friction of
the tidal waves, as well as by their forming a drag upon the
earth's rotary movement, the velocity of the earth's rotation must
be gradually diminishing, and that thus, unless some undiscovered
compensatory action exist, this rotation must ultimately cease, and
changes hardly calculable take place in the solar system. M. De-
launay and Mr. Airy consider that part of the acceleration of the
moon's mean motion, not at present accounted for by planetary
1*

TI NOTES BY THE EDITOR

disturbances, is due to the gradual retardation of the earth's
rotation.

According to Mr. Grove, in his Inaugural Address to the British
Association for 1866, from which we quote largely, there are some
objections, though not insuperable, against the theory of Mayer,
thivt the licat of the sun is caused by friction or percussion of me-
teorites falUng upon it ; but these cosmical bodies have not been
ascertained to impinge upon the sun in a definite direction from
their gradually lessening orbits. And M. Faye, who has recently
investigated the pi-oper motions of the sun-spots, has pointed out
many objections to this theory, and attril)utes them to some gen-
eral action arising from the internal mass of the sun.

Assuming the undulatory theory to be true, and that light
must lose something as light, in its progress from distant luminous
bodies, it becomes an interesting question what becomes of the
enormous force of light lost, and heat radiated into space, which
do not apparently return in the same forms. Force cannot be an-
nihilated; its modes of action in this case are only changed.
Tliis is one of the most interesting problems of celestial dynamics,
which we wait for some Newton to solve.

The doctrine of the correlation of forces is steadily gaining
ground. Many points of great practical importance are connected
with this subject, as whether we can produce heat by the expen-
diture of other forces than those locked ujj in our coal-beds and
forests ; whether we can absorb and store up fur future use, by
chemical or mechanical means, the rays of the sun now wasted
for human purposes in the desert and the tropics.

The researches of Prof. T3-ndall on radiant heat, and the dis-
coveries of Graham on the increased potential energy of atmos-
pheric air when passed through films of caoutchouc, it becoming
richer in oxygen by losing half its nitrogen, are interesting as
indications of means for storing up force. The magneto-electric
machine of Mr. Wilde, and the electrical machine of Mr. Holz,
show how mechanical may be advantageously converted into
electrical force. The greatest practical conversion of force is ex-
emplified in the fact that the chemical action of a little salt water
upon a few pieces of zinc, as shoTvna in the Atlantic cable, has
bound the two hemispheres together by electrical action.

The remarkable results of spectrum analysis, from the labors of
Kirchhoff, Bunsen, Huggins, and Miller, have thrown a flood of
light upon the structure of the heavenly bodies. These conclu-
sions wiU be found under the Head of " Celestial Chemistry."

ON THE PROGRESS OF SCIENCE. VII

The old theories of geological convulsions and cataclysms by
which the inequalities of the earth's surface and the many breaks
in the geological record were explained, are now supplanted by
the modern view of Lvell and others, which refers the chan^-es in
the past to causes similar to those now in operation. With this,
since the researches of Darwin, has become connected the ques-
tion, whether, in a geological formation unmistakably continu-
ous, the different characters of the fossils represent absolutely
permanent varieties, or may be explained by gradual modifying
changes. It is quite possible that many modifications of size and
form, regarded as permanent, and on which specific diff"erences
have been assumed, may be due to changes in the conditions of
existence. The opponents of Darwin's theory have a strong
point in the fact that, with the i^resent knowledge of fossil forms, the
physical breaks in the strata make it impossible to fairly trace the
order of succession of organisms ; but, notwithstanding the imper-
fection of the geological record, the belief widely pi-e vails among
geologists that the succession of species bears a definite relation
to the succession of strata.

Since Sir John Herschel, more than thirty years ago, proposed
to explain the climatal perturbations on the earth's surface, with
the attendant geological phenomena, by changes in the eccen-
tricity of the earth's orbit, cosmical studies have been more inti-
mately associated with geology. Mr. Croll has recently shown
reason to believe that the climate in the frigid and temperate
zones of the eai'th Avould depend on whether the winter of a given
region occurred when the earth at its period of greatest eccen-
tricity was in aphelion or perihelion — if the former, the annual
average of temperatare would be lower, — if the latter, it would
be higher than when the eccentricity of the eartli's orbit was less,
or approached more nearly to a circle — he calculates tlie differ-
ence in the amount of heat, in these two positions, as nineteen to
twenty-six. He thus explains the glacial, carboniferous or hot,
and the normal or temperate periods, which we observe in geo-
logical records; he estimates that it is certainly not less, and
pi-obably much moi-e, than one hundred thousand years since the
last glacial epoch.

The progress of physiology during the last two years has been
great, ijrincipally owing to microscopical and chemical investiga-
tions. The discovery of development by cells, evincing a simple,
uniform law, underlying and working out the very different forms

Vni NOTES BY TOE EDITOR

and structures of vegetable and animal life, marked a new era in
physiological science. Says Prof. Huxley, " Surely the knowl-
edge that the tough oak plank, the blade of grass, the lion's claw,
the contracting muscle, and the thinking brain, all emanate from
simple forms which, so far as we can tell, are perfectly alike, —
and further, that the entire plant or animal also emanates from a
single form or cell which is undistinguishable from the rudiments
of its several parts, is as full of interest, and as suggestive of high
thought as any one of the fragments of knowledge which man
has worked out for himself in the whole range of phj^sical science ;
and what better exercise can there be than teaching the operation
of tlie great law of uniformity ? "

Organic chemistry has accumulated a vast aiTay of facts which
its professors are bringing to bear upon some of the most impor-
tant questions in physiology, and their habits of investigation and
knowledge of the nature of the forces acting within the body have
made them umpires in many of the sanitary and even medical
questions of the day. Such is the rapid advance of the chemical
knowledge of common things, that physicians must be chemists to
that degree as to be able to answer questions arising regarding
the air, water, food, drink, and medicine which, by means of
forces that exist in them, act upon the forces within the human
body, and give rise to the phenomena of health and disease.
From the researches of Traube, Playfair, E. Smith, Fick and
Wislicenus, Frankland, and others, we know that the amount of
labor which a man has undergone in twenty-four hours may be
approximately arrived at by an examination of the chemical
changes which have taken place in his body ; " changed forms in
matter indicating the anterior exercise of dynamical force." All
will admit tliat muscular action is produced at the expense of
chemical changes, but until recentl}' it was generally believed
that muscular power is derived from the oxidation of albuminous
or nitrogenous substances ; but more recent researches, detailed
in the text, show that the latter is only an accompaniment and
not the cause of the former, and that muscular force is supplied
by the oxidation of carbon and hydrogen compounds. Messrs.
Fick and Wislicenus, from their experiments in ascending the
Faulhorn, state that " so far from the oxidation of albuminous
substances being the only source of muscular power, the sub-
stances by the burning of which force is generated in the muscles
are not the albuminous constituents of those tissues, but non-

ON THE PROGRESS OF SCIENCE. DC

nitrogenous substances, either fats or hydrates of carbon, and that
the burning of albumen is not in any way concerned in the pro-
duction of muscular power."

The theory of Darwin, that species are not rigidly limited, and
have not been created at various times comjilete and unchange-
able, but have been gradually and indefinitely varied, from exter-
nal circumstances, from natural efforts to accommodate them-
selves to surrounding changes, and from the necessity of yielding
to force in the struggle for existence, has continually gained
ground, and now numbers among its advocates many of the first
naturalists of Europe and this country. The opponents of this
theory have their strong jooints in accommodating definitions of a
species, the phenomena of hybridity, and the non-occurrence of
these changes before our eyes. If species were created as we
now see them, the more we subdivide them by extended obser-
vation the more we increase the number of the supposed crea-
tions ; and yet we have no well authenticated instance of a new
creation, and in no other opei'ations of nature such a want of con-
tinuity, such a perpetually recurring creative miracle. The ten-
dency seems to be to the belief that there are no such natural
divisions as species, genei'a, families, etc., but that they are merely
convenient terms for subdivisions, having a permanence which
may outlive many generations of man, and yet which are not ab-
solutely fixed. Such is the length of geological periods now
admitted, that the phenomena of hybridity may be legitimately
explained on the theory of the continuity of succession ; the infe-
cundit}'' may just as well be due to physical differences arising
from long-continued variation, as to an original organic constitu-
tion ; indeed, the acknowledged degrees of h3'bridity are best
explained on Darwin's theory. Darwin insists upon time for the
changes by natural selection ; and no one will pretend, at the pres-
ent day, to date back the earth's history only a few thousand years.
Geology teaches that hundreds of thousands of years do not limit
the period of the earth's existence as an abode for living organ-
isms. In the early days of geological science, the numerous gaps
in the record of fossil forms would have been a strong argument
against the theory of Darwin; certain species seemed to become
extinct and new ones to appear without connecting links ; but, as
page after page of this geological record has been discovered, tho
gaps become less numerous and less abrupt, and the intermediate
torms are gradually being added to form the continuous series.

X NOTES BY THE EDITOR

The more the gaps between species are filled up by the discovery
of inteiinediate varieties, the stronger becomes the argument for
transmutation, and the weaker that for successive creations; be-
cause the fonner view then becomes more and more consistent
with experience, and the latter more and more inconsistent with
it. The investigations of Mr. Bates on the butterflies of the Am-
azon region, of Mr. Wallace on those of the Malay Archipelago,
of Mr. I>. I). Walsh on the eficet of food in insects, — Sir John
Lubbock's diving hynionopLerous insect; the discovery of Eozoon
at a period inconceivably antecedent to the pre-supposed intx'o-
duction of life upon the globe ; the published opinions of De Can-
dollc and Hooker, in botany; the phases of resemblance to infe-
rior orders which the embryo goes through in its development ;
the metamorphosis of plants, and the occurrence of rudimentary
and useless organs, — all sui)ply strong evidence in favor of the
derivative hj'pothesis. The present more quiet and uniform rate
of pliysical changes would involve a greater degree of fixity in
living forms than in the earlier periods of rapid transition. It
must also be remembered that only a very small portion of the
extinct forms have been preserved as fossils; were the series
complete, the question would be solved, and, in the opinion of
many good judges, most likely in favor of the derivative hyjjoth-
esis. The opponents of continuity lay all stress upon the lost links
of the palaeontological chain, and none upon the few existing and
altogether exceptional ones ; and the worst of it is, that the
chance of filling up the missing links, from the operation of de-
structive causes, is very small.

The controversy of MM. Pasteur and Pouchet on spontaneous
generation had ended in the general belief that the latter was in
error, but more recent experiments of Mr. Child again opened the
question; the weight of opinion, however, continues to be against
the theory of spontaneous generation, or, if heterogeny obtains
at all, that it is confined to the most simple structures, such as
vibrios and bacteria, the more highly-developed and progressive
forms being generated by reproduction.

Meteoi'ites are now acknowledged to be cosmical bodies mov-
ing in the interplanetary spaces by gravitation around the sun,
and some perhaps around the planets, showing that the universe
has not the empty spaces formerly attributed to it, but is studded
with smaller planets between the larger and more visible masses.
Such as have fallen upon the earth give on analysis metals and

ON THE PEOGRESS OF SCIENCE. XI

oxides similar to those which belong to onr own planet. M. Dau-
bi'ee, before the French Academy, has given the chemical and
mineralogical chai'acters of meteorites, and finds that their sim-
ilariL}' to terrestrial rocks increases as we penetrate into the crust
of the earth, and that some of our deep-seated minerals, as olivine,
serpentine, etc., are almost identical with meteoric constituents.
When we consider that the exterior of the earth is oxidated to a
considerable extent, there is no cause for wonder that its deox-
idated interior should possess a higher specific gravity than the

Cl'USt.

The asteroids and planets now number ninety-two, and proba-
bly the next half century will demonstrate that the now seeming-
ly vacant interjilanetary spaces are occujiied by many others of
these bodies.

Our own satellite has been the subject of rigid scrutiny, yet the
question whether the moon possesses any atmosphere cannot be
regarded as solved ; if there be any, it must be exceedingly
small in quantity and highly attenuated. It is believed that there
is not oxygen enough in the moon to oxidate the metals of which
it is composed, and that the surface which we see is metallic, or
nearly so. M. Chacornac's recent observations lead him to the
belief that many of the lunar craters were the result of a single
explosion, which raised the surface as a bubble, and deposited the
dihris around the orifice of ei'uption. The lunar eruptions evi-
dently did not take j^lace at one period only, as in many parts one
crater is seen encroaching on and displacing others.

It is to be hoped that the achromatic telescope will ere long be
freed from its old and great defect, " the inaccuracy of definition,
arising from what was termed the irrationality of the spectrum, or
the incommensurate divisions of the spectra, formed by flint and
crown glass."

The improvements of Mr. Alvan Clark, of Cambridge, Mass.,
in the construction and local correction of lenses for the telescope,
for which the Rumford JNIedal has recently been awarded by the
American Academy, mark a new era in astronomical observation.
. Eecent discoveries in palseontology prove that man existed on
this earth at a j)eriod far anterior to that commonly assigned to
him. The chipped flints of the earliest races show that their con-
dition was not that of civilization ; to these rude implements suc-
ceeded more carefully shaped and polished stone weapons, then
bronze was used, and, the last, before the historic period, iron.

XII NOTES BY THE EDITOR.

Civilization, even to the extent of that of the Egyptians and the
Central Americans, must have been of very slow growth ; as in-
vention is said to march with a geometrical progression, the earli-
est steps nmst have been exceedingly slow.

Time is the great element, both in the development of vegeta-
ble and animal life, and also in the progress of man from
barbarism to civilization ; and this must be a primary idea in the
consideration of the theoiy of Darwin. In this relation we will
conclude by quoting from the Inaugural Address of Mr. Grove,
before alluded to. "The prejudices of education, and associa-
tions witli the past, are against this (Darwin's theory of the origin
of species by natural selection, etc.), as against all new views;
and while, on the one hand, a theory is not to be accepted be-
cause it is new and primd facie plausible, still, to this assembly, I
need not say that its running counter to existing opinions is not
necessarily a reason for its rejection ; the onus probandi should
rest on those who advance a new view, but the degree of proof
must differ with the nature of the subject. The fair question is.
Does the newly-projiosed view remove more difficulties, require
fewer assumptions, and present more consistency with observed
facts, than that which it seeks to supersede.^ If so, the philoso-
pher will adopt it, and the world will follow the f>hilosopher —
after many days." He is strongly in favor of the new theorj', dis-
believing in per saltiim or sudden creations, and maintains that
continuity is a law of nature, the true expression of tlie action of
Almighty Power, and that we should cease to look for special in-
terventions of the creative act — " we should endeavor from the
relics to evoke their history, and, when we find a gap, not try to
bridge it over by a miracle."

The readers of the "Annual of Scientific Discovery" will be
gi-atified to possess the fine Porti-ait of Hon. David A. Wells,
U. S. Commissioner of Revenue, and late editor of this work,
presented in the present volume.

THE

ANNUAL OF SCIENTIFIC DISCOVERY.

MECHANICS AND USEFUL ARTS.

ATLANTIC TELEGRAPH.

The greatest achievement, in a scientific point of view, which
has occuiTed during the present year, is the successful laying of
the Atlantic Telegraph Cable, from Valentla, on the coast of Ire-
land, 2,000 miles across the bed of the Atlantic Ocean, to Heart's
Content, Newfoundland, electrically uniting Europe and America.
This is not only a marked epoch in the progress of science, and a
triumph over physical obstacles deemed insurmountable, but it is
an event of great international interest, and an inestimable com-
mercial boon — reflecting honor alike upon the skill of the me-
chanic, the science of the physicist, the intelligence of the sea-
man, and the liberality of the merchant.

Foremost among the names of those who have contributed to
this successful result, is our countryman, Cyrus W. Field, who
for neai'ly thirteen years has labored, through good and evil re-
poi't, with indomitable energy, not resting till his cherished idea
had become a reality.

From his remarks on various occasions, and from scientific
journals of England and this country, the following account of
the Atlantic Telegraph is condensed by the Editor.

Ml". Field, at a banquet given in his honor at New York, Nov.
15, 1866, gave a brief history of this great undertaking, reported
in the "New York Times" of Nov. 16th, from which the fol-
lowing are extracts. Says Mr. Field : —

" It is nearly thirteen years since half a dozen gentlemen of
this city met at my house for four successive evenings, andaround
a table covered with maps and charts, and plans and estimates,
considered a project to extend a line of telegrajjh from Nova
Scotia to St. Johns, in Newfomidland, thence to be carried across
2 13

14 ANNUAL OF SCIENTIFIC DISCOVERT.

the ocean. It was easy to draw a line from one point to the
other — making no account of the forests and mountains and
swamps and rivers and gulfs, that Liy in our way. Not one; of
us liad ever seen the country, or liad any idea of the obstacles
to be overcome. "We thought we could build the line in a few
months. It took two years and a half. The arduous and costly
work was accomplished. A road was cut through 400 miles of
wilderness, and after two attempts in 1865 and 18.')0, a cable, pro-
cured in England, was laid across the Gulf of St. Lawrence.
Yet we never asked for help outside our own little circle. In-
deed, I fear we should not have got it if we had — for few had
any faith in our scheme. Every dollar came out of our own
pockets. Yet I am proud to say no man drew back. No man
proved a deserter ; those who came first into the work have stood
by it to the end. Of those six men, four are here to-night — Mr.
Peter Cooi^er, Closes Taylor, Marshall O. Roberts, and myself.
My brother Dudley is in Europe, and Mr. Chandler White died
in 18JG, and his place was supplied by Mr. Wilson G. Hunt, who
is also here. Mr. Robert W. Lowber was our Secretary. To
these gentlemen, as my first associates, it is but just that I should
pay my first acknowledgments.

"From this statement you perceive that in the beginning this
was wh(jlly an American enterprise. It was begun, and f(n' two
years and a half was carried t)n, solely by American capital. Our
brethren across the sea did not even know what we were doin^
away in the forests of Newfoundland. Our little company raised
and exi)ended over a million and a quarter of dollars befoi'e an
Englishman paid a single pound sterling. Our only support out-
side was in the liberal character and steady friendship of the Gov-
ernment of Newfoundland, for which we were greatly indebted
to ^Ir. E. ^I. Archibald, then Attorney-General of that colony,
and now British Consul in New York. And in preparing for an
ocean cable, the first soundings across the Atlantic were made by
American oflieers in American ships. Our scientific men had
taken great interest in the subject. The U. S. ship ' Dol])hin,' dis-
covered the telegrajjhic plateau as early as 1853 ; and the U. S.
ship 'Arctic ' sounded across from Newfoundland to Ireland in 1856,
a year before H. M.'s ship ' Cyclops,' under command of Captain
Da3-man, went over the same course. This I state, not to take
aught from the just praise of England, but simply to vindicate the
truth of history.

" It was not till 185G — ten years ago — that the enterpi-ise had
any existence in England. In that summer I went to London,
and there, with Mr. John W. Brett, Mr. Charles Bright, and Dr.
Whitehouse, organized the Atlantic Telegraph Company. Sci-
ence had begun to contemi^late the necessity of such an enter-
prise ; and the great Faraday cheered us with his loft}'^ enthu-
siasm. Then for the fii'st time was enlisted the support of English
capitalists ; and then the British Government began that generous
course which it has continued ever since — ofi'ering us ships to
complete soundings across the Atlantic, and to assist in laying the
cable, and an annual subsidy for the transmission of messages.

MECHANICS AND USEFUL ARTS. 15

The expedition of 1857, and the two expeditions of 1858, were
joint enterprises, in which the ' Niagara ' and ' Susqnehanna 'took
part with the ' Agamemnon,' the ' Leopard,' the ' Goi-gon,' and the
' Valorous ' ; and the officers of both navies worked with generous
rivalry for the same great object. The capital of the Atlantic
Telegraph Company (£350,000) — except one-qnarter, which was
taken by myself — was subscribed wholly in Great Britain. Tiie
directors were almost all English bankers and merchants, though
among them was one gentleman whom we are proud to call an
Amencan — Mr. George Peabody — a name honored in two coun-
tries, since he has showered his princely benefactions upon both.

"With the history of the expedition of 1857-8 you are familiar.
On the third trial we gained a brief success. The cable was laid,
and for four weeks it worked, — though never very brilliantly, —
never giving forth such rapid and distinct flashes as the cables of
to-day.

*' It spoke, tliough only in broken sentences. But while it lasted
no less than 400 messages were sent across the Atlantic. You all
remember the enthusiasm which it excited. It was a new thing
under the sun, and for a few weeks the public went wild over it.
Of course, when it stopped, the reaction was very great. Peoj^le
grew dumb and suspicious. Some thought it was all a hoax ; and
many were quite sure that it never worked at all. That kind of
odium we have had to endure for eight years, till now, I trust, we
have at last silenced the unbelievers.

" After the failure of 1858 came our darkest days. When a thing
is dead, it is hard to galvanize it into life. It is more difficult to
revive an old enterprise than to start a new one. The freshness
and novelty are gone, and the feeling of disappointment discour-
ages further eflbrt.

" Other causes delayed a new attempt. This country had become
involved in a tremendous war ; and while the nation was strug-
gling for life, it had no time to spend in foreign enterprises.

"But in England the project was still kept alive. The Atlantic
Teleoraph Company kept up its organization. It had a noble
body of directors, who had faith in the enterprise, and looked be-
yond its present low estate to ultimate success. I cannot name
them all, but I must speak of our Chairman, — the Right Hon.
James Stuart Wortley, — a gentleman who did not join us in the
hour of victory, but in what seemed the hour of despair, after the
failure of 1858, and who has been a steady support through all
these years.

"Ail this time the science of submarine telegraphy was making
progress. The British Government appointed a commission to
investigate the whole subject. It was composed of eminent scien-
tific men and practical engineers — Galton, Wheatstone, Fair-
bairn, Bidder, Varley, and Latimer, and Edwin Clark — with the
Secretary of the Company, JMr. Saward — names to be held in
honor in connection with this enterprise, along with those of other
English engineers, such as Stephenson, and Brunei, and Wliit-
worth, and'Penn, and Lloyd, and Joshua Field, who gave time
and thought and labor freely to this enterprise, refusing all com-

16 ANXTJAL OF SCIENTIFIC DISCOVERT.

pensation. This commission sat for nearly two years, and spent
many thousands of pounds in experiments. The result was a
clear conviction in every mind that it was possible to lay a tele-
graj)h across the Atlantic. Science was also being all the while
applied to practice. Submarine cables were laid in dificrent seas •
— in the Mediterranean, in the Red Sea, and in the Persian Gulf.
*' When the scicntilic and engineering jjroblems were solved,
we took heart again, and began to pi-epare for a fresh att(^mpt.
This was in 18Ga. In this country — though the war was still rag-
ing — I went from city to city, holdinir meetings and trying to
raise capital, tnit with ))oor success. IVIcn came and listened, and
said ' it was all very line,' and ' hojjcd I would succeed,' but did
nothing. In one of the cities they gave me a large meeting, and
passed some beautiful rosohUions, and appointed a committee of
'solid men' to canvass tlie city, but I did not get a solitary sub-
scriber! In this city I did lietter, though money came by the
hardest. By personal solicitations, encouraged by good friends, I
succcedt'(l in raising £70,000. Since not many had I'aitli, I must pre-
sent one exami)l(' to tiie contrary', though it was not till a year later.
When almost all deemed it a hopeless scheme, one gentleman
came to me and purchased stock of the Atlantic Telegraph Com-
pany to tlie amount of $100,000. That was Mr. Loring Andrews,
who is here this evening to see his faith rewarded. But at the
time 1 speak of, it was plain that our main hope must be in Eng-
land, and I went t<j London. There, too, it dragged heavily.
There was a profound discouragement. JNIany had lost before,
and were not willing to thnjw more money into the sea. We
needed £000,000, and with our utmost efforts we had raised less
than half, and there the enterprise stood in a dead lock. It was
l^lain that Ave must have liclp from some new quarter. I looked
around to lind a man who had broail shoulders, and could cany a
heavy load, and who would be a giant in the cause. It was at
this time I was introduced to a gentleman, whom I would hold
up to the American public as a, specimen of a great-hearted Eng-
lishman, ]\Ir. Thomas Brassey. 1 went to see him, though with
fear and trembling. lie received me kindly, but put me through
such an examination as I never had before. I thought I was
in the witness-box. He asked every possible question, but my
answers satisfied him, and he ended by saying it was an enteri^rise
which ought to be carried out, and that he would be one of ten
men to furnish the money to do it. This was a pledge of £60,000
sterling ! Encouraged by this noble offer, I looked around to
find another such man, though it Avas almost like trjing to find
two Wellingtons. But he was found in Mr. John Pender, of
Manchester. I went to his office one day in Loudon, and we
walked together to the House of Commons, and before we got
there he said he would take an equal share with Mr. Brassey.

" The action of these two gentlemen was a turuing-i^oiut in the
history of our enterprise ; for it led shortly after to a union of the
well-known firm of Glass, Elliot & Co. with the Gutta Percha
Company, making of the two one grand concern known as ' The
Telegraph Construction and Maixitenance Company,' which in-

MECHANICS AND USEFUL ARTS. 17

-eluded not only Mr. Brassey and JNIr. Pender, but other men of
great wealth, such as Mr. George Elliot, and Mr. Barclay of Lon-
don, and Mr. Henry Bewley of DuiDlin, and which, thus rein-
forced with immense capital, took up the whole enterprise in its
strong arms. AVe needed, I have said, £600,000, and with all
our efforts in England and America we raised only £285,000.
This new company now came forward, and offered to take the
whole remaining £315,000, besides £100,000 of the bonds, and to
make its own profits contingent on success. Mr. Richard A.
Glass was made Managing Director, and gave energy and vigor
to all its departments, being admirably seconded by the Secretary,
Mr. Shuter.

" A few days after half a dozen gentlemen joined together and
bought the ' Great Eastern,' to lay the cable ; and at the head of
this company was placed Mr. Daniel Gooch, a member of Parlia-
ment, and Chairman of the Great Western Railway, who was with
us in both the exi^editions which followed.

" The good fortune which favored us in our ship favored us also
in our commander. Many of you know Capt. Anderson, who was
for years in the Cunard line. How well he did his part in two
expeditions the result has proved.

"Thus organized, the work of making a new Atlantic cable was
begun. The core was prepared with infinite care, under the able
superintendence of Mr. Chatterton and Mr. Willoughby Smith,
and the whole was completed in about eight months. As fast as
ready, it was taken on board the ' Great Eastern ' and coiled in
three enormous tanks, and on the 15th of July, 1865, the ship
started on her memoral)le voyage.

" I will not stop to tell the story of that expedition. For a week
all went Avell; we had paid out 1,200 miles of cable, and had
only 600 miles further to go, when, hauling in the cable to remedy
a fault, it parted and went to the bottom. That day I can never
forget — how men paced the deck in despair, looking out on the
broad sea that had swallowed up their hopes ; and then how the
brave Canning for nine days and nights dragged the bottom of
the ocean for our lost treasure, and, though he grappled it three
times, failed to bring it to the surface. The story of that expe-
dition, as written by Dr. Russell, who was on board the ' Gi'eat
Eastern,' is one of the most marvellous chapters in the whole his-
tory of modern enterprise. We returned to England defeated,
yet full of resolution to begin the battle anew. Measui-es were
at once taken to make a second cable, and fit out a new exjjedi-
tion ; and with that assurance I came home last autumn.

" In December I went back again, when lo, all our hopes had
sunk to nothing. The Attorney-General of England had given
his written opinion that we had no legal right, without a special
act of Parliament (v/hich could not be obtained under a year), to
issue the new 12 per cent, shares, on which we relied to raise our
capital. This was a terrible blow. The works were at once
stopped, and the money which had been paid in returned to the
subscribers. Such was the state of things only ten months ago.
I reached London on the 24th of December, and the next day was
2*

18 ANNUAL OF SCIENTIFIC DISCOVERT.

not a ' meny Christmas' to rae. But it was an incxpressiblo
comfort to have the counsel of such men as Sir Daniel Gooch and
Sir Richard A. Glass ; and to hear stouthearted Mr. Brassey t(ill
us to go ahead, and, if need wei'c, he Avould put down £00,000
more ! It was linally concluded that the best course was to
organize a new company, which should assume the work, and so
originated the Anglo-American Telegraph Compan}'. It was
formed b\' ten gentlemen who met around a table in London, and
])ut down £10,000 apiece. The great Telegraph Construction
and Maintenance Company, umlaunted by tlw failure of last
year, answered us with a subscription of £100,000. Soon after
the books were opened to the public, through tlie banking-house
of J. S. Morgan & Co., and in fourteen days we had raised the
whole £600,000. Then the work began again, and went on with
speed. Never was greater energy infused into any enteiprise.
It was only the 1st day of March tliat the new company was
formed, and was registered as a company the next day ; and yet
such was the vigor and dispatch that in five months from that day
the cable had been manufactured, sliii)ped on the ' Great East-
ern,' stretched across the Atlantic, and was sending messages,
literally swift as lightning, from continent to continent.

" Yet this was not a ' lucky hit ' — a fine run across the ocean in
calm weatlier. It was the worst weather I ever knew at that
season of the year. We had fogs and storms almost the whole
way. Our success was the result of tiie highest science com-
bined with practical experience. Everything was perfectly or-
ganized, to tiie minutest detail. We had on board an admirable
staff of officei'S ; sueh men as Ilalpin and Beckwith ; and engineers
long used to this business, such as Canning, and Clifford, and
Temple ; and electricians, such as Prof. Thomson, of Glasgow,
and Willoughby Smith, and Laws; while Mr. C. F. Varley, our
companion of the year before, who stands among the first in
knowledge, in practical skill, remained with Sir Richard Glass at
Valentia, to keep watch at that end of the line ; and Mr. Latimer
Clark, who was to test the cable when done. Of these gentlemen,
Prof. Thomson, as one of the eai'liest and most eminent electri-
cians of England, has received the distinction of knighthood.
England honors herself when she thus pays honor to science ; and
it is fit that the government which honored chemistry in Sir
Humpln-y Davy, should honor electrical science in Su* William
Thomson.

"But our work was not over. After landing the cable safely at
Newfoundland, we had another task — to return to mid-ocean and
recover that lost in the expedition of last year. This achievement
has perhaps excited more surprise than the other. Many even
now ' don't understand it,' and every day I am asked ' how it
was done ? ' Well, it does seem rather difficult to fish for a jewel
at the bottom of the ocean, two and a half miles deep. But it is
not so vei-y difficult — when you know how. You may be sure
we did not go a-fishing at random, nor was our success mere
' luck ; ' it was the triumph of the highest nautical and engineer-
ing skill, W^e had four ships, and on boai'd of them some of the

MECHANICS AND USEFUL AETS. 19

best seamen in Eno:]and, men who knew the ocean as a hunter
knows every trail in the forest.

" There was Capt. Moriarty, who was in the * Agememnon' in
1857-8. He was in the 'Great Eastern' hist year, and saw tlie
cable when it broke ; and he and Capt. Anderson at once took
their observations so exact that they could go right to the spot.
After finding it, they marked the line of the cable by a row of
buoys ; for fogs would come down, and Shut out sun and stai's, so
tliat no man could take an observation. These buoys were
anchored a few miles apart. They were numbered, and each had
a flag-staflf on it, so that it could be seen by day ; and a lantern
by night. Thus having taken our bearings, we stood off three or
four miles, so as to come broadside on, and then casting over the
graimel, drifted slowly down upon it, dragging the bottom of the
ocean as we went. At first it was a little awkward to fish in such
deep water, but our men got used to it, and soon could cast
a grapnel almost as straight as an old whaler throws a harpoon.
Our fishing-line was of formidable size. It was made of rope,
twisted with wires of steel, so as to bear a strain of 30 tons. It
took about two hours for the grapnel to reach bottom, but we
could tell when it struck. I often went to the bow, and sat on the
rope, and could feel by the quiver that the grapnel was drao-gino-
on the bottom two miles under us. But it was a very slow busi-
ness. We had storms and calms and fogs and squalls. Still we
worked on, day after day. Once, on the 17th of August, we got
the cable up, and had it in full sight for five minutes, a long, slimy
monster, fresh from the ooze of the ocean's bed, but our men
began to cheer so wildly that it seemed to be frightened, and sud-
denly broke away, and went down into the sea. This accident
kept us at work two weeks longer ; but, finall}^ on the last nio-ht
of August, we caught it. We had cast the grapnel thirty times. ° It
was a little before midnight on Friday night that we hooked the
cable, and it was a little after midnight Sunday morning when we
got it on board. What was the anxiety of those twenty-six hours !
The strain on every man's life was like the strain on the cable
itself. When finally it appeared, it was midnight ; the lights of
the ship, and in the boats around our bows, as they flashed in the
faces of the men, showed them eagerly watching for the cable to
appear on the water. At length it was brought to the surface.
All who were allowed to approach crowded^forward to see it.
Yet not a word was spoken ; only the voices of the officers in
command were heard giving orders. All felt as if life and death
hung on the issue. It was only when it was brought over the
bow and on to the deck that men dared to breathe. Even then
they hardly believed their eyes. Some crept toward it to feel of
it, to be sure it was there. Then we carried it along to the elec-
tricians' room, to see if our long sought for treasure was alive or
dead. A few minutes of suspense, and a flash told of the light-
ning current again set free. Then did the feeling long pent up
burst forth. Some turned away their heads and wept. Others
broke into cheers, and the cry ran from man to man, and was
heard down in the engine-rooms, deck below deck, and from the

20 ANNUAL OF SCIENTIFIC DISCOVERT.

boats on the water, and the other ships, while rockets licrhted up
the darkness of the sea. Then with thankful hearts we turned
our faces again to the west. But soon the wind rose, and for
tliirty-six hours we wei'e exposed to all the danf^ers of a storm on
the Atlantid. Yet, in the very height and fury of the gale, as 1 sat
in the electricians' room, a flash of light came up from the deep,
Avhich, having crossed to Ireland, came back to me in mid-ocean,
telling that those so dear to me, whom I had left on the banks of
the Hudson, were well, and following us with their wishes and
their i)rayers. Tiiis was like a whisper of God from the sea, bid-
ding me keep heart and hojie. The ' Great Eastern' l)ore herself
proudly through the storm, as if she knew that the vital cord
whiih was to join two hemispheres hung at her stern ; and so, on
Saturda}', the 7rh of September, we brought our second cable
safely to the shore.

" Having thus accomplished our work of building an ocean tel-
egraph, we desire to make it useful to the public. To this end, it
must be kept in perfect order, and all lines connected with it.
The very idea of an electric telegraph is, an instrument to send
messages instantaneously. When a dispatch is sent from New
York to London, there must be no uncertainty about its reaching
its destination, and that promptly. This we aim to secure. Our
two cables do their part wt-U. There are no way-stations between
Ireland and Newfoundland where messages have to be repeated,
and tiie lightning never lingers more than a second in the bottom
of the sea. To those who feared that they might be used up or
wear out, I would say, for their relief, that tiie old cable works a
little better than the new one, but tiiat is because it has been
down longer, as time improves the quality of gutta percha. But
the new one is constantlv growing l)etter. To show how delicate
are these wonderful cords, it is enough to state that they can be
worked with the smallest battery power. When the first cable
was laid in 1858, electricians thought that to send a current 2,000
miles, it must be almost like a stroke of lightning. But God was
not in the earthquake, but in the still, small voice. The other
day Mr. Latimer Clark telegraphed from Ireland across the ocean
and back again, with a battery foi'med in a lady's thimble ! And
now Mr. Collett writes me from Heait's Content: 'I have just
sent my compliments to Dr. Gould, of Cambridge, who is at
Valentia, with a battery composed of a gun-cap, with a strip of
zinc, excited by a drop of water, the simple bulk of a tear ! ' A
telegraph that will do that, we think nearly perfect. It has never
failed for an hour or a minute. Yet there have been delajs in
receiving messages from Europe, but these have all been on the
land lines or in the Gulf of St. Lawrence, and not on the sea
cables. It was very painful to me, when Ave landed at Heart's
Content, to find any interruption here ; that a message which
came in a flash across the Atlantic should be delayed twenty-four
hours in crossing 80 miles of Avater. But it was not my fault.
My associates in the NcAvfoundland Company Avill bear me wit-
ness, that I entreated them a year ago to I'cpair the cable in the
Gulf of St. Lawrence, and to put our land lines in perfect order.

MECHANICS AND USEFUL ARTS. 21

But they thought it move prudent to await the result of the late
expedition before making further large outlay. We have thei-e-
fore had to work hard to restore our lines. But in two weeks our
cable across the Gulf of St. Lawrence was taken up and repaired.
It was found to have been broken by an anchor in shallow water,
and, when spliced out, proved as jDcrfect as when laid down ten
years ago. Since then a new one has been laid, so that we have
there two excellent cables.

" On land the task was more slow. You must remember that
Newfoundland is a large countiy ; our line across it is 400 miles
long, and runs through a wilderness. In Cape Breton we have
another of 140 miles. These lines were built twelve years ago,
and we waited so long for an ocean telegraph that they have
become old and rusty. On such long lines, unless closely watched,
there must be sometimes a break. A few weeks ago, a storm
swe^at over the island, the most terrific that had been known for
twenty years, which strewed the coast with shi2Dwrecks. This
blew down the line in many places, and caused an interruption of
several daj's. But it was quickly repaired, and we are trying to
guard against such accidents again. For three months we have
had an army of men at work, under our faithful and indefatigable
Superintendent, Mr. A. M. Mackay, z-ebuilding the line, and now
they I'eport it nearly complete. On this we must rely for the
next few months. But all winter long these men will be making
their axes heard in the forests of Newfoundland, cutting thousands
of poles, and as soon as the spring opens will build an entirely
new line along the same route. With this double line complete,
with frequent station-houses, and faithful sentinels to watch it, we
feel pretty secure. At Port Hood, in Nova Scotia, we connect
with the Western Union Telegraph Comjiany, which has engaged
to keep as many lines as may be necessary for European business.
This we think will guard against failures hereafter. But to make
assurance doubly sure, we shall in the spring build still another
line by a separate route, crossing over from Heart's Content to
Placentia, which is about 100 miles, along a good road, where it
can easily be kept in order. From Placentia a submarine cable
will be laid across to the French island of St. Pierre, and thence
to Sydney, in Cape Breton, where again we strike a coach-road,
and can maintain our lines without difficulty. Thus we shall
have three distinct lines, with which it is hardly possible that there
can be any delay. A message from London to Ncav York passes
over four lines: from London to Valentia; from "Valentia to
Heart's Content ; from there to Port Hood ; and from Port Hood
to New York. It always takes a little time for an operator to
read a message and prejiare to send it. For this allow five min-
utes at each station ; that is enough, and I shall not be content
till we have messages regularly from London in twenty minutes.
One hour is ample (allowing ten minutes each side for a boy to
carry a dispatch) for a message to go from Wall Street to the
Royal Exchange, and to get an answer back again. This is what
we aim to do. K for a few months there should be occasional
delays, we ask only a little patience, remembering that our

22 ANNUAL OF SCIENTIFIC DISCOVERT.

machinery is new, and it takes time to get it well oiled and nin-
nin<>: at I'nll speed. But after that, I trust we shall be able to
satisfy all the demands of the public.

"A word about the tariff. Complaint has been made that it was
so hi<i:h as to be very oppressive. I beg all to remember, that it
is only three months and a half since the cable was laid. It was
laid at a gr(>at cost and a great risk. Different companies had
sunk in their attempts $r2,000,(X)0. It was still an experiment,
of which the result was doubtful. This, too, might prove a costly
failure. Even if successful, we did not know liow long it would
work. Evil i)rophcts in both countries predicted that it would not
last a month. If it did, we were not sure of having more than
one cable, nor how much work that one could do. Now these
doubts are resolved. AVe have not only one cable but two, Ijoth
in working order; and Ave lind, instead of five words a minute,
we can send fifteen. Now we are free to reduce the tariff. Ac-
cordingly, it has been cut down one-half, and I hope in a few
montlis we can bring it down to one-quarter. 1 am in favor of
reducing it to the lowest point at which we can do the business,
keeping the lines working day and night. And tiien, if the work
grows upon us so enormously that we cannot do it, why, we must
go to work and lay more calile."

In addition to the precedinjj remarks of Mr. Field, a few addi-
tional details may well be added to complete the histoiy. Four
attempts were made to lay a cable across the Atlantic before suc-
cess was attained. In the first attempt, in 1857, the cable gave
way owing to a strain being put on tlie paying-out machinery, by
the sudden dip of the Irish bank, which the ap2>aratus was neither
strong enough nor fl(!xible enough to withstand. The second
attempt was made in 1858, when the " Agamemnon" and the
"Niagai'a" met in mid-ocean, effected a sj^lice, and steering in
opposite directions ultimately laid the cable, which in a few
weeks transmitted about 400 messages, and then failed. The
attempts of 1865 and 1860 have been sufficiently described by Mr.
Field. The great fact that a cable could be laid between Euro2Je
and America, and that messages could be sent and received
through its length, Avas practically demonstrated in 1858; the
failure of the cable of 1865 aa'us due to mechanical causes, evident
enough and easily remedied, as the success of the cable of 1866
fully shoAvs.

The cable of 1858 had for a conductor a copper sti-and of^seven
AA-ires, six laid around one ; Aveight, 107 lbs. per nautical mile.
The insulator Avas of gutta percha, laid on in thi-ee coverings;
weight, 261 lbs. per nautical mile. The outer coat Avas composed
of 18 strands of charcoal iron-Avire, each strand made of seven
wires, tAvisted six around one, laid equally around the core, Avhich
had previously been padded Avith a serving of tarred hemp.
Breaking strain, three tons five CAvt. ; capable of bearing its OAvn
weight in a trifle less than five miles depth of Avater. Length of
cable, 2,174 nautical miles ; diameter, five-eighths of an inch.
In the cable of 1865, the conductor Avas a copper strand of seven
wii-es, six laid around one ; weight, 300 lbs. per nautical mile ;

, MECHANICS AND USEFUL ARTS. 23

embedded in Chatterton's compound. Insulation was effected
with gutta percha and Chatterton's compound. Weight, 400 lbs.
per nautical mile. The outer coat was 10 wires drawn from
Webster and Horsfall's homogeneous iron, each wire surrounded
with tarred Manila rope, and the whole laid spii-ally around the
coi'e, which had previously been padded with a serving of tarred
jute yarn. Breaking strain, seven tons, 15 cwt. ; capable of
bearing its own weight in 11 miles depth of water. Length of
cable, 2,300 nautical miles ; diameter, one inch.

The cable of 1866 has for a conductor a copper strand of seven
wires, six laid around one ; weight, 300 lbs. per nautical mile ;
embedded for solidity in Chatterton's compound. The insulator
is four layers of gutta percha laid on alternately with thinner lay-
ers of Chatterton's compound ; weight, 400 lbs. per nautical mile.
The outer coat is 10 solid wires drawn from Webster and Hors-
fall's homogeneous iron and galvanized, each wire surrounded
separately with five strands of white Manila yarn, and the whole
laid spirally around the core, which had previously been padded
with a serving of tarred hemp. The breaking strain is eight
tons two cwt., and it is capable of bearing its own weight in 12
miles depth of water. The length of this cable is 2,730 nautical
miles, part of which was to be used for completing the cable that
parted in 1865. Diameter, one inch.

In laying the Atlantic cables, four main risks had to be encoun-
tered, all of which in the present one have been successfully
passed throuo-h ; 1st, the successful and rapid laying of the shore
end ; 2d, passing down the tremendous submarine incline known
as the "Irish bank;" 3d, passing over a short steep valley,
where the water sinks to almost as great a depth as in mid-ocean ;
4th, and greatest, the laying of the cable for a distance of more
than 100 miles through a depth of 2,400 fathoms, or 15,000 feet of
water ; this passed over, the ocean begins gradually to shallow to
100 fathoms on the Newfoundland coast. The present cable was
landed on the American coast in 50 fathoms in Heart's Content
Bay, one of the most easterly spurs of rocky headland on the
south of Newfoundland ; the place chosen for its landing is a
deep, rocky inlet, similar to but much larger than Foilhommerum
Bay, on the Irish end of the cable ; this is more sheltered than
Bull's Bay, where the cable of 1858 was successfully landed.

The European shore end of the cable of 1866 was landed at
Foilhommerum Bay, on the coast of Ireland, July 7, 1866, at
^noon ; by 3 A. M. of the 8th, the full length of 30 miles was paid
out, signalled through, and its insulation and conductivity found
perfect. On July 12th, the " Great Eastern " commenced making
the splice with buoyed shore end : as Boon as that was completed
and found perfect, the great work of laying the cable commenced.
For the first 250 miles, that is till over the " Irish bank," the cable
made in 1865 was used, after that the new cable only ; the reason
for making this difterence was that the new cable is more strongly
made than that of 1865, and was therefore reserved for the deepest
water. The route taken was 30 to 35 miles south of the broken

24 ANNUAL OF SCIENTIFIC DISCOVERT.

cable of last year, so tliat in jjrapplinp: for its recovery, there
■W'ouUl be no (lani^cr of i)ickiiif; up tlu^ new one.

One of the the most n'niarUablc cironmstances connectofl with
the layinoj of tlie oable of IHllG is the directness of the route taken
by the Great Ivistcrn, and the small percentage of slack of the
cal)lt> })ai(l out, compart'd with the distance run.

The log of the steanu-r shows:

Saturday, \Wi. — Distance run, 108 miles; cable paid out, 116
miles.

Sunday, loth. — Distance run, 128 miles; cable paid out, 139
miles.

Monday, IGih. — Distance run, 115 miles; cable paid out, 137
miles.

Tuesday, 17 th. — Distance run, 118 miles; cable paid out, 139
miles.

Wednesday, 18th. — Distance run, 105 miles ; cable jjaid out, 125
miles.

Thursday, 19th. — Distance run, 122 miles; cable paid out, 129
miles.

Friday, 20th. — Distance inin, 117 miles; cable paid out, 127
miles.

Saturday 21st. — Distance run, 122 miles; cable paid out, 136
miles.

Sunday, 22d. — Distance run, 123 miles; cable paid out, 133
miles.

Monday, 23d. — Distance run, 121 miles; cable paid out, 138
miles.

Tuesday, 2ith. — Distance run, 121 miles; cable paid out, 135
miles.

Wednesday, 2bth. — Distance run, 112 miles; cable paid out, 130
miles.

Thursday, 2Uh. — Distance run, 128 miles ; cable paid out, 134
miles.

Friday, 21th. — Distance run, 112 miles; cable paid out, 118
miles; which, with shore end off Valentia, distance 27 miles,
cable paid out 29 miles, makes distance run 1,6G9 miles, and paid
out, 1,H64 miles.

On the 29th of July, the New Yoi-k papers were supplied with
the news from Central Europe only 30 hours old.

One of the most remarkalile feats of engineering of any age
was the picking up of tlie cal)le of 1865, lost at sea, August 2d ; at
the time of parting, 1,213 miles of cable had been j)aid out, and
all attempts to regain it had Ijeen useless on account of the ineffi- ■
cacy of the apparatus used. Having laid the new cable, the " Great
Eastern " sailed Aug. 9th, to pick u}) the old. The dragging for the
cable commenced Aug. 12th, resulting in bringing it to the sur-
face on the 17th ; it slipped from its fastenings and sunk, four
times ; but on the fifth trial, after casting the grapnel 30 times, a
permanent union was made with the coil on board the '• Great East-
ern," on September 2d. It was found uninjured and in perfect
working order. The grappling ropes were 20 miles long, seven
and a half inches in circumference, of the same strands of the

MECHANICS AND USEPUL ARTS. 25

cable ; the wire being of steel running through the Manila
covering.

The new cable is superior to the old in strength and conductiv-
ity, from its enlarged copper wire, and especially by its increased
and more carefully guarded insulation. In consideration of these
qualities, of the delicate instruments for detecting faults and for
Avorking through them when detected, and of the high degree of
perfection to which electrical science as applied to telegraphy has
now attained, it may be confidently asserted that the new Atlantic
cable will be permanently successful.

Says the " New York Independent:" "On Monday, July 30,
Mr. Field received a message of congratulation from Mr. Ferdinand
de Lesseps, the projector of the Suez Canal. It was dated at
Alexandria, in Egypt, the same dny, at half-past 1 p. M., and re-
ceived in Newfoundland at half-jjast 10 A. M. Let us look at the
globe, and see over what a space that message flew. It came
from the land of the Pharaohs and the Ptolemies ; it passed along
the shores of Africa, and under the Mediterranean Ocean more
than a tliousand miles, to Malta ; it then leaped to the continent
of Europe, and shot across Italy, over the Alps and through
France, under the English Channel to London ; it then flashed
across England and Ireland, till from the cliffs of Valentia it
struck straight into the Atlantic, darting down the submarine
mountain which lies off the coast, and over all the hills and val-
le3's which lie beneath the watery jjlain, resting not till it touched
the shore of the ' New World.' In that mornina-'s flio;ht it had
passed over one-jourth of the earth's surf;ice, and so far outstrip-
ped the sun in its course that it reached its destination three hours
before it was sent ! To understand this, it must be remembered
that the earth revolves from west to east, and when it is sunrise
here it is between 8 and 9 o'clock in Alexandria, in Egypt ; and
when it is sunset here, it is nearly 9 o'clock in the evening there."

THE NORTH ATLANTIC TELEGRAPH.

The magnitude and serious nature of the transmitting difficul-
ties existing in all long unbroken sea lines, has led to the con-
struction of what is known as the Russian-American line, — a land
line of telegraph intended to reach New York from St. Peters-
burg by Avires through Siberia and on to San Francisco, Avith a
short sea section across Bchring's Straits, a total distance of about
12,000 miles. This Russian- American line is already far advanced
towards comi^letion. But by far the most important line of tele-
graphic communication between England and America is that to
be immediately carried into effect via Scotland, the Faroe Islands,
Iceland, Greenland, and the coast of Labrador; and knoAvn as the
Nortli Atlantic Telegrajih. A glance at the map in the direction
pointed out will at once shoAV tliat convenient natural landing
stations exist, breaking up the calsle into four short lengths or sec-
tions, instead of the necessitous employment of one continuous
length, as betAveen Ireland and NcAvfoundland. It will also be
found that the aggregate lengths of these sections is Avithin a very
few miles the same as that of the Anglo-American cable. Not
3

26 ANNUAL OF SCIENTIEIC DISCOVERY.

only will this subdivision of the cable reduce mechanical risks in
sul)merging, but, what is of fur nioi-c importance, the retardation
offered to tlie passage of the current through the several short
sections is almost as nothing when compared with that of the un-
broken length of 2,000 miles. Speeil of transmission is obtained ;
and by that means a reduced tariff for i)uljlic transmissions over
the wire. Indeed, such will be tlie advantages gained in this
respect that the present rate by the Anglo-American line of 20s.
per word, will be charged on the new route at 2s. (5d., or even a
less sum. In examining more closely the nature of tliis intended
northern line, it will bv. found that the lengths of the several
sections of ealjle between England and America are as follows :
Scotland to the Faroe Isles, 250 miles; Faroe to Iceland, 210
miles ; Iceland to Greenland, 7.30 miles ; Greenland to Labrador,
5-40 miles; or, in rouml numbers about 1,780 miles. The several
lengths of cable will be connected together by special land lines
through the Faroes (27 miles), and in Iceland (280 mikis), and a
length of about GOO miles of land wire to be erected in Labrador,
will com])lete the circuit, with the existing American system, on
to New York. The average depth of the ocean between Scotland
and the Faroe Isles is only 150 lathoms, the greatest depth G83
fathoms. Between the Faroes and Iceland, 250 fathoms, with
about the same maximum depth. Between Iceland and Julian-
shaad, the intended landing-place of the cable in Greenland, the
greatest depth is 1,550 fathoms, and between Greenland and Lab-
rador rather over 2,000 fathoms. These lengtlis of cable and
depths of ocean are both not only navigable, but practicable ; and
no difficulties in the working exist that are not already known l)y
reference to the practical working of existing cables under the
conditions of similar lengths and depths. As regards the presence
of ice, it must be remembered that it is only at certain seasons of
the year that the southwest coast of Greenland is closed by the ice ;
at other times this ice breaks up, and the coast is accessible to the
Danish and otlier trading vessels frequenting the port and harbor
of -Julian^haad, the proposed station and landing-place of the
cables, and at such times the cables will I)e laid. Reference to
the depth of the soundings up the Julianshaad fjiord will at once
indicate the security of tlie shore ends of tlie cal:)les from inter-
fei'ence from ice Avhen submerged. The landing-places of the
cable in Iceland are likewise in no way liable to be disturbed by
ice of such a nature as to cause damage to the cable ; and on tlie
Labrador coast, the risk of injury to the cable cannot be consid-
ered greater than that to Avhich the Anglo-American shore ends
are exposed in the vicinity of Newfoundland Bank. — J. Holmes,
in Reports of British Association for 1866.

TUNNEL UNDER LAKE MICHIGAN AT CHICAGO, ILL.

The following account of one of the most remarkable and suc-
cessful feats of American engineering is compiled from various
sources, princiiially the llejiorts of the Board of Public Works,
Chicago, the "Scientific American," and the Boston " Coumion-
wealtii." This work is now virtually completed, and for boldness

MECHANICS AND USEFUL ARTS. 27

of conception and engineering skill can compai-e with the proudest
achievements of any age or country. The growth of the city of
Chicago has been marvellous, even for America, and its water
supply, always insufficient, and of late years unwholesome from
the filth poured into the lake near the shore by the sewers, had
become a source of great anxiety to its citizens, when it was pro-
posed to take water from the lake two miles from shore, and con-
duct it to the city through a tunnel under the bed of the lake.
Many engineers doubted the practicability of the undertaking, and
the estimates of its probable cost varied from $250,000 to $6,000,-
000. Surveys of the lake bed by means of an auger inclosed
in a tube, revealed the favorable circumstance of a continuous
underlying stratum of hard blue clay. The contract was awarded
to Messrs. Dall and Gowan in October 1863, for $315,139. They
have expended, it is said, more than double that amount, and the
total cost will probably be not far from a million dollars. Work
was commenced on the shore end of the tunnel, March 17, 1864 ;
and its completion in so short a time is due principally to the sldll
and energy of the City Engineer, Mr. E. S. Chesbrough, formerly
connected with the Cochituate Water Works at Boston.

The shore-end shaft consists of sections of great cast-iron tub-
ing, about 36 feet long and 9 in diameter, let into the earth by
simply excavating beneath them, and allowing them to sink as
the earth was removed. Having in this way worked through the
sand and into the blue clay, which forms the bed of the lake, the
shaft was narrowed to 8 feet, and carried down over 40 feet
lower, with brick walls a foot thick. This shaft was sunk four
feet Ipwer than the lake shaft, causing a descent of two feet per
mile in the tunnel to facihtate emptying when required. From
the shore end the tunnel extends two miles in a straight line, at
right angles to the shore.

At the lake end of the tunnel the greatest engineering difficulty
and triumph occurred. Many engineers believed that it would be
impossible to make a permanent structure at this point, on ac-
count of the violent storms on the lake. It was, however, effected
by a huge wooden crib or coffer-dam, built, like a ship, on the
shore, launched, and towed to its destined location.

This immense crib was launched July 26, 1865 ; it is 40 feet 6
inches high, pentagonal, in a circumscribing circle of 98 feet 6
inches in diameter. It is built of logs one foot square, and con-
sists of three walls, at a distance of 11 feet from each other, leav-
ing a central pentagonal space having an inscribed circle of 25
feet, within which is fixed the iron cylinder, 9 feet in diameter,
to run from the water line to the tunnel, 64 feet below the surface
and 31 feet below the bed of the lake. The crib is very strongly
built, containing 750,000 feet of lumber, board measure, and 150
tons of iron bolts, and weighs about 1,800 tons. It was towed to
its position, two miles from the shore, on the same day, and the
process of sinking began by opening sluices and placing some 600
tons of stone in the bulkheads. The crib will hold 4,500 tons of
stone when filled, giving an extra weight of 3,900 tons for steady-
ing against the waves. As built it will stand about seven feet

28 ANNUAL OF SCIENTIFIC DISCOVERT.

nbove the water line, but, -when filled, another five feet Avill bo
add I'll.

The ano^les of the crib were armored with iron two and a half
inches tliiek. Tin' three distinet walls or shells, one wilhin an-
other, WL-re t'ach construeted of TJ-int-h S([uare timln'r, eaulkcd
watei'-ti;^ht like a ship, and all three braced and girded together
in every direction, with irons and timbers, to the utmost possible
pitch of nu'i'hanical strength. Within these sjjaces were con-
struct«'d fifteen caulked and water-tight coniparlmcnts, Avhich were
filled with clean rublde stone, alter the crib was placed in i)osi-
tion. By this means the crib was sunk to the bottom, where it
Mas finnly moor«d by cables reaching in every direction to Inige
screws forced ten feet into the bed t)f the lake. The water in
which it was sunk was thirty-five; feet deep, leaving five feet of the
structure altove the surface. This was in June, lUGo. The crib
had cost .'?inO,(Hi().

The crib stands 12 feet above the water line, giving a maximum
area of 1,"J00 feet whicli can be exposed at one sweep to the acti(jn
of the waves, reckoning the resistance as perpendicular. The
outside was thoroughly caulked, e(jual to a first-class vessel, with
three threads in each seam, the first and last iieing what is called
"horsed." Over all these there is a layer of lagging, which will
keep the caulking in jdace.and proti'ct the cril) proper from the
action of the waves. A covered i)latfonn or house was Ijuilt over
the crib, enabling the workmen to prosecute the work uninter-
rupted by rain or wind, and afi'ording a protection for the earth
brought up from the excavation, and permitting it to be carried
away by sctnvs, whose return carg()es ha\ e been l)ricks for the
lining of the tunnel. The top of the cylinder will be covered
with a grating to keep out floating logs, fish, &c. A sluice made
in the side of the crib will be opened to let in the water, and a
lighthouse will be built over all, serving the double purpose of
guarding the crib from injury by vessels,and of showing the way
to the harbor of Chicago.

The next thing was to sink a water-tight shaft within the well
of the crib and into the bottom of the lake some 30 feet further,
making G6 feet in all below the surface of the water. Seven great
ii'on cylinders, each nine feet long, nine feet in diameter, two and
a half inches thick, and weighing 30,000 pounds, were cast for
this purpose. The seven iron cylinders, making the iron part of
the shaft, and 03 feet of it in height, Avere one by one connected
by bolts, and lowered to the bottom of the lake within the 30 feet
open space in the centre of the crib. In the next to the upjier of
these cylinders are the gates or A'alves b}^ which the water will
be let in to and shut out from the tunnel. The cylinders Avere
then, after having been brought to exactly the right position,
forced downward into the stiff, hard clay of the bottom some 25
feet, the Avater being Avholly excluded.

The Avater was now pum])ed out, the tojj of the shaft Avas closed
as nearly as possible air-tight, and a powerful air-i:)ump, driven by
steam, commenced to exhaust the air also. As fast as a vacuum
could be created, the atmospheric pressure, added to its OAvn

MECHANICS AND USEFUL ARTS. 29

"weight of ovei' 100 tons, forced the huge shaft downward into the
bed of the lake with inconceivable force. Thus a depth was
reached and secured, at which it became perfectlj^ safe to carry-
forward the excavation, and complete the shaft to the level at
which the tunnel was to begin. The loose rubble-stone is finally
to be taken out of the water-tight compartments, one at a time,
and they will be re-filled with piers of solid masonry, laid in hy-
draulic cement, and united above the surface in some manner, so
as to present an immovable front on all sides against the force of
storms.

Both shafts having been completed, the excavation of the tun-
nel was commenced from both ends. The work was commenced
at the lake end about October, 1865 ; and the tunnel was finished
about Nov. 25, 1866. One-third of the length from the shore end
at the rate of about 17 feet a day, or about 3,200 feet, was com-
pleted before the commencement of the boring from the lake end.
About four-fifths of the tunnel was made from the shore side ; the
three intermediate cribs and shafts, at first proj^osed, were omit-
ted, and all the work carried on by the shafts at each end ; the
floor of the crib at the lake end Avas made of 12-inch timber in-
stead of plank.

The clear width of the tunnel is five feet, and the clear height
five feet two inches, the top and bottom arches being semi-circles.
It is lined with brick masonry eight inches thick, in two rings or
shells, the bricks being laid lengthwise of the tunnel, with tooth-
ing joints. The bottom of the inside surface of the bore at the
east end is 66 feet below the water-level, and has a gi'adiial slope
towards the shore of two feet per mile, falling four feet in the
whole distance, to admit of its being thoroughly emptied in case
of repairs, the water being shut off at the crib by means of a gate.
The work has been laid in brick eight inches thick all round, well
set in cement. The lower half of the bore is constructed in such
a manner that the bricks lie against the clay, while in the upper
half the bricks are wedged in Ijetween the brick and the clay,
thus preventing any danger which might result from the tremen-
dous pressure which it was feared might burst in the tunnel.

The work was continued night and day, with but sligjit inter-
mption, and at all seasons. A narrow railway was laid from the
foot of each shaft, as the work pi'ogressed, Avith turn-out cham-
bers for the passage of meeting trains ; and small cars, drawn by
mules, conveyed the excavated earth to the hoisting apparatus,
and brought back at every trip a load of brick and cement. The
men worked in gangs of five, at the excavation; the foremost
running a drift in the centre of the tunnel, about two and a half
feet wide, the second breaking down the sides of the drift, the
third trimming up the work to proper shape and size, and tl)e last
two loading the earth into the cars. The bricklayers followed
closely, only a few feet behind the miners. About 125 men were
employed in this work, in three relays, working eight hours each ;
the only cessation being from 12 o'clock Saturday night, to 12
o'clock Sunday night. A current of fresh air was constantly
forced through the tunnel by machineiy. It is remarkable that
3*

30 ANNUAL OF SCIENTIFIC DISCOVERY.

no serious accidcMit from earth, gas, or water, occurred iu the
■whole conrso of the work.

Tlie soil has Ix'cn foiuitl to be so uniform tliat only one leakage
of water tiuough the tunnel ever occurred, and that only distil-
ling througii a crevice at the rate of a bucketful in five minutes.
This occurred in Sojitembcr, 1.^05. Tlie workmen left in dismay,
but soon returned and r('j)aired the crevice. From tliat lime no
accidents of any importance have occurred to hinder the progress
of the work, witli the exception of one or two slight escajies of gas,
which resulted in notiiing serious. Several stones, varying from
the size of an i^'^'^ npwanls, have been met with, l)ut very few in
comparison with the great mass of clay. The only fault to be
found with the clay was, that it contained too much calcareous
matter U> make good bricks. The contractors claim that they
have lost numey on this account. The bricks formed of the clay
found iu the tunnel would not burn solidly, so that they were
obliged to get Ijricks elsewhere.

The lining (if the shore-shaft consists of twelve inches of the best
brick and cement, in three shells; about 4,000,000 bricks were
used in its construction.

On the IGth oH November, 18G6, the opposite gangs of work-
men were within two feet of each other, and this ])artition was
broke tinough on tiie following day in a formal manner by the
IJoard of Tublie Works. The accuracy of the measurements of
the engineer was such, that the two lines of excavation coincided
iu the centre within nine and one-half inches, and the lloors joined
with a dilVerence of only one inch.

Water is to be let into the lake-shaft by three gates, on differ-
ent sides, and at dilYerent heights. The lowest is five feet from the
bottom of the lake ; the next ten feet, and the highest fifteen feet.
Flumes through the surrounding masonry, also closed by gates
and gratings at their outward ends, will conduct the water to the
shaft gates. All the gates can, of course, be opened and closed
at pleasure. ^

The tunnel, as now constructed, will deliver, under a head of
two feet, 19,U00,OU0 gallons of water daily ; under a head of eight
feet, 38,000,000 gallons daily, and under a head of eighteen feet,
57,000,000 gallons daily. The velocities for the above quantities
will be one and four-tenths miles per hour, head being two feet ;
head being eight feet, the velocity will be two and three-tenths
miles per hour; and the head being eighteen feet, the velocity will
be four and two-tenths miles per hour. By these means it will be
competent to supply one million iieo2)le with lifty-seven gallons
each per day, Avith a head of eighteen feet. With regard to the
character of the work, the material met witli in the jirocess of
excavation has been stiff blue clay throughout, so that the antici-
pations of the contractors have, in this respect, been fulfilled.

The crib, since it was sunk and loaded, has been thoroughly
tested by violent storms, and, during the winter, by the moving
fields of ice. It withstood the shocks, both of the ice and the
storms, without injury, and the least movement of it, since it was
fairly loaded, has not been discovered.

MECHANICS AND USEFUL AKTS. 31

TUNNEL UNDER THE ENGLISH CHANNEL.

Mr. Hawksliaw has been engaged in making trial boi'ings with
a view to develop a project for a railway tunnel under the chan-
nel between Dover and Calais, and communicating on the Eng-
lish side with the Cliatham and Dover Railway, and on the
French side with- the Northern Railway of France. He proposes
to cai'ry on the excavations for the tunnel from both ends, and
also from shafts in the channel, at the top of which powerful en-
gines will be erected for pumping and winding up the excavated
material, and for supplying motive power to the machinery by
which the excavation is effected.

On the other hand, Mr. Geoi'ge Remington is of opinion that a
tunnel on the site jjroposed by Mr. Hawkshaw is impracticalile,
on account of the difficulty he anticipates in keeping down the
water in a chalk excavation of that magnitude. He therefore
proposes another line for the tunnel between Dungeness and
Cape Grisnez, which, entirely avoiding the chalk, passes through
the Wealden formation, consisting chiefly of strong clay. The
tunnel would be twenty-six miles in length from shore to shore.
On this route in mid-channel, there is an extensive shoal, with
only eleven feet of water upon it at low-water spring tides, where
Mr. Remington proposes to construct a shaft protected, by a
breakwater.

CHICAGO RIVER TUNNEL.

A tunnel has recently been commenced at Washington street,
on the south branch of the Chicago river. It is to consist of three
passage-ways, the centre one to be used by foot-passengers and
the two side ways to be used for vehicles. The middle passage
will be 15 feet high and about 10 feet wide, ei^ch of the outer pas-
sage-ways being 11 feet in width by 15 feet at the highest point.
The width of the river at Washington Street is about 180 feet,
while the whole length of the tunnel, after providing for a suita-
ble inclined plane at each entrance, will be about 9-45 feet. The
floor of the tunnel at the centre of the river will be about 32 feet
below low-water mark.

The tunnel is to be constructed by means of coifer-dams, which
are to be placed, with their pi'otections, up and down the river,
within a space, north and south, of not over 150 feet, and, east
and west, of not over 100 feet, so as to have a space of nearly 50
feet for the passage of vessels entirely unobstructed. Ui^on the
completion of the work, such portions of the dams as may remain
will be entirely removed, so as to leave the river as unoljstructed
as at present. The tunnel proper is to be formed of the most
perfect brick and stone masonry, backed with concrete, wliile the
floor of roadways will be neatly paved with Nicholson pavement.
The work is to be completed in March, 1868.

Should this latter work prove a success, we may look for the
general adoption of the tunnel instead of the bridge i)lan at all
our river crossings ; and, as a consequence, the absolute freedom

32 AVNUAI. OF SCIENTIFIC DISCOVERT.

of the rivor to sailiiifj oraft of all descriptions, thus avoid in";' (lie
almost intcrniinalilc d(days now caused b}' the constant swin<j:ing
of the various l)nd2;es during the season of navigation, as well as
the many accidents which are sure to result from our present
bridge system.

The longest tunnel in England is the Box Tunnel on the Great
Western Railwa}-, wliich is 9,080 feet long, 39 feet high, and 35

feet wide.

SAXD-rATCH TUIOfEL.

The miners working in the middle section of the Sand-Patch
Tunnel, on the Pittsburg and Connellsville Railroad, have met,
tluis piercing once more the great mountain l)arrier l)etween the
Ohio valley and the sea-board. Tiie Saiid-rateh Tunnel is 4,750
feet long, or 1,000 feet longer than the Alleghanj'-Mountain Tunnel
of the Pennsylvania Railroad. It was commenced some ten
years ago, is to accommodate a double track of rails all through,
being '22 fc(>t Avidc, and 19 feet high. The greater portion of it
goes through solid red sand-stone, not requiring any l)rick arch-
ing for that distance. The grade of the tunnel is 2,200 feet above
the level of the sea, or 1,500 feet higher than low-water mai"k of
the Ohio I'iver at Pittsburg.

TUB MOXT-CENIS TUNNEL.

It is estimated that the number of holes which have to be
drilled by the rock-boring machines in the IVIont-Cenis Tunnel,
before that work is completed, is about 1,600,000. The total
depth of all these holes when bored will amount to about 4,265,-
890 feet, which is 105 times the length of the tunnel. Nearly 13,-
000,000,000 IjIows will be struck by the perforators, to d() tiiis
"work. The entrance to the tunnel, on the French side, is 3,946
feet above the level of the sea, and its termination, on the Italian
side, 4,380 feet, so tliat the actual difference of level between the
two extremities is about 434 feet.

The total length of the Mont-Cenis Tunnel is 12,220 metres ; of
this, 7,977 remain to be made. Having been begun in 1858, and
with new methods and energy in 1863, 4,423.4 metres were fin-
ished on the first of April, 1«65 ; of which, 1,640 metres were ac-
complished by the old methods of tunnelling, and 2,777.4 bj^ the
new mechanical methods, since the commencement, of 1863 — 802
metres in 1863; 1,088 in 1864; and 337.4 in the first quarter of
1865. The rate of progi-ess in 1862 was 2.02 metres per day ; in
1864, 2.92 metres, and in 1865, thus far, 3.75. At the last rate, it
will take 5 2-3 years to complete the tunnel.

Air is compressed by w^ater-power outside, and is conveyed by
pipes into the excavation, where it gives motion to the chisels
that pei-forate the rock, forming cavities for the gunjiowder used
in blasting. Small pei'forators travel on a carriage, each of them
being a kind of horizontal air-pressure engine, the jjrolonged
piston-rod of which carries a jumper, that makes 250 strokes a
minute. The excess of pressure on each jumper, above that of
the air-spring which brings it back, is 216 lbs., thus bringing a
very considerable power into action.

MECHANICS AND USEFUL ARTS. 33

THE FRENCH CANAL AT SUEZ.

It is announced that in 1867 the long-projected canal through
the Istlimus of Suez, will be opened to the world. In this great
enterprise, the French have once more shown their extraordinary
control of persons of totally opposite characters and habits of life,
and have, moreover, exhibited the business faculty in a degree
rarely shown by other than Englishmen. There are now work-
ing at the canal nearly 19,000 men, of whom 8,000 are Euro-
peans, and the remainder Arabs, Egyptians, or Syrians. The
crews of the dredging-machines are often comjiosed of French-
men, Italians, Greeks, Germans, Egyptians, and Maltese ; and we
are assured that they are in no way inferior to the more homo-
geneous crews which are seen at home. The Orientals even ex-
hibit a zeal and ardor Avhich almost equal the activity of French-
men. The arrangements for the housing, feeding, and sanitary
welfare of the workmen are, seeminglj-, very complete. There
is free trade in provisions, and 1,490 traders have established
along the line of works, hotels, canteens, warehouses, and shops,
where almost everything can be obtained. The medical, postal,
and telegraphic services are under the control of the company.
At great expense, a water supj^ly has been obtained, which yields
2,000 cubic metres per day. The district is destitute of water-
courses, and this aiTangement was, therefore, of the highest im-
l^ortance. By these means, cholera and other maladies have been
warded off. From the measures taken by M. de Lessejis and his
colleagues, for the comfort and health of the workmen, we miglit
learn a lesson. In India, China, and the colonies, we have army
" stations," which are regularly occupied during certain seasons
of the year, and which are yet without proper house-room and
13ure water.

But beyond these things, the mechanical contrivances which
have been invented, and are now used, for the several different
kinds of work, are worth consideration. Conspicuous among
them are the dredging-machines. To cut a channel through a
certain piece of land, the plan adopted has been to dig by hand
until sufficient depth and width has been secured to float a dredg-
ing-barge, when the water has been let in, and the machine set
in motion. Instead of emptying the mud into another barge, to
be taken out to sea and there discharged, each dredge has affixed
to it a long spout, the upi^er end of which begins on the dredge
itself, as high as i^ossiblc, where it receives the earth raised by
the buckets. At the same time, pumps worked by the steam-
engine of the dredge raise a torrent of Avater which carries the
earth off bej'ond the bank, and spreads it over a wide surface.
In this country, where we are just now about to reverse our sys-
tem, and keep our rivers clear instead of tilling them with dejios-
its, a modification of this machine would be .of great service. By
its means we might at once deepen and clear the beds of our
rivers, and add materially to the fertility of the adjacent fields.
Few things are more fertilizing than what is called " wai"p," and
by the means thus pointed out, this could be obtained artificially.

34 AXNIJAL OF SCIENTIFIC DISCOVERY.

In mnny places in Eiifrlaiul, a plan not unlike that by which the
valley of tlie Kile is made fertile, is carried out. In Yorkshire,
for example, it is a regular practice to open the banks of the
Dutch river, and allow its turl)id waters, which contain nnich soil
in suspension, to spread over tlie ticdds. When the j^aj) is closcid,
and the water drawn off, a rich alluvial mud remains, on which
splendid crops are raised. The system of openin;^ the l)anks of
tiu! river is, however, awkward and expensive. Tlie Suez canal-
dredu:e does away with its necessity, and a])plies scienlitically
what is now obtained by a very clumsy system. — London Slur.

The i\Ialta "Observer," of a late date, says: "By reliable infor-
mation, recently received, we learn that the works of tln^ Isthmus of
Suez Canal are beinf>^ very actively carried forward by M. de Les-
seps. An averaj^e dejith of from seven to nine feet has been ob-
tained from I'ort Said, along the salt-water canal ; and the rest of
tlie distance to Suez is traversed temporarily by a fiesh-wat(u* one
about seven feet deep, connected with the other by means of locks
and powerl'ul pumps. As far as sixty stations the full width of
the projiosed ship-canal has been excavated to sixty metises ; but
from that point to the seventy-fit'th station and Ismalia, the width
is iiicom])lete. All that has been done is done well, and relleets
the highest credit on the science, skill, and persevering energy
of the French engineers. The real dillieulties of dredging in a
constantly dissolving sand are now commencing; but well in-
formed jjcrsons entertain but little doubt that these and all others
may be overcome by time and money."

FRITH OF FORTH BRIDGE.

Parliamentaiy sanction has been obtained for a bridge over the
Frith of Forth, of a magnitude which gives it great scientific inter-
est. It is to form part a of connecting link between the NortJi
Britis^h and Edinburgh and Glasgow Railways. Its total length
will be 11,755 feet, and it will be made up of the following spans,
commencing from the south shore : First, fourteen ojienings of
100 feet span, increasing in height from 65 to 77 feet above high-
water mark ; then six openings of 150 feet span, varying from 71
to 79 feet above high-water level ; and then six openings of 175
feet span, of which the height above high-water level varies from
76 to 83 feet. These are succeeded by fifteen oijeuings of 200 feet
span, and height increasing from 80 to 105 feet. Then come the
four great openings of 500 feet span, which are placed at a clear
height of 125 feet above high-water spi-ing tides. The height of
the in-idge then decreases, the large spans being followed bj^ two
openings of 200 feet, varying in height from 105 to 100 feet above
high water ; then four spans of 175 feet, decreasing from 102 to
96 feet in height ; then four openings of 150 feet span, varying in
height from 95 to 91 feet; and, lastly, seven openings of 100 feet
span. 97 to 92 feet in height. The piers occupy 1,005 feet in
aggregate width. The main girders are to be on the lattice
principle, built on shore, floated to their position, and raised by
hydraulic poAver. The total cost is estimated at £476,543. —
Engineering, Jan. 5, 1866.

MECHANICS AND USEFUL AUTS. 35

WASHINGTON AQUEDUCT.

At a meeting held December 6, 1866, Mr. Edward C. Pickering
called the attention of the Massachusetts Institute of Technology
to one of the greatest of American engineering works, and, at the
same time, one of the least known, viz., the aqueduct by which
the city of Washington is supplied with water.

The plan accepted by Congress was to ei*ect a dam across the
great falls of the Potomac, conducting the water about thirteen
miles through two reservoirs to the city. Gen. Meigs, who had
the work in charge, instead of reports, prepared photographs of the
working drawings and of the aqueduct itself; a set of these rare
photographs he exhibited and explained to the Institute. The
supply thus obtained for the city of Washington is 67,000,000 gal-
lons daily, twice as much as the Croton, and five and a half times
as much as the Cochituate supply. The greatest engineerino-
work in the Cabin John branch is the bridge over Cabin John
Creek, which has one stone arch with a span of 220 feet, makino-
the largest arch now in existence ; the Chester ai-ch beino- only
200 feet, London Bridge 152, Neuilly 128, and the Rialto 99 feet.
When the centre scaffolding was removed the arch did not settle,
the key-stone having been set in winter and the centre struck in
summer. Other great arches have settled more or less, according
to the excellence of the workmanshii? of the arch and centre.

From the distributing reservoir the water is conveyed in two
30-inch pipes. There were two streams to be crossed, College
Branch and Rock Creeks. In spanning these creeks the structi^-e
is remarkable, not only for size, but for the ingenious principle
of construction. Instead of building a bridge and laying pipes
on it, the pipes themselves were cast in the form of an arch, and
constitute the bridge. The Rock Creek bridge has a span of 200
feet, with two 48-inch pipes ; the College Branch bridge has a
span of 120 feet, with two 30-inch i)ipes. The arch is so strong
over the Rock Creek that a roadway is placed upon it, continuing
Pennsylvania Avenue to Georgetown. The pipes were at first
lined with wood. The diurnal rise and fall of the bridge is about
two inches ; this constant motion produced slight leakage from
droppings ; the wooden lining was then taken out, as it was shown
there was no danger of freezing, and now there is no leakage, the
pipes remaining at the temperature of the water.

It was commenced in 1853 and finished in 1863.

SUSPENSION BRIDGE AT CINCINNATI, OHIO.

Another gi-eat triumph of American engineering is the suspen-
sion bridge over the Ohio River at Cincinnati, from Front Street,
in that city, to Second Street, Covington, Ky. It is said to be
the longest single-span bridge in the world. Its cost was about
$2,000,000. It is strong, ornamental, and affords an easy road
of communication between the States. Railroad tracks are to be
laid over its span. The following are its dimensions, &c. :

36 ANNUAL OF SCIENTIFIC DISCOVERY.

Length of main span from centre to centre of towers, 1,057 feet.
Leni^th of each land span, 281 feet.

Total k-n-^'th of bridge, including approaches from Front Street in Cincinnati
and Second Street in Covington, 'l,'1.^2 feet.

Height of towers from foundation, without turrets, 200 feet.

Height of turrets, 30 feet.

Height of bridge above low water, 100 feet.

AViilth of bridge in the clear, 30 feet.

Number of cables, 2.

Diameter of cables, 12.-} inches.

Amount of wire in tho cables, 1,000,000 pounds.

Strength of the structure, 10,800 tons.

Deflection of cables, 88 feet.

Masonry in each tower, 32,000 perches.

Jhisunry in each anchorage, 13, 000 perches.

Masonry, total amount, 1)0,000 perches.

Towers at base, 80 by .'>2 feet.

Towers at top, 74 by 40 foot.

Strands in each cable, 7.

AVires in each strand, 740.

Wires in cables, total, 10,3G0.

IVeight of wire, "lOO tons.

Foot of lumber, «iOO,000.

GREAT VIADUCTS.

At a mcotin.!^ of the Society of Engineers, in January, 18GG, a
pajit'i- -was read by i\Ir. W. II. INIill.s, on the Cralgnllacliie Viadiiet.

Thi.s via(hict "vvas construct(.'d lor the puri)ose of carrying llie
Moraysliire Railway over the River Spey, at Craigelhiehie, Banft-
pliirt',' tiie engineers being Mr. Samuel (M. Inst. C. E.) and the
auliior. It consisted of tiu'ee spans of o7 feet each on the north
bank, and one si)an of l'DO feet over the main channel of the river;
ordinary boiler-plate girders constituting the former, and the lat-
ter being of wrought-iron on the lattice principle. The piers and
abutnu'uts Avere of solid ashlar masonry, and the works were ar-
ranged for a single line of railway. It appeared that tlie excava-
tion for the foundations was commenced in May, 1862, and that
the viaduct was opened for public tralli(! in July, 1863. The total
cost had amounted to £1l',1[)'J, or equal to £29 10s. per lincsal foot.

A paper was also read at the same meeting !)y Mr. Ridley, giv-
ing some details concerning the Grand River Viaduct, Mauritius
Railway.

It was stated that the length of this viaduct, from almtment to
abutment, Avas 620 feet, and that this distan<;e was diviihnl into
five openings of 116 feet each in the clear. The height from the
level of the rails to the surfixce of the water w^as 129 feet 9 inches.
Each \)WY was composed of two cast-iron cylindei-s, each ten feet
in diameter, resting upon masonry foundations, and filled with
concrete ; the works being for a single line of railway.

GREAT BRIDGES.

The Victoria Bridge over the St. Lawrence, at Montreal, has a
total length of one and three-quarters miles, and a length of iron
tubing of one and one-quarter miles, with 25 spans, one of 330

MECHANICS AND USEFUL AKTS. 37

feet and the rest of 242 feet, witli a headway of 60 feet. The
Britannia Bridge over the Menai Straits is 1,487 feet long with-
out the abutments, with two spans of 230 feet each, one of 458
feet 8 inches, and one of 459 feet ; and the Saltash Bridge 468 feet.
The Forth Bridge has a lengtli of 10,550 feet; and the Severn
Bridge nearly 12,000 feet. The bridge of the Hartford, Spring-
field and New Ilaven Railroad, over the Connecticut, at Ware-
house Point, replaces a wooden structure on stone jjiers, and was
built on the old piers with the addition of several new ones in tlie
same line, so that the present structure occupies the exact site of
the former one ; and during the seven months of its construction
no delay of trains was caused by the work. This is remarkable
when the magnitude of the work is considered. The bridge is
l,524i feet in length, composed of 624 tons of wrought-iron,
the iiooring only being of wood. In its construction, 175,000,
rivets were used. The cost was $264,784.63, and it is capable of
bearing a strain of two and a half tons to the foot. I'he iron-
work was made in England, by Fairbairu & Co. of Manchester,
and the London Engineering and Iron Ship-Building Company.
The plans and designs were by James Laurie, Civil Engineer, of
Hartford, Conn. — Scientific American.

STEEL BRIDGES.

At a late meeting of the Literary and Philosophical Society,
Mr. S. B. Worthington, C. E., stated that he had lately con-
structed a swing bridge for carrying a i-ailway over the Sankey
Canal, in which the girders were made of Bessemer steel plate.
The object of using steel instead of wrought-iron was to reduce the
weight of the girders ; these are four in number, about 56 feet
long, with bearings varying from 30 to 40 feet, and 2 feet deep.
They wei'e manufactured from steel tubes made by the Bolton
Steel and Iron Company ; and were tested with loads of a ton to
tlie foot, or more than double the weight which they could possi-
bly be called upon to bear. The deflection varied from one-half
to one inch, according to the length of the girder, and there was
no permanent set on removal of the testing load. The plates
used varied from one-quarter to seven-sixteenths of an inch in
thickness ; and the average tensile strength of a considerai^le
number of plates tested was upwards of 36 tons to a square inch.
The weight of the girders was about five-eighths of the weight
which they would have been if wrought-iron had been used.

CONCRETE BLOCKS FOR BUILDING.

An ingenious application of the well-known process of mould-
ing blocks of couereto for building purposes was patented some
time back. The inventor, a Mr. Tall, jDroposes to erect walls,
houses, and other structures, by literally casting them of concrete,
in the place they are intended to occupy. An ordinary concrete
foundation is first laid, and ui^on the foundation horizontal frames,
constructed of boards lined with zinc or other metal, are set up
on edge, so as to form a kind of trough for receiving the concrete.
4

38 ANNUAL OF SCIENTIFIC DISCOVERY.

By tlie insertion of suitable cores, holes for the insertion of the
joists, or for other puriJoses, may be moulded in the concrete as
the work proceeds.

LIME CONCRETE IN CONSTRUCTIONS.

Mr. F. Ingle conimunioatod to the British Association, in 1806,
a ]Kiper in which he pointed out what he considered a radical
defect of concrete formed from lime as ordinarily used, viz., that
by the action of fire it becomes reconverted into lime, which,
when the water from the engines is brought to bear ui)on it,
expantls greatly, and forces out the walls, to the destruction of
the Ijuildiiig. lie advocated the use of a concrete formed from
g}'2^^"'i'> wliich is not liable to this defect. The gypsum, which
is of a coarse and inexpensive character, is formed into j)lasti'r of
Paris by roasting, and mixed with a pecuhar kind of clay found
in counection with the beds of gypsum.

HYDRAULIC CEMENTS.

M. Fremy communicated, in May, 1805, an important paper on
this subject to the French Academj' of Sciences. Vicat assumed
the formation of a douljle-silieate of alumina and lime, wliich, by
absorbing water, was the cause of the setting of hydrauHc ce-
ments, and this view seemed to be confirmed by finding in the
calcined cements a silicate which formed a gelatinous precipitate
witli an acid, whicli silicate did not pre-exist in tin; stone before
calcination. MM. llivot and Chatonay suggested that the calci-
nation of the argillaceous limestone gave rise to an aluminate of
lime having the formula Al- O" 3 Ca O, and to a silicate of lime
represented by Si O-^ 3 Ca O, which salts brought into contact
with water form hydrates, each with six equivalents of water, and
thus cause the setting.

The result of the experiments of M. Fremy is, that the setting
of cements is due to two difi'erent chemical actions : first, to the
hydration of the aluminates of lime ; and secondly, to a puzzu-
olanic action, in which the hydrates of lime combine with the
silicates of lime and alumina. He found that alumina is even a
better flux for lime than silica, and he suggests that the very
basic compoiuids of these two substances — those, for instance,
containing from 80 to 90 per cent, of lime — may be useful in the
iron furnace, owing to their disposition to absorb sulphur and
phosphorus, and thus free the metal from these noxious impuri-
ties. He also finds that no substance is capable of acting as a
puzzuolana except the simple or double silicates of lime, con-
taining only from 30 to 40 per cent, of silica, and sufficiently
basic to form a gelatinous precipitate with acid.

INSOLUBLE SILICATE.

M. Ch. Guerin called the attention of the French Academy to
a new method of obtaining, by a cold process, a silicate com-
pletel}' insoluble, which can be ajjplied either as an external coat-
ing, as in the case of glass or iron, or made to penetrate throui^h
the interior of the substance, as for the preservation of wood and

MECHANICS AND USEFUL ARTS. 39

other vegetable mattevs. The process is very simple : a thin
coating of slaked lime made into paste with water, or whitewash,
is laid on the object to be silicatized, and, when this has been al-
lowed to dry, silicate of potash is applied over the coating ; the
effect, it is asserted, being that all the portions touched by the
solution of potash become completely insoluble, and of very great
adherence. In order to obtain adi insoluble silicate in the interior
of a substance, all that is necessary is to impregnate it by im-
mersing it in whitewash or lime-water, and, when it is dry, to
steep it in a solution of the silicate of potash.

By this means it is proposed to prevent the decomposition of
vegetable substances by petrifying them ; also, to protect po-
rous building-stones and brick against air and damp; iron, by a
coating of jjaper, pulp, or other finely-divided woody matter,
mixed with slaked lime.

Again, letters, characters, or any other device, can be traced
with the silicate on any surface spread with lime ; and those y>ov-
tions touched by the silicate will alone adhere and become insolu-
ble. Or, if they be traced with a solution of gum arable, and the
whole be washed over with the silicate, the parts protected by the
gum can be washed off, the rest remaining in relief, as the let-
ters, etc., do in the first place.

The process seems to be substantially the same as the Eng-
lish process known as Ransome's. — Scientific American.

A NEW CEMENT.

A late number of the " London Engineer" announces a new
cement of great value, which is introduced under the euphonious
title, " The zojiissa iron cement," which, it is claimed, is capable
of joining any two solid substances, however dissimilar. Wood,
brick, iron, stone, or glass, can be inseparably united with equal
facility. A series of experiments, witnessed by the "Engineer,"
gave the following results : —

Plates of glass were firmly joined, edge to edge ; ordinary
bottles stuck upon the wall resisted all atteiiipts at sepai-ation, till
the stone yielded. Chami?agne bottles, cemented laottom to bot-
tom, sustained a weight of 250 jjounds. Two bricks remained
joined under a tension of 325 pounds, till the brick itself frac-
tured, but the cement remained firm. Brick-work cemented with
this has the solidity of a granite slab.

With paper treated with this preparation in solution, the in-
ventor has made air and water-tiglit tubes, ammunition cases,
coffins, and even constructed a house, one story and a half in
height, perfectly wind and water tight, which he has now on
exhibition.

Of the constitution of this cement, or the expense of manufac-
turing it, the "Engineer" makes no intimation.

HARD HYDRAULIC CEMENT.

The following receipt is given for a cement, which, it is said, has
been used with gi'eat success in covering terraces, lining basins,
soldering stones, etc., and everywhere resists the filtration of

40 ANNUAL OF SCIENTIFIC DISCOVERY.

water; it is so havcl tliat it scratches iron. It is formed of ninety-
three parts of well-l)Urne(l l)riek, anil seven i)arts of litharge, made
plastic with linseed oil. Tl>c l^rick and litharge are i)ulverized ; the
latter must always l)e reduced to a very line powder; they are
mixed together, and enongh of linseed oil atlded. It is then ap-
plied in the manner of jjlaster, the body that is to be covered
being i)revionsly wet witli a siv.)nge. Tins iK'ccantion is indis-
pensalile, otherwise the oil would (ilt<'r through the body and
prevent the mastie from acquiring the desired hardness. When
it is extended over a large surface, it sometimes happens to have
flaws iu it, which must be filled up with a fresh quantity of the
cemi-nt. In three or four days it becomes firm. If its advan-
tages have not l)een overrated it must be a very excellent cement
for making the joints of aquaria water-tight. — Brugijisfs Circular^
1801'..

At the meeting of the Paris Academy of the 4th of December,
18Go, II. St. Claire Dt'ville showed that magn(!sia, kept for some
weeks in pure water, sealed up so that the air is excluded, com-
bines with water, and forms a hard and comjjact, crystalline,
translucent suljstanee, consisting of magnesia GS.S, water oi.7, or
a simple hydratt! of magnesia. lie lias made copies of medals,
like those of plaster, from magnesia thus hardened under water.
Balard's magnesia, calcined at a red heat, he says, has hydraidie
qualities whicli are manifested with a rapidity that is admirable,
though, when calcined at a white heat, tins property is almost en-
tirely lost. A mixture of powdered chalk, or marble and magne-
sia in equal parts, furnishes with water a ])aste which is slightly
l)lastic, but which, after being some time in water, affords prod-
ucts of very great solidity; and he pnjposes to make busts of arti-
ficial marble i'rom the mixture. Plaster mixed with the magne-
sia diminishes the hydraulic ])roperties. On calcining dolomites
rich in magnesia, the same rule as to hydraulic j)roperties is I'c-
marked iu regard to tempt'rature, the higher the heat the less the
hydraulic projierties. lie thus believes that this suljstance, now
so cheaj^ly and abundantly furnished by M. Balard's processes,
will come into extensive use in subaqueous structures. — Les
Maudes, Bee. 7, IBGo.

A cement, capable of uniting into a solid mass stones, jDebbles,
&c.,so as to form artificial pudding-stone, conglomerates, &c., of
extraordinary strength and tenacit\% impervious to moisture, and
capable of being moulded into statues, bas reliefs, &c., ma}'^ be
made by finely triturating iron sponge, and mixing it with sand
which has been moistened with slightly acidulated water. The
iron is oxidiziid at the expense of the water, and the silex forms
with the oxide silicate of iron, which possesses a very great
tenacity, and is not affected by atmospheric changes, nor even by
acid or alkaline liquids at a boiling temiDeraturc. — Intelleclual
Observer, Feb., ISGG.

CEMENT WITU A GYPSUM BASIS.

The plaster is first burned in the usual way, in an ai^iirojiriate
fui-uace, to diive off the water ; after this it is broken into small

jreCnANICS AND USEFUL AKTS. 41

fragments, which are immersed in a solution of alkaline silicate,
containing an alkaline carbonate. Tlie solution which answers
best is composed of silicate of potash, containing a sullieient
number of equivalents of carbonate of potash to avoid the pre-
cipitation of the silica, in the following proportions : 0.880 kilog.
(1.94 lbs.) of silicate of potash containing 0.255 kilog. (.56 lb.)
of carbonate of potash, in 4.54 litres (a gallon) of water, a
solution having a specific gravity of 1,200, but which may vary
according to the use for which the cement is intended. As, for
example, it can be employed of the strength above indicated in a
great many cases where the best quality is required ; and, if an
ordiuai-y cement is only necessary, it can be diluted with two
parts of water to one of the solution. If a cement be required
to harden slowly, sulphate of potash may be added to the car-
bonate, so that the indurating action of the silica upon the plaster
may thus be varied at pleasure. After having left the plaster
steeijed in the solution for twenty-four hours or so, it is taken out
and left to drain in a compact mass, in order that the diffusion of
the solution through the plaster may take place more effectually ;
the cement is then taken back to the furnace, and reheated to
150° or 250° C. (302° to 482° Fahr.) to drive off all the water,
after which it is ground to powder, and can be colored to any
desired hue by mixing with a jjigment. — London Builder, No.
1210.

NEW MORTAR.

The mortar used by the Romans has, in the course of ages, set
so strongly as to be equal in hardness to the stones it was used to
cement, and its analysis shows that this is due to the abundant
formation of silicate of lime throughout the mass. Modern mor-
tar, on the contraiy, usually hardens slowly, cracks while harden-
ing, has but little adhesion, and its useful effect is simply as a bed
for the i^roper support of the stone or brick ujjon its whole
surface, and the consequent distribution of the pressures properly
over the sustaining masses. Analysis shows little or no formation
of silicates, and the carbonate of the quicklime (for it absorbs
carbonic acid itself very slowly) is soluble in the rain to which
it is exposed, and rapidly dissolves out. Dr. Artus proposes a
method of preparation by which the process of silication is much
ftivored ; by which, it is said, a mortar may be jjrepared which
becomes as hard as cement, does not crack in setting, and may be
used as a hydraulic cement under water. This process is as
follows : Take good slacked lime and mix it with the utmost care
with finely sifted sand ; mix the sand thus prepared with finely
powdered quicklime, and stir the mixtiire thoroughly ; during the
process the mass heats, and may then be emjjloyed as mortar.
Of course, the mixture must be made just as it is to be used.
One part of good slacked lime was mixed with three parts of
sand, and to this was added three-fourths of its weight of finely
powdered quicklime. The mortar thus made was used in a
foundation wall, and in four daj'S had become so hard that a piece
of sharp iron would not attack it. In two months it had become
as hard as the stones of the wall.
4*

42 ANNUAL OF SCIENTIFIC DISCOVEKT.

It niisfht be worlli Avliile to try this for laying iJio Ijricks of our
chimiu'y.s, which are so rapidly destroyed and rendered daniijerous
by the gases from burning anthracite. — Journal of the Fmaldin
Institute, July, 18G6.

S. r. EUGGLES'S DYXAMOMETER.

At the meeting of the American Acadeni}' of Arts and Sciences,
held January 9, 18<)G, Prof. Charles W. Eliot exhibited and
deseril)ed a \w\y kind of dynamometer, invented by Mr. S. P.
lluggles of Boston :

'* This new and admirable invention accomplishes two objects;
first, it measures the exact amount of power whieii is being
consumed in driving a single maeiiine, or any nunilter of ma-
chines, at any instant of time, indicating every change in the force
recjuired, as the work done by the machines varies from instant to
in^tant; secondly, the apparatus adds up and i-egisters the total
amount of power whicli has Ijeen used by any machine!, or set of
machines, lUning a da\', a week, a month, or any desii-ed time.
Tlu! apparatus may be thus desci'ibed. The pulley from which
the power is taken, is attaciied to tiie shaft by the intervention of
a sj)iral sjiring. One end of tiiis spring is secured to the sliaft,
and the otiier end to the hub of the pulley. The lateral motion
of the ])uliey upon the shaft is previ-nted by a colhir on cither
side of the ])ulley. On the inside of the huij is cut a screw of
al>out three-ineli jMteh, that is, a screw which makes a comjjlete
turn within a distance of about three inches measun^d on tiie axis
of the hub. A rectangular slot is cut out of tiiat part of the sliaft
which lies within the hul) of the pulley, and in this slot slijis back-
wards or fcn'wards a piece of metal whicli jn-ecisely tits the slot.
From each side of this small piece of metal, there i^rojects beyond
the surface of the shaft a small portion of the male screw which
exactly fits into the screw cut in the interior of the hul) of the
pulley. If there be no resistance at all to the motion of the pul-
ley, shaft, spring, and pulley will all start together, and I'cvolve
together. But if a resistance be offered to the motion of the
pulli'V, the shaft, and with it the piece of metal which slips in the
slot, will start first, and the pulley will move only when the strain
caused by the twisting of the spring is sufficient to overcome the
resistance a])plied to the circumference of the pulley. But if the
piece of metal in the slot begins to turn while the hub of the ])ul-
ley is stationary, the piece must move laterally within the slot,
being forced by the screw. If the pulley starts a quarter of a turn
later than the shaft, the piece will move laterally three-quarters
of an inch ; if the pulley st;irts a half a turn later than the shaft,
the piece Avill move laterally an inch and a half. The lateral
motion of the piece in the slot is proportional to the retai'dation
of the pulley, and this retardation is proportional to the strain
upon the belt which passes over the pulley, and convej-s the power
to be used. To the movable piece in the slot is connected a small
round rod, which runs out through the centre of the main shaft
and i^rojects some little distance beyond it. On the end of this
rod is a circular rack of teeth, in which plays a pinion, on whose

MECHANICS AND USEFUL ARTS. 43

shaft is a hand moving ovei* a dial-plate. By appljiug strains,
measured by standard scales, to the belt which passes over the
pulley, — as a strain often pounds, fifty pounds, one hundred
pounds, — it is easy to graduate tlie dial-plate into pounds, so that
the number of pounds of strain upon the belt may be read off at
any instant by a mere inspection of the dial. The mode of oper-
ation of this part of the apparatus is then as follows : When no
power is being conveyed from the pulley, shaft and pulley start
simultaneous!}' ; there is no lateral motion of the piece within the
slot and its connected rod, and the hand on the dial points to zero.
But the moment tliat power begins to be expended in driving- the
machinery, the strain upon the belt Avill be lirst felt by the spring
which connects the pulley to the main shaft, and the spring will
yield in proportion to the strain ; the effect is to let the shaft make
a small part of a revolution in the hub of the pulley before the
pulley begins to turn and keep pace with the shaft ; the rod within
the end of the shaft is thus drawn in a little, the hand moves over
the dial-plate, and points to the exact numl^er of pounds of power
which the belt is conveying from the pulley at the instant of
observation.

The registering of the total amount of jDower delivered from
the palley is effected by means of two small belts running over
the round rod, which projects beyond the end of the main shaft
and carries the index-hand above described. These two small
belts communicate the motion of the shaft to two jiarallel and
equal wheels, one of which bears a dial-plate, and the other an
index-hand which moves over the dial-plate. When there is no
sti-ain upon the main belt going over the pulley, the two wheels
revolve at the same rate, neither gaining upon the other, and
the hand remains constantly over the same figure on the dial-
plate ; but Avhen a strain is put upon the belt, and the round rod
moves laterally, as above described, the lateral motion brings a
conical enlargement of the rod under the little belt which moves
the wheel bearing the dial. The dial-wheel now goes faster than
the wheel carrying the hand, and begins to count up the power
used. The greater the latei-al motion of the rod, or, in other
words, the greater the power transmitted to the working-ma-
chines, the larger the diameter of the cone which comes under
the belt of the dial-wheel, and the greater the gain of the dial
npon the hand. The wheels of both dial and hand are constantly
revolving in the direction opposite to that of the motion of the
hands of a watch. The belt of the hand-wheel runs always upon
the rod where its diameter is constant, and as the rod moves later-
ally under the little belts, guides are necessary to keep the belts
themselves from moving laterally also. The proportions of the
cones on the rod and of the two wheels which carry the dial and
the hand, can lie so adjusted as to make a difference of one com-
plete revolution between the motions of the iiands and of the dial,
indicating a delivery of ten thousand foot-pounds, or of ten million,
or of any other convenient number, and by a system of gearing
analogous to that used in gas-metres, any desired amount of
power could be consecutively registered. It is obvious that the

44 ANNUAL OP SCir.NTinC DISCOVERY.

registorin<x apparatus takes account of both the strain and the
speed, while tlie simple index lirst described measures only the
strain.

This instrument is at once eleji^ant in desio^n, simple and there-
fore eheaj) in its construction, easily verilieil and proved at any
moment when in operation, and of very easy application to any
machine, or set of machines, driven by hired poAver, whether the
power used be constant or varial)le in amount. The instrument
admits of a great variety of forms ; the one described above is
meant for the end of a shaft ; anotlier form is so arranged as to
be attached at any part of a running shaft, while in the propor-
tions and dimiMisions of the several parts there would be the same
variety as in conunon scales, which are large or small, coarse or
fine, according as they are meant to wa^igh coal or pills, hay or
coin. The instrument meets a pressing want. Tea and sugar
are sold by the pound, gas by the thousand feet, cloth by the yard,
but steam-i)ower and steam and air engines are sold by guess-
work, or liy rougli and uncertain rules, on whose api>lication
buyer and seller can seldom agree.

ileri'after steam-power can be sold by the thousand or million
fo()t-])ounds.

Mr. lluggles does not jiatent his valuable invention.

RUGGLES'S SHAFT-COUPLING.

There are some mechanical powers, which, because of not being
of universal or general applii'ation, are seldom uschI and recog-
niztMl, but which are of a most im])ortant and valual)le character.
Such is the dilVerential screw, which is rarely used, but which, in
certain instances, is the strongest grip known in mechanics. Tliis
has been a])])lied in the above improvement very effectively.

It is a dillerential screw-ljolt having two threads, that on the
upper poi-tion being ten to the inch, and that on the lower part
nine to the inch. The head of the bolt is six-sided, and is flush
with the surface of the box. It is seated in a circular recess,
which is large enough to receive on the end a cylindrical or
socket-wrench. Threads corresponding with those on the two
portions of the bolt are taliped in the boxes made to fit the shaft.

The above is sufficient to explain to any practical man the
operation of this device. It Avill readily be seen that a few turns
of the screw will be sufficient to clamp the shaft-ends in a grip,
the power of which is limited only by the strength of the mate-
rial. Two steady-pins are inserted in the shaft, and jn-oject into
holes drilled into the coupling-boxes, to provide against negli-
gence in setting up the screw, thereby allowing the shaft to turn.

This is evidently a valuable and efficient coupling. It presents
no nuts or bolt-heads to catch belts or clothing, obviates the neces-
sity of keys and splining, cannot get out of order, and presents a
neat appearance, when turned and polished looking nearly like
the enlargement of the shaft.

This invention was patented April 24, 18G6, by S. P. Ruggles,
Boston, Mass. — Scientific American.

MECHANICS AND USEFUL ARTS. 45

WICKERSHAM'S NAIL MACHINE.

Before the year 1807, nail-making was a very slow and labori-
ous process, each nail being cut from the bar by shears, and then
screwed into a vice where the head was struck on by a hammer.

About this time, Mr. Jesse Reed, of Massachusetts, invented a
machine by which the cutting and heading of tlie nails were
performed by one continuous operation in the same machine.
This Reed INIachine, though it cut but one nail at a time, has, with
but slight alteration, been the only nail-machine in use up to the

present date.

By a reasonable estimate, Mr. Reed, by his machme, reduced
the cost of cutting and heading nails to one-tenth that of the
process used befoT-e his invention, and those who availed them-
selves of rights under his patent have thereby realized large

fortunes. -.^r•^^^

The machine now brought to public notice by Mr. Wdliam
Wickersham cuts the nail with head ready formed at less than
one-tenth of the cost by the machines now in use, and at the
same time it produces a nail which, from being pointed like a
chisel, and gradually tapered its whole length, is much better for
use, being more easily driven and holding much more firmly, as
it breakslhe grain of the wood so little that it clings tightly and
firmly the whole length of the nail.

The universal plan has hitherto been to make the plate from
which the nails are cut wide enough for the length of the nail,
and then commence cutting from one end, and continuing the
operation until it is all cut into nails, the machine cutting only
one at a time.

In the Wickersham Machine a sheet of metal from 20 to 25
inches square is placed, and a series of nails cut from its edge at
each stroke of the knives. To do this, there are two series of
cutters, viz., bed and moving cutters, so arranged that by shifting
the nail-sheet laterally the distance equal to the length of two
nails, each time a series of nails is cut, the nails being alternately
reversed as to heads and points. The motions of the machine
are reduced to their greatest simplicity, there being only three
motions, viz., the crank-motion of the cutter jaw, the cam-motion
for shifting the nail-plate, and the feed-motion which moves the
nail-sheet 'towards the cutters each time it is shifted and a series
of nails cut.

In cutting half-inch patent brads or shoe-nails from a twenty-
inch plate, "there is a series of 40 nails cut at each stroke of the
knives, or 160 per second, the machine driving the knives four
times per second; of patent brads from three-eighths to two
inches long, and shoe-nails of all sizes, one machine will cut
3,600 Uds. per day. Of the larger size nails, say six to twelve-
penny nails, one machine will cut 5,000 lbs., and of ship-spikes,
of one quarter to three-quarter lbs. each, one machine will cut
25,000 lbs. per day often hours.

From the best authority it appears that there are 3,000,000 kegs
of nails made annually in the United States; of these three-

46 ANNUAL OF SCIENTIFIC DISCOVERY.

tenths are finisliin;^ nails ; besides, there are 200 to 300 tons of
shoe-nails, and about 1,500 tons of ship-spikes and nails made
of yellow metal.

ON THE UTILIZATION OF PEAT AS FUEL.

An invention of considerable practical importance for the con-
densing and moulding of peat for use as fuel, has recently been
brought to j)uhlic notice liy ]\Ir. T. II. Lcavitt. Tn a i)amphlet
compiled by liim, and pul)lishcd in Boston in IbGG, the Avhole sub-
ject of peat fuel is thoroughly ti'eated, showing its economy as a
sul)Stituti! for wood and coal, especially where fuel is required in
large quantities.

Tiie discoveries of the more imi)ortant uses of peat are recent,
though its use, in an imperl'cctly prej)ared form, has for a long
time been known in various parts of Europe and in this country.
It is found to coutaiii a ricii supply of the carboniferous oil of
whirii our common illuminating gas is made, and is pronounced
equal in that respect, pound for pound, to gas coal. It also pro-
duces I'osin and some i)araffin. Its analysis shows but five per
cent, of ashes, and ,')') of carbon.

The experiments made last year on some of the railroads in
Great Britain prove very conclusively that peat can be advan-
tageously substituted for coal on the locomotive. That it is also
actually ecjual, if not really sujjcrior, to tiie best charcoal itself
for smelting iron ore and for puddling iron, has been demon-
strated with equal certainty. The iron thus produced is tougher,
finer, more malleable, freer from flaws, than any other. By this
use of peat, iron from Englisli mines of admitted inferiority to
the famous Old Hill mine in Salislniry, Connecticut, and the
equally celebrated Swedish charcoal iron, has been produced of a
quality equal to either.

In all cases where it has been properly prepared, it is found to
burn equally well in a coal-stove, wood-stove, or fire-place, and to
make a very pleasant fire, with more flame than coal makes ; and
it leaves no cinders. Its freedom fi-om sulphur renders it far less
destructive than anthracite coal to the iron bars of the grate. A
stove lasts much longer with peat. This freedom from sulphur, a
point of the first importance in the selection of fuel for the reduc-
tion of iron ores, is also a weighty consideration with the railroad
men, whose experiences with the destructible action of anthracite
on their engines have made them shy of that fuel.

It comes in good time. Coal has been unreasonably expen-
sive ; and a good article of peat, that can be used in the stove,
the grate, the old "fire-place," or under a steam boiler, at prices
far below those for coal, after making every allowance for the rel-
ative capacity of the two articles, will be likely to be generally
used. Peat keeps a live coal till all is consumed, and is said to be
superior for cooking. Its importance in mechanic arts is likely to
be extensive. It already finds favor for the process of melting
gold ; it is pronounced a success in working steel ; while its use
in annealing is proved by the superiority of the wire made by
means of peat.

MECHANICS AND USEFUL ARTS. 47

^ The paper read last year before the British Association by Civil
Engineer Clark, of London, contains important fticts relative to
peat.^ A large establishment is engaged in making it in England,
and its trial on two of the British railways proved that it main-
tained a higher and better head of steam than coal did, that better
time was made, and that, pound for pound, it was a saving both
of time and money to use peat in locomotives.

The machine of which we have spoken may be worked by
steam or other power. It receives the crude peat just as it is
taken from the bog, condenses it, and in a very few minutes de-
livers it in the form of bricks, which may then be exposed in the
open air or under shelter, to dry or cure.

There are vast beds of peat in New England and New York,
and it behooves our farmers to avail themselves of it, and thus,
while turning " uniirofitable " land to account, preserve their
forests, which are now rapidly used up for fuel, till better uses can
be found for them.

IMPROVED MACHINERY FOR WORKING GOLD AND SILVER ORES.

Messrs. Whelpley and Storer, of the Boston Milling and Manu-
facturing Company, have introduced machinery for the pulveriza-
tion of gold and silver ores, in which mechanical principles are
applied that have never before been employed for such a purpose.

The ores are broken, in the first instance, by the rapid
movement of a circular iron table, a mass of metal 3h feet in
diameter, weighing 800 pounds, making 1,025 turns per minute.
The table itself forms the bottom of a cast-iron tub, 18 inches
in depth, of which the sides are grated, or perforated with small
openings. The entire structure, except the upright shafts upon
which the table revolves, is of cast-iron, the wearing parts
being of what is called Franklinite iron, which is so hard that
it cuts glass. The upper surface of the whirling- table, or bot-
tom of the tub, is furnished near its circumference with several
blocks, called cutting or splintering blocks, also of Franklinite.

The material to be broken, being fed into the tub through the
hopper, drops until its lowest point receives a shivering blow
from the upper edge of the rapidly-revolving blocks, by which it
is constantly thrown upwaixl and outward against the sides of the
cylinder, being i-eflected back upon the blades until it is-suificiently
comminuted to pass through the perforations into the surroundhig
box or chamber.

The weight of the table, with its case, shaft, frame, cutters,
etc., complete, and packed ready for transportation, is about
3,600 pounds.

An average of twelve-horse power is allowed, in practice, for
the full work of a whirling-table.

The whirling-table is more rapid in its action than any other
machinery for cutting or breaking. It is callable of reducing
more than 200 tons of ordinary quartz, in pieces from three or
four inches in diameter, to coarse gravel size, in twenty-four
hours. It lias reduced eighteen tons of quartz into gravel, in one
houi-, through three-quarter-inch holes.

48 ANNUAL OF SCIENTIFIC DISCOVERY.

Tlio broken fraq'mcnts ai"e swept tlirou£;:li tlie holes or f^^ratin^^
of the tub the instant they arc proclucetl, by the immediate aetioii
of the advanoinf^ faces of the cutting lilades. Thus it liappens
that no part of the work of reduction is performed l)j the sides of
the tub, but solely by the l)lades. The ta1)le is maile strong
enough to bear 1,500 revolutions jier minute, without rupture;
but any speed above 1,02.> turns per minute is wasteful of steam
power, and does not nnieh increase the yield.

In general, the higher the velocity of the whirling-table, the
less it wears, according to tlie amount of work done.

The whirling-table is intended to reduce oi-es, from a diameter
from three to six inches, to the condition of mixed sand and small
gravel, cliielly tlic latter, with a small i)crcentage of (kist.

Tlie pulverizer is constructed solely for the; pulverization or re-
duction to dust of sand, gravel, or the small work of stamping
machines, and cannot he used itself as a crusher or breaker. It
consists of four parts or elements, all of wliich are necessary to
its use. Tlic lirst is an automatic feeding-mill, wliich furnishes a
regular and constant supply of the material to be pulverized.

The second element is an iron drum or cylinder, containing an
air-wheel, which converts the sand or gravi-l into dust by the
action of rotary ciu'rents of air, created by the wheel. No air
enters or escapes from this cylinder, unless by the aid of other
machinery. The material can be retained in the cylinder imtil
it is completely reduced.

The third element is a fan-blower, — placed near, or at a con-
siderable distance Irom, the liulverizing cylintler, — by which the
dust is drawn from the lattm* as fast as it is generatcid. The
gravel, sand, auriiVrous earth, or other material, is pulverized in
the first cj-linder by the action of currents of air generated I)y
the air-wheel ; the dust is then drawn out, in company with air,
by the exhaustive force of the fan-blower. The fourth element is
a chamber, or series of chambers, to receive and collect tlu; dust
generated by the pulverizer. The dust-chambers are variously
constructed to suit the nature of the material which is to be re-
duced, and are adapted either for dr}^ or wet grinding, as may ]je
I'cquired. A single liulverizer, applied to the reduction of gold
ores, accomplishes with a smaller consumiMion of steam or water
power, the work of forty stamps, and the quality of the work pro-
duced is beyond all comparison finer. In a pulverizer theoreti-
cally perfect, the principle of its working is the movement of one
particle on another, or mutual attrition, promoted by vortices of
air.

Three pulverizers vnll give the work, in quantity, of ninety
stamps ; and the quality of this work will be so much superior
that the miner may safely estimate his profits at twenty dollars
per ton, instead of ten dollai-s, from quartz assaying thirty dollars.

In ordinary practice, but one element of an ore — that of most
prominent value — is sought for ; the other elements being re-
jected in slags or escaping in fumes from the furnaces. Refei*-
ence may be had to the loss of iron and sulphur from coj^per ores ;
the loss of copper, iron, and sulphur in worldng nickel ores and

MECHANICS AND USEFUL ARTS. 49

most of the gold ores of Colorado, California, etc. ; and the loss
of silver in working many of the copper and lead ores. Besides
these are many ores that cannot be worked by any of the present
methods ; or, at least, only where labor and fuel cost but little.
Of these are the low-grade copper ores, with which our country
abounds ; the mixed ores of galena and blende ; of nickel, copper,
and cobalt ; and of galena and silver.

To work an ore properly, every useful element should, if pos-
sible, be converted into a saleable commodity ; and the expense
of working the ore should be paid by the sale of those parts that
are now rejected as refuse.

The first step in our system is to reduce the ore to an impal-
pable powder.

For this purpose we have designed the breaker or whirling-
table, for splintering the ores by jiercussion, and the pulverizer
for reducing them to dust.

It will not be questioned that an ore in the state of powder is
in the best condition to be acted upon by chemical reagents.
Having, then, accomplished this first step, the next is the use of
the water furnace, which consists of a hollow tower or upright
flue of masonry, in the form of a truncated cone, and a horizontal
flue starting from its base. The bottom of the tower and flue is
formed by a water-trough, in which is a horizontal shaft, furnished
with paddles, which is made to revolve to keep the burned ore in
motion, that it may be thoroughly lixiviated. Around the head
of the tower are four fire-boxes, together forming a cross with a
voided circular centre.

Their tops are arched so as to form a flue inclining downward,
to approach the tower-head. Resting upon the tops of these
arches is a dome, which has a central opening, through which the
ores and reagents are fed into the furnace. At the extreme end
of the horizontal flue is a draft and spray-wheel revolving in a
chamber. A wooden flue or conductor leads from this to a second
wheel of the same character. We fill the trough with water,
kindle the fires, and set the draft and spray-wheels in motion.
The action of the wheels draws the converging flames from the
fire-boxes down the tower. These flames extend down but a
short distance, depending upon the kind of fuel used, and but
slowl}' heat the tower ; resort is therefore had to the use of pul-
verized fuel, in order to obtain the desired heat. There are two
fan-blowers ; one to supply air, the other to force powders of any
kind into the head of the furnace.

These blowers are now put in motion, the second one forcing
pulverized tan bark, or coal of any kind, into the flames jjro-
eeeding from the fire-boxes.

The minute particles of pulverized fuel, each surrounded by
its atmosphere of oxygen, ignite with intense combustion. Both
equivalents of heat are ajiplied at the point of work. By this
method, in the furnace we have now in operation, fifty pounds of
charcoal will create an intensely hot flame twenty feet long and
three feet in diameter, and lasting an hour.

The walls of the tower now radiate an intense heat inwardly,
6

50 ANNUAL OF SCIENTIFIC DISCOVERY.

which is, of course, greatest at the ]ioint of the intersection of the
ra3S, which is the centre of the tower'

If the oi*e to be worked be a sulpiiide of copper or iron, for ex-
ample, coutaininj^ sulphur suHieient for its own comi)lete combus-
tion, the supply of pulverized fuel is now cut oil', and the ])ulver-
ized ore fed into the furnace by tlie second fan-blower. Falling
into the focus of radiation, with a sullicient supply of oxygen from
the fan-blower, the oxidation of each element of the ore is almost
instantaneous.

Most of the ore falls at a bright red or white heat into the water
of the tank.

Many ores furnish their own fuel in the sulphur they contain.

When ores containing but little sulphur are to be burned, the
supj)ly of i)ulverized fuel nuist be constant.

in working ores containing copper, this metal is founil in solu-
tion with some iron, as a soluble salt, the nature of which will be
according to the character of the l)ath.

We have introduced important economies over the ordinary
methods of separating the two metals, and obtaining the precip-
itates. The separation and refining of the metal is eilected in the
solution.

In working the mixed ore of sulphides of lead and zinc, the
lead is found as a sulphate in the bottom of the water-tank, and
the zinc as sulphate in scdution.

Not the least interesting ieatures in oxir system ai'e the applica-
tion of the pulverized fuel and its economies. There is not only
a large economy of heating force, but other consequences which
are found to be valuable.

It is a fair estimate, that, in working copper ores, this method
requires not more than one-eighth as much fuel as is required by
the so-called English or (ierman methods.

The eftect of the spray-wheel, which should perhaps be called a
water-pulverizer, in wetting down or couilensing dust and fumes
that would otherwise escape, should not be overlooked. The
general use of it will convert many losses into profits, — the
losses made in the ordinary methods of working copper, zinc,
and antimony ores for instance, — and by it many serious nuisances
will be abated.

HORSE-POWER.

Horse-power is a unit of force introduced by Watt, to enable
him to deteiTuine what size of engine to send to his customers, to
supersede the number of hoi'ses which the new power (steam)
was to replace. He ascertained, at a London brewery, that the
average force exerted by the strongest horse was sufficient to
raise 33,000 j^ounds one foot high in a minute ; thus, an engine
of 200 hoi'se-power would be a force equal to that of 200 horses,
each lifting 33,000 pounds one foot high per minute. Watt had
two methods of estimating and comjjariug his engines, viz., by
the poAver, and by the duty. By the jjower is meant the quantity
of work which an engine can etieet in a given time ; by the duty
is meant the quantity of work which it can etfect by a given ex-
penditm-e of fuel. Now, it is evident that, without any change in

% MECHANICS AND USEFUL ARTS. 51

the size of an engine, but simply by increasing the pressure of the
steam, the power of an engine may be greatly increased ; that is,
the load remaining constant, the speed of the piston may be in-
creased, the number of strokes may be increased, and consequent-
ly the work done per minute will be increased also. Hence it is
difficult to apply a limit to the power obtainable from the smallest
cylinder, provided the boiler be large enough to evaporate the
increased quantity of water, and strong enough to resist the
increased bursting pressure. In fact, no size of cylinder can be
reckoned as having a particular power, since the power depends
not on size but on strength. Nevertheless, in modern engineering,
the term horse-power refers rather to the size of the cylinder than
to the power exerted ; and the value of this unit has undergone
many changes, so that in a modern engine a horse-power may
imply 52, or 60, or 66,000 i^ounds, one foot high, per minute.

The plan now adopted for ascertaining the performances of dif-
ferent engines, is by an instrument called an indicator. This con-
sists of a small cylinder, fitted with a piston, which is pressed
down by a spring. By the height to which this piston rises
against the spring the steam pressure within the cylinder is indi-
cated ; and the number of pounds pressure on the square inch,
niultij^lied into the number of square inches in the area of the
cylinder, and by the number of feet travelled through by the
piston per minute, gives the impelling power; deduct, in large
engines, about one-tenth for friction, and the remainder is the effi-
cient moving power, which, divided by 33,000, gives the actual
horse-power.

ADVANTAGES OF SUPEEHEATED STEAM.

Mr. H. W. Bulkley of New York makes the following com-
munication in the " Journal of the Franklin Institute" for Octo-
ber, 1866. " Supei-heated " steam, or steam which has received
an increase of temperature without increase of weight, by the
direct application of heat, has enemies who stoutly maintain that
no benefit can be derived from the superheating, as the steam has
its maximum efiiciency as soon as generated.

The fallacy of such statements is evident on reflection, and
plainly shows that those advancing and upholding them have
neither practical acquaintance with the subject, nor have given it
serious thought. It is clear that, as the greater part of the steam
generated in boilers is obliged to jiass through the water above it,
on its way to the steam-pipe, it must unavoidably carry with it
much water in the form of spray, mechanically combined, and held
in suspension. When boilers " foam,'^ this operation is greatly
increased by unnatural causes, the delivery of spray becoming so
great as to seriously inconvenience the engine, and endanger its
safety, as well as that of the boiler. And, in boilers properly con-
structed and carefully operated, which may be supposed to work
dry steam, much more water than is generally conceived is con-
stantly carried over with the steam ; and this delect cannot be en-
tirely remedied, even by the most judicious arrangement of " dry
pipes," steam-drums, etc. What,' then, becomes of this water

62 ANNUAL OF SCIENTIFIC DISCOVERY. jp

mixed with the stoam, and which has been heated at the expense
of the fuel? It is tivident that it is useless lor power, and, as it
has no latent heat, it is very unavailable for heating or drying
purposes. It cannot act otherwise than as a " clog," causing
more friction in the sleam l)y its presence, inconveniencing the
operation of the engine, and tending to condense the steam with
which it is associated. Now, by superheating this wet, saturated
steam, it is converted into an elastic vapor, by the complete and
instantaneous vajjorization of its surplus moisture, Avhile its tem-
perature is raised sullicient to preserve it from premature con-
densation in passing to the cylinder, or to the heating or drying
coils. The volume and elasticity of the steam is thus increased
to a wonderful extent by a very moderate degi'ee of superheat-
ing, and its subsequent operation in the cylinder is highly satis-
factory. But another advantage in the system should not be
overlooked, and that is the expansion of the steam as a gas, by
the heat imparted to it after its surplus moisture has been evap-
orated. Although the greatest gain must ensue from the addition
of the first few degrees (say fifty) of heat, when the expansion of
the steam from its previous saturated condition is very great, yet
thehighest authorities agree, that, after it is thorougldy dried, the
steam follows tlie laws of gases, and its volume may be doubled
by the adilition of 4b0 degrees of heat. It is a fact proved by
most accurate experiments, that the higher the degree of super-
heating, the greater is the economy ; and if steam could l)e used
at a tem2>erature of 1,U0U degrees, its elliciency woukl be very
largely increased. Inasmuch as it is not practicable or conven-
ient with engines, as at present constructed, to use steam at such
extreme temperatures, we are unai)le to reahze the greatest econ-
omy of superiieating ; but, if ordinary steam of 50 pounds pr(!ssure,
at a temperature of 3U1 degrees, be superheated t(j 400, the addi-
tion of this 99 degrees of heat will augment its volume (or pres-
sure) more than 20 per cent., and will not rend(;r it at all injuri-
ous to the lul)rication or jiacking. Where this superheating is
effected by the waste products of combustion, the increase re-
ferred to is all clear gain ; but when acquired, as is frequently
done for convenience, at the expense of the fuel, a simjjle calcu-
lation shows that even then the economy from the expansion as a
gas is from 10 to 15 per cent., independent from that realized in
the vaporization of its surplus moisture, and which is as much
more. Saturated steam cannot part with any of its heat without
becoming condensed ; and this loss, by premature condensation,
is often a very large percentage of the total amount of steam
used. In every unit of the steam thus condensed, there are lost
1,000 units of heat, whicTi have been sui)plied by the fuel, but
have not been utilized. Superheated steam, imder the same cir-
cumstances, might lose all of its surplus heat, but would still exist
as steam.

In England, where the practical advantages of superheated
steam are more thoroughly understood and generally acknowl-
edged, its employment is common, and is attended with the most
satisfactory and economical results. The steamers of the " Penin-

MECHANICS AND USEFUL ARTS. 53

sularand Oriental Steam Navigation Company" have used snpei'-
licated steam for many years, and its Diri^ctors certify that it lias
saved them many thousand tons of coal. In this country, the
steamers of the "Bay Line," running; between Baltimore and For-
tress Munroe, employed superheated steam with an economy of
30 per cent, in their fuel. The steam, which was superheated by
means of an arrangement of tubes in the uptake, was maintained
at a temperature of 400 degrees in the cylinder ; yet a subsequent
inspection of its interior surface, after using this steam for several
months, showed it to be as smooth and polished as a mirror. The
writer's experience in the jiractical application of superheated
steam with stationary boilers has shown that where the steam
was superheated by the fuel about 100 degrees above the tem-
perature due to its pressure (giving a temperature of 400
degrees in the cylinder(, the saving in feed-water, or steam, was
nearly one-third, and the economy in fuel was one-quarter,
showing that from five to eight i)er cent, of the fuel was required
for supi^rheating the steam generated by the remainder, thereby
increasing its efficiency nearly one-third. With this temperature
maintained in the cylinder, by a judicious ari'angement of the
superheating apparatus, the operation of the engine was highly
satisfactory, no water being present to necessitate the opening of
water-cocks, or bring undue strains upon the cylinder-heads or
connections. It is hardly necessary to add that no appreciable
action could be observed upon the lubricants, packing, or working
surfaces of the engine.

The full economy due to the use of steam expansively cannot
be realized when it is employed in the saturated condition, owing
to its partial condensation during expansion. As heat and jjower
are correlative terms, steam cannot perform work without the
diminution of a portion of its heat, besides that lost by radiation.
This heat, coiTcsponding to the work done, may be taken from
superhe;ited steam without destroying its efficiency ; for it will
still remain in the cylinder, pui-e and dry, to the end of the stroke.
It can be confidently asserted, that no steam engine is entitled to
that name, if it employs a mixture of water and vapor instead of
the genuine article. The objections sometimes advanced on the
score of " want of durability" in superheating apparatuses may
be entirely removed by the exercise of a proper care in their
construction and application, and by the allowance of a liberal
amount of heating surface ; so that it is not necessary to subject
the superheaters to an undue degree of heat, which would natu-
rally tend to their destruction. These particulars faithfully com-
plied with, it will be found that no tangible objections can be
ojiposed to the employment of moderately superheated steam ;
and, when such economical results obtain from its use, it seems
imaccountable that it is not more generally appreciated, and that
the manufactui'ing public still adhere to the old saturated article,
wasting by it botli their time and money. The jiractical advan-
tages attending the use of superheated steam, either when used
as power, or for heating and drying purposes, are immense ; and
it is to be hoped that, with the increased diifusion of knowledge,
6*

54 ANNUAL OF SCIENTIFIC DISCOVERY.

tlie old projuflices afrainst it may be removed, while its true
merits are openly and universally acknowledged.

HOLLOW STAY-BARS FOR STEAM-BOILERS.

The safety often of many pei-sons depends on the efficiency of
the stay-bars of a steam-boiler; but too often their importance is
not suliieiently recognized, or tiiey are weaker or less numerous
than they should be, that a little additional i)rofit may be made by
tht^ l)oih'r-maker. A btiil greater source of danger exists when
tiiey have been used, Ijut have become so corroded as to be prac-
tically worthless; which, from thoir position, is very likely to be
tiie case, and without its being j)robal)le, or jjcrhaps possible, to
discover the change they have undergone, A very simple and
elYeetive way of making them ])roelaiin tlieir own inefficiency is
now in use on the Nortliern Railway of France. They are made
with a small l^ore from end to (md, and thus when one of them
gives way, or is seriously corroded, the steam or water escapes
through in such a way as infallibly to attract attention. To pre-
vent their being stopped up by dust, etc., their extremities, where
not otherwise protected, are loosely closed with wood, etc., which
is easily liiown out by the escaping steam or water. From the
smallness and position of the bore, which is exactly in the centre,
the rod is scarcely at all weakened by it, but the necessary strength
may be secured by a very slight augmentation of its diameter. —
Intellectual Observer, April, 1866.

MONT CENIS RAILROAD.— CENTRE-RAIL SYSTEM.

On account of the long time which must yet be consumed be-
fore the Mont Cenis Tunnel is finished, — four and a iialf mih^syet
remainnig to be execut(id, — it is proposed to place a temporary
track over the summit of the mountain. An experimental line of
one and a fourth miles has been constructed on the most difficult
))ortion of the route. By the report of Capt. Tyhir, of the Royal
Engineers, this distance is ascended in eight and a half minutes
with a load of sixteen tons, though the average grade is as steep
as one in thirteen, and at a maximum of one in twelve. The
plan adopted toobtain adhesion is an arrangement of horizontal
drivers biting on a central rail. This plan, though regarded as
new in Europe, was long ago patented and used in America. —
Journal of the Franklin Institute, Nov., 1865.

A paper on the same sulyect was communicated to the British
Association, in 18GG, by Mr. J. B. Fell. After alluding to the
various difficulties presented to the advance of railways by moun-
tain ranges, and the efforts made to overcome them, it was stated
that the use of the centre-rail Avas first thought of by Messrs.
Vignolles and Ericsson, in 1830, and proijosed to be applied to the
inclines on the Manchester and Liverpool Railway ; but it was not
put into opei-ation. In ignorance of what was then done. Baron
Leguir, in France, the writer, and others, also applied their minds
to a solution of the problem of constructing railways over steep
gradients. It was not till Mr. Brassey and the writer built a
centre-rail engine, and laid down a length of line on that plan on

MECHANICS AND USEFUL ARTS. 55

the Cromfovd and High Peak Railway for experimental purposes,
in 1863, that tlie system Avas put into practical operation, the
experiments being entered into in order to satisiy the Italian Gov-
ernment as to the feasibility of laying down a line on a similar
principle over one of the Alpine passes. The mean gradient of
the first twenty-four miles of line, from St. Michael to Lausleburg,
is one in sixt3', Avith a maximum gi-adient of one in twelve ; the
other twenty-four miles, the mean is one in seventeen ; and over
the whole length there are at intervals curves of two chains radius.
The line rises to an elevation of seven thousand feet, and is ex-
posed in places to avalanches and heavy snow-drifts ; but it will be
suitably protected. The system of locomotion adopted was that
of a third or traction rail, on which adhesion could be obtained by
horizontal wheels, worked by the engine in conjunction with or
independently of the ordinary driving-wheels, which admitted of
the weight of the engine being reduced to a minimum, while the
pressure upon the middle rail could be carried to any required
amount, and gradients of one in twelve worked with as much
certainty and safety as those of one in a hundred. The centre-
rail also furnishes the means of applying most powerful brakes
for controlling the descent of the trains, and greatly diminishes the
frictional resistance in passing round sharp curves. Besides this,
the centre-rail rendered it almost impossible for the train to leave
the rails. The first experiments were tried in the Cromford and
High Peak Railway from September, 1863, to February, 1864.
The weight of the engine and load was from sixteen to seventeen
tons. It never failed to take loads of from sixteen to twenty-four
tons up gradients of one in twelve, or in working round curves
of two and a half chains radius on that incline, the brakes having
perfect control over the train on the ascent. Certain improve-
ments suggested themselves, — the boiler-power was insufficient,
the inner machinery too crowded and inaccessible, and the con-
necting-rods, working at too great an angle, by an irregular,
impulsive movement, diminished the adhesion of the horizontal
wheels. The improvements were made and further experiments
conducted with special reference to the requirements of the Italian
Government, which included three trains a day each way, the mail
train to perform the joui'ney at an average rate of twelve miles
ah hour, including stoppages, the speed up the steepest incline
being seven and a half miles an hour, while the gross weight of
the train was to be sixteen tons. The mixed and goods trains
were to carry forty and forty-eight tons each, with two engines.
The traffic on these trains represented a return of £100,000 an-
nually. The writer described the official trials in Italy in the
presence of the representatives of the English, Italian, Russian,
and Austrian Governments. The I'esult of the trials exceeded the
estimate both as to speed and weight of the trains, and Captain
Tyler, who represented the Board of Trade, reported "that this
scheme for crossing the Mont Cenis is, in my opinion, practica-
ble, both mechanically and commercially, and that the passage of
the mountain may thus be elfected, not only with greater speed,
certaint}% and convenience, but also with greater safety, under

56 ANNUAL OF SCIENTIFIC DISCOVERT.

the; present avrano-omcnts. . . . There is no diiricniltf in so ap-
plyiiii;" and securing; tliat middle-rail, and niakiii<^ it virtually one
continuous bar, as to iM'eclude the possibility of accident from its
Aveakness or from the failure of its fastenings; and the only ques-
tion to my mind is whether it would not be desirable still further
to extend its application to gradients less steep than one in twenty-
four, with a view to greater security, especially on curved portions
of the line." Similar favorable reports were quoted from the
French Imperial Commissioner, while it was stated that those of
the Italian, Russian, and Austrian Commissioners were e<iually
favorable and conclusive. In November and December last, the
Frenc-li and Italian Governments granted concessions, authorizing
the railway on the Imperial postal road ov(;r the JNIont Cenis with
a width of about thirteen English feet; and a company has since
been formed to carry out the undertaking. The works were com-
menced in March, and the line is cxiiected to open in May next.

Attention was directed at some length to the conditions essen-
tial to the success of the system, the lirst of Avhich was the em-
ployment of different ty^ies of engines, according to the heaviness
of the gradients ; of each of which full descriptions were given,
with the aid of colored diagrams. The carriages, as well as the
engines, are each furnished with four horizontal wheels, wliich
have flanges underlapjiing the centre-rail. These act both as
guide and safety wheels, i)reveutiug the carriages from leaving
the rails, and, hx guiding them round the curves, greatly dimin-
ish the irictional resistance and the tractive power required,
thereby rendering it easy to reduce the weight of the engine to
that which was necessary for producing and carrying the power
required for the traction of the train. The economy of weight
has been effected by a simpler arrangementof the machinery, and
by using an improved quality of material. For the making of
mountain lines, which ai"e exposed at certain seasons to an unfa-
A'oraljle climate, from the effects of snow, frost, and fogs, it was
desirable to devise some means of cleaning the surface of the rails,
and for improving the state of adhesion as the trains advanced, so
as to dispense with the use of sand. This might be done at speeds
from five to ten miles an hour ; ice and snow might be cleared off
by cutters attached to the engine; and, in seasons of mist, ne.w
machinery could be probaljly contrived for removing that almost
imperceptible film of mist which diminishes the adhesion to nearly
the same extent as ice. The adhesion was best in the winter,
when the snow remained for months in a state of dry powder ; but
the places where it accumulated were protected by covered ways,
and the rails were always in good condition.

He said that the centre-railway system was never intended to
be worked on any except the steepest inclines, where no other
engines could work. It would be only necessary to have a cov-
ered way for fourteen kilometres, which would cost £40,000. One
kilometre in the avalanche district, which was well known, would
have to be pi'otected by stone ; but the remainder would he pro-
tected by wood, which was amply strong enough to resist the weight
of from twenty to thirty feet of accumulated snow. — Reader, 1866.

MECHANICS AND USEFUL ARTS. 57

PNEUMATIC RAILWAY.

The Pneumatic Dispatch Company have successfully applied
the jjrinciplo of atmospheric pressure to the conveyance of letters
and merchandise, and thus aiforded an opportunity of showing
that human beings may continue without inconvenience in a closed
tube. This removal of an ajjparently insuperable objection to
atmospheric propulsion is very important, since, witli a pneu-
matic railway, the danger of accident is reduced almost to nothing.
Collisions are imjiossible ; and, as the train cannot get off the line,
the greatest velocity is unattended with danger. The view of
external objects is excluded ; but tins privation is little greater
than that experienced on ordinary railways, where there are many
cuttings, tunnels, and interposed objects. With an atmospheric
railway, the exjjcnse of construction and maintenance are greatly
diminished ; steep gradients and sharp curves cease to be objec-
tionable, since an ascent of one in fifteen, or a curve of eight
chains radius, causes no inconvenience, and great facilities are
afforded by it for passing under rivers.

The tubes of the Pneumatic DisiDatch Company have been in
operation for more than three years, in conveying parcels ; and the
applicability of the system to carrying passengers has been amply
demonstrated. The line of the Waterloo and Whitehall Railway
is to cross the river just above Hungerford Bridge. The tube is
made in four sections of two hundred and thirty feet length each.
The ends of these will be connected by being introduced into
junction cliambers foiiued in the bi'ick piers on whicli they rest,
the joint being made water-tight. These piers do not rise as high
as the present river bottom, and a channel will be dredged across
the river to receive the tubes, though the principal weight will be
supported on tlie piers. One of tlie tubes is now completed at
the ship-building yard of Messrs. Samuda, at Pojolar, five miles
below its intended situation. It is twelve feet nine inclies in diam-
eter inside, and is of tliree-quarter-inch boiler-plate, surrounded
by four rings of brick-work, which is firmly held by cement and
flanged rings riveted to the plates. Its weight, as it lies, is nearly
one thousand tons. To convey it to its destination, the ends are
to be closed by bulkheads, and then, having a buoyancy when
in the water of about tin-ee hundred tons, it will be floated up the
river and brought into position over its piers. An inner ring of
brick-work will then be built inside it, and just enough water
admitted to sink it upon its foundation. The joints between tlie
tubes and piers will then be made water-tight, and the bulkheads
removed from the ends of the tubes. The four tubes will thus form a
great sub-aqueous bi-idge of four spans of two hundred and twenty-
one feet each, the tubes resting in a channel dredg-cd across the
bottom ot the I'lver, but being chiefly supported upon massive
piers which do not rise even to the river bottom. The coflter-dam
at the Whitehall end of the line is no less than fifty-three feet
deep.

When the underground tunnel was finished from Holborn to
Easton Station, a distance of two miles, a train of goods with an
attendant was sent through the whole distance in five minutes.

68 ANNUAL OF SCIENTIFIC DISCOVEKT.

It appears from recent experiments conducted by the London
Pneumatic Conipnny, tluit ont; liundred and twenty tons of o;oods
can be sent through their eighteen miles of tubes every hour, at
a cost less than one penny a ton per mile. — Intellectual Observer
and Scientific American.

AERIAL LOCOMOTION.

A pamphlet has lately been published on this subject by Mr.
Bonllon, from which may be gatiu'rccl many interesting facts.
After giving it as his opinion that balloons will never jn'miit us,
safely and at pleasure, to navigate the air, on account of the A^ast
surface tliey present to the action of the wind, he proceeds to
show that if the prol)lem of aerial navigation is to be solved, the
encumbrance of balloons must be altogetiier dispensed with, and
an engine must be devised capable of lifting its own weight and
that of an aeronaut into the air, and of continuing to exert the
power requisite for this purpose for a consideral)l(! time. Tlierc
is no dillk-ulty in devising mechanical instruments lor aerial ])ro-
pulsion antl guidance. Earlier projectors j^i'iricipally aimed at
imitating (lie wings of bii'ds; but since the use of the screw for
the pr()j)ulsion of steamers, the employment of a similar propeller
for aerial locomotion naturally suggests itself. The action of such
a contrivance is illustrated by a small toy called the Stropheore,*
sold for the amusement of children ; Avhen a string pulled by the
hand, giving a rapid rotation to a miniature propeller, (muses it
to rise in the air. It is also illustrated by fire-works called the
Chinese turbine, which rise similarly in the air when caused
rapidh' to revolve by the combustion of the explosive mixture.
Tliere is no reason to apprehend any particular difllculty in the
mechanical adaptation of this principle to the purpose under con-
sideration. The real difficulty lies in obtaining a suitable motive
power, i. e., one capable of furnishing a sufficiency of power with-
out weight. In the case of the steam-engine, which first occurs
to the mind as the joossible agent of the propulsion, the chief ob-
jection is the Weight of the boiler, coals, and water ; that of the
cylinder, i)iston, and moving pai'ts being comparatively trifling.
The caloric-engine, although dispensing with the weight of water,
does not on the whole offer prospect of advantage. Another
source of motive power is offered by the combustion of gas, i. e.,
by exploding a mixture of inflammable gas with atmospheric air.
In a gas-engine constructed on this principle, the weight of the
boiler, coals7 and water necessary to the steam-engine is alto-
gether dispensed with ; the place of these being supplied by a
receptacle of gas, a source not of weight but lightness. There is
one difficulty, however, viz., that if the receptacle of gas be
large, without which long journeys would be impossible, diffi-
culty of propulsion and guidance, as in the case of a balloon,

* In the Stropheorg we have a few liglit ^\ings placed obliquely around a central
stem: h\ the action of the hands witli a string, as in a hummiiig-top, rotation is
imparted to those wings, and immediately the machine rises, and pierces its way
through tlie air. !>o long as t!ie motion continues, this ascent is continued, because
the ail-, subject to great compression, yields to impulsion before it has time to veer.

MECHANICS AND USEFUL ARTS. 59

would be created. This evil would be remedied, though not
without sacrifice of lightness, if a stock of petroleum were carried
instead of a receptacle of gas, and tlie vapor of petroleum used
instead of gas for explosion, with a due admixture of atmospheric
air. Another source of motive power is afforded by solid explo-
sive substances, i. e., by comjiounds which on combustion gener-
ate a large volume of gaseous products. Such are gunpovv'der,
gun-cotton, the mixture used for rockets, etc. In case of an en-
gine worked by such power, the weight of boiler, fuel, and water
necessary to the steam-engine is replaced by that of the suj^ply
of explosive material, whereby for short journeys a great reduc-
tion in weight is ett'ected. There are some further considerations
which seem to show that these powers are capable of achieving,
to some extent, the desired result, which the steam-engine, prob-
ably with justice, is pronounced incapable of eft'ecting. If a very
diminutive steam-engine could be made capable of raising itself
into the air, a powerful steam-engine could be made to do so
likewise ; for the ratio of weight to power is greater when the
steam-engine is small than when it is large ; and this holds good
in the case of most machines or engines. Now, rockets are actu-
ally made capable of lifting themselves into the air, and if small
rockets can do this, surely, in accordance with the above princi-
ple, large rockets can do so too, and in proportion to the size of
the rocket, its power of lifting a load will increase ; and if this be
so, it must be possible to construct a rocket, or a combination of
rockets, capable of lifting from the ground and transjiorting to
some distance the weight of a man. The weight actually lifted
by the larger Congreve rockets is not inconsiderable ; but it is
proper to consider that this would be greater were the power of
the gas brought differently into play. For the rising gas acts
much more advantageously when the rocket is movins: at a his'h
velocity than when it is stationary, — a large projiortion of its
power being Avasted in the latter case. Could the j)ower act as
advantageously when the rocket is stationary as when it is
moving at full speed, it would be caj^ablc of lifting from the
ground a greater weight than it actually does ; and a greater
suj^ply of material being lifted, an increased range of flight could
be obtained. For this reason, a rocket, however great its power,
would be wholly unsuited to the purpose of aerial navigation ; it
being impossible to retard its speed without diminishing the
power exerted by it. But no such objection exists if we conceive
the gas to produce motion, not directly, but by means of a pro-
peller. For the propeller may revolve at full velocity, and thus
the maximum of availaljle power be brought into play, Avhile the
engine itself is moving through the air slowly or not at all. The
same reasoning holds in reference to the Chinese turbines — i. e.,
that the ratio of weight to power would l)e greater Avhen they are
small than when they are large. And in this case, if a small tur-
bine can lift itself into the air, a fortiori, a large one can do so.
Such considerations seem to show that, though the steam-engine
may be wholly incapable of accomplishing the feat in question,
yet that other powers now known to us are capable of effecting

60 ANNUAL OF SCIENTIFIC DISCOVERY.

it to porno extent. Suppose, however, that this be so, the ques-
tion still remains: " WJiat ran^^e of llijzflit could be attained by
means of any power now known to us?'' This would of course
be limited by the quantity of material (whether petroleum, gun-
cotton, or anj^ other sul).stance) wliieli it would be i)ossibl(! to lift
into the air; and ex|)eriment alone would determine this point.
^It does not seem very bold to anticipate that a range of llight
equal to that of a cannon-ball might be found attainable without
much dillieulty; and if once such a i)eginning l)e made, improve-
ments might l)e exi>ected to follow, enabling greater distances to
be performed. Another question is that of cost; this would,
of ct)urse, mainly di-jiend on the nature of the material available
for the purposes. Could the desired ol)ject be achieved by the
use of petroleum, the cost would be comparatively moderate;
wiiile if it were necessary to employ gun-cotton, the inixlure used
for rockets, or similar explosive cimipounds, the cost would be
very great. It is obvious that in anj' case such a means of loco-
motion would be lar more costly than thos(! now jjractised on
hind and water, and wholly unlilted to compete with lliem for
ordinary i)urposes. At the same time, it is manifest that there
are numerous occasions, especially in warfare, where the power
of moving in any desired direction througli the air, even for veiy
moderate distances, would be of great service ; and cost for the
accomplishment of such an object would not be grudged.

ON THE USE OF STEEL FOR RAILWAY PURPOSES.

The application of steel to many of the purposes for whieli iron
bad been and is now generally us(;d, had been limited b}^ the
difficulty in producing steel in sufficiently large masses, at a com-
paratively low cost, and free from flaws, with a perfect homoge-
neousness of material, — this seemed to present an almost insu-
perable difficulty to its general employment. Cast-steel made hj
cementation, while possessing superior hardness, lacked tenacity ;
if tough, it was soft; if hard, it was brittle. In 1851, however,
Krupp, of Essen, Prussia, showed, in the London Exhibition, an
ingot of cast-steel wt.'ighing 4,500 lbs., the heaviest then known.
In 1862, he exhiijited another one weighing twenty tons, in the
form of a solid cylinder, nine feet high and three feet eight in-
ches in diameter. It had been broken across to show its fracture ;
under a good microscope it Avould not exhibit a single Haw.
Since then he has repeatedly produced masses of forty tons
weight.

There can be no reason, at this late day, and in view of the ex-
periments made in England and on the continent, for doubting
the superior durability, and the ultimate superior cheapness, of
steel rails and tires over those of iron. On our railroads it is
theoretically correct to say that the weight of a load rests on a
point ; but it is not practically correct. Thei-e is comjiression ;
much of it in the road, itself, or the rail, but some of it in the
wheel or tire. Yet, notwithstanding that it can be demonstrated

MECHANICS AND USEFUL ARTS. 61

thai this compression makes what would otlaerwise be a level
road oue continually uji-hill, there are persons who advocate a
yielding foundation, as there are those who insist on a springing
or yielding tire. The mere fact that our ordinary locomotive tires
must be occasionally re-turned is a suliicieut refutation of their
l^osition.

A perfectly rigid bed or road-way, and as rigid wheels, is the
rule that is found by ex2)erience to be the best. Soon as a wheel
or tire gets " out of round," it becomes, in oi^eration, a hammer,
destroying the rail. Mr. ]3essemer, at a recent meeting of the
British Association at Nottingham, gave an exceedingly elaborate
and interesting account of his own system of manufacturing
steel, and showed the vast importance that branch of industry
had assumed since his patent had come into working operation.
By the old system, forty pounds of steel was the largest mass of
metal oj^erated upon ; but by his process as much as twenty -five
tons could be converted into steel in one heating. It had super-
seded iron wherever large castings were required, such as ord-
nance of large size, locomotive and marine engine-Teranks, I'ails,
etc. He mentioned, as showing the superior durability of steel
rails over those of iron, that at the station at Camden Town, at a
part of the line over which all the traffic passed, a steel rail was
placed on one side of the line, and an iron rail on the other, and
that seventeen faces of the iron were worn away, Avhile the first
face of the steel rail was still in working order. Steel rails put
down four years ago were still in working order. The first cost
of steel rails was, of course, much greater than that of iron, but
compensation was found for this in the greater durability.

The superintendent of one of our most successful railroads in-
forms us that iron rails on that road average about seven or eight
years of life. Steel rails have been recently introduced, but the
test is not considered sufficient to afibrd proper data for an opin-
ion. Steel tires have been used on the I'oad several years, some
of them having already run 70,000 miles, and, while costing
double the j)rice of iron, their durability has proved that they are
superior to iron ones. No such performance, we are certain, can
be recorded for iron tires. The " best iron tires " — according to
Thomas Prosser, C. E., who has lately issued a pamphlet on'this
subject, which should be a satisfactory exhibit to our railroad men
— "average only 60,000 miles, during which time four of them
will grind up one ton of rails."

It appears to be evident that our railroad companies will event-
ually save by replacing their iron rails, iron tires, iron Avheels,
and iron locomotive axles, with those of steel, the rails to be laid
on an unyielding and permanent foundation. Certainly, this sub-
ject of the comparative value of iron and steel for these pur-
poses is worthy more general attention than has been given it in
this country, especially in the construction and "plant" of new
lines of railways.

The surprising results that have appeared where steel rails have
been laid alongside of iron rails, in places subject to very heavy
traffic, have already caused their adoption on nearly all lines for
6

C2 ANNUAL OF SCIENTIFIC DISCOVERT.

use near stations, and at all places Avhere the Avay is liable to
fi'i-eat deterioration. Tlie great Northern Railway has adnjited
them for use on all their inclines, wliile llie London and North-
western Company liave erected Avorks of their own capaldc of
supplying three hundred and lifty tons of steel per week, three
lumdriid of which is worked up into rails. The question is merely
one of first-cost and interest, and it is now pretty generally con-
ceded that steel rails at £l'> per ton, lasting forty years or longer,
are cheaper than iron at £7 10s., lasting eight years, especially
when it is considered that, on account of its superior strength and
stillness, a steel rail weighing seventy pounds to the yard is more
than e(iual to an iron rail weighing eighty pounds.

At lirst it was urged that steel rails, when worn out, Avould be
useless from the impossibility of piling and re-rolling them, while
old iron rails could easily be re-worked in any desired manner.
All fears on this ground have, however, proved (juite unnecessary,
as numljcrless uses have been found for which the old steel i-ails,
as well as the crop ends formed in their manufacture, are desired,
so that these bring readily from £7 to £.S per ton. Among these
uses may be mentioned rolling int(j plates, to be used in making
k(>ttles, by stamping, instead of charcoal plat(! ; plates for nail-
cutting, telegraph wire manufacture, and hundreds of other pur-
})0ses for wiiich the metal is extnmicly vahialde. Or it may be
re-melted in the converter or otherwise, and be again produced as
rails. As stated in mj'' last letter, the 2:)roduction of steel rails in
England already amounts to one thousand tons per week.

Tiu! Ibrm of rail in vogue on the Continent is the single headed,
but, like the English, live inches deep. Here, also, steel is taking
the place of iron on many lines, Mith a corresponding decrease in
the expenses for renewals.

The " London Railway News " says : " Mr. Williams furnishes
some details whieii will serve to show the enormous wear and tear
to which the rails of our leading lines are subjected. On the section
between Hatfield and London, on the Great Northern line, 57,536
trains, carrying 17,700,926 tons, destroyed in three years the rails
laid down in 1857. Some heavier I'ails, laid in 1860, Avere worn
down in three years by 65,529 trains, and 13,484,061 tons. In the
case, hoAvever, of a section of raihvay betAveen Bury "and Accring-
ton, 62,399 trains, and a gross tonnage of 12,451,784, passed over
rails Avhieh lasted scA'en and a half years, or tAVO and a half times
as long as those of the Great Northern, Avith about an equal amount
of traffic. Again, at Bolton, it required 203,122 trains, and 38,-
803,128 tons, to Avear out the same description of rails in seven and
a quarter years. The cause of this rapid wearing out of the rails
of the Great Northern as compared with those of the other lines,
is due, apparently, to the greater speed of the trains. In the case
of iron rails, as in the delicately-constructed mechanism of animal
life, it is ' the pace that kills.'

" Tavo steel rails of twenty-one feet in length were laid on the
2d of May, 1862, at the Clialk Farm Bridge, side by side Avith two
ordinary rails. After having out-lasted sixteen faces of the ordi-
nary rails, the steel ones were taken up and examined, and it Avas

MECHANICS AND USEFUL ARTS. 63

found that at the expiration of three years and three months, the
surface was evenly worn to the extent of only a little more than a
quarter of an inch, and to all appearance they were capable of
enduring a great deal more work. These two i-ails had, during
the period of a little more than three years, been exjjosed to the
traffic of 9,550,000 engines, trucks, and carriages, and 95,577,240
tons. It is an amount of traffic equal to nearly ten times that
which destroyed the Great Northern rails above referred to in
three years. The result of this trial was to induce the London
and Northwestern to enter very extensively into the employment
of steel rails ; and we learn from Mr. Webb that in a short time
arrangements will be made at Crewe for the production of three
hundred and fifty tons of steel per week, of which three hundred '
will be used for rails ; and that at the present time there are about
fifty miles of steel rails in use on the line, and three thousand tons
of steel-headed rails."

An examination of the steel rails laid down two years and a half
since in the Woodhead Tunnel of the Manchester, Sheffield, and
Lincolnshire Railway, resulted in a striking illustration of the I'el-
ative endurance of steel and iron rails. This tunnel is about three
miles long, v/ith a station at each end, where trains generally stop,
and where the wear of the rails is extraordinary, from the starting
of heavy trains with the aid of sand on iron constantly wet with
drippings from the roof. The life of an iron rail at these stations
was but about five months on one head, and three or four months
. on the other, after turning. The new rails are seventy-five pounds
Bessemer steel, double-headed, two and a half inch face, five-
oighths inch stem, and five inches deep. Rails were taken out at
the places of greatest wear, at each end of the tunnel, and on
being carefully measured and compared with the original tem-
plates from which they were made, were found to have lost as
nearly as possible one-eighth of an inch in the thirty months' use,
under at least 8,000,000 tons of traffic, as computed from the books
of the station. The rails were in admirable condition, and good
for five times as much further wear, both heads together ; making,
in insurance phrase, an " expectation of life " equal to fifteen
3'cars, or twenty times as long as that of iron. — Svientijic Ameri-
can, 1866.

CHILLED RAILWAY WHEELS.

The practice with Major Palliser's shot against armor has shown
what are the qualities of chilled cast-iron ; the chill, in this case,
extending quite through the casting. It has been demonstrated
that it is equal in hardness to hardened steel, and that it requires
even greater force to break or deform it. It may be that the
startling results obtained at Shoeburyness will serve, in some
measure, to account for the universal use of chilled railway wheels
in America, and for the leading wheels of engines, and often for
the driving-wheels themselves as well. It has always been the
belief in this countr}^ that those wheels were used liecause they
were cheap, and because the Americans could aft'ord nothing bet-
ter. These wheels, before the war, cost about one and a half

64 AXNUAL OP SCIENTIFIC DISCOVERT.

ponce per pound, or rather less than £14 per ton ; and one favorite
pattern of two feet six inch wheel, weighing: nearly four hundred
weight, was sold, ready for boring, for £2 lOs. each. But so far
from their eheapness having ali»ne maintained them in use, they
Were long ago adoi)ted on the Grand Trunk Railway of Canada,
because they wore found, upon tlie whole, l)etter than Avrought
iron. We have l^efore us a letter, written, in 18r)9, by the late ^Ir.
A. M. Itoss, engineer to the Victoria Bridge, ]\Iontreal, upon this
subject, and which contains this statement, a statement wliieh we
know to have been conlirmcd by the subsequent experience of the
engineers of the Grand Trunk Railway. In the International
Exhil)ition of 18(52 were; a ])air of chilled wheels, two feet nine
inches in diameter, which liad run upward of ir)(),(H)0 mihis under
a heav}' post-oliiee van on the Ciran<l Trunk Railway, and, although
worn, they were still in good condition. We need not dwell upon
the severity of a Canadian winter, nor explain how for months
togother tiic road bed — and there is seldom much ballast — is
frozen as hard as rock.

This, if anything, would be expected to try chilled wheels ; yet
they are regularly cmi)lovcd for tiie leading-wheels of i)ass(niger
engines; and breakages, altliougii not al)S()lutely unknown, are at
least as infrequent as those of the best makes of English railway
carriage-tires.

It requires good iron for chilled wheels. That used in America
for this l)ranch of manufacture is mostly cold-blast charcoal iron;
and it has to be selected and mixed with care to oljtain the proper
qualities of sti'ongth and hardness of chill. The chill should be
from three-eighths to five-eighths of an inch deep, and should cover
tilt! wiiole tread and the wearing face of the flange. Chilled
wheels require especial provision for cooling after being cast, so
as to avoid internal strain from contraction. The wheels do not
all come out of exactly the same diameter ; but there is no diffi-
culty in mating them in ])airs of equal diameter, the greatest van-
ation in the iliameters of a thousand two-feet-nine-ineh wheels
hardly exceeding one-eighth of an inch. The machinery employed
for boring is such that the hole is necessarily in the centre, so that
no eccentricity is possible. The wheels wear evenly and very
slowly, until their diameter has been reduced by nearly half an
inch. American iron, of choice quality for chilled wheels, is now
being taken to St. Petersburg for casting there the wheels of all
the carriage and wagon stock of the St. Petersburo: and Moscoav
Railway. Heretofore the wheels for that line have been imported
largely from the States. Our own size of wheel has never been
adopted there ; and as the weight of disk-wheels increases in a
higher ratio than that of the increase of diameter simply, we pre-
sume that a three-feet-six-inch wheel, instead of weighing but
five hundred weight, as in English practice, would reach six hun-
dred weight. We learn that iron of the proper quality for chilled
wheels is likely to be introduced into this country, and that they
will ijrobably receive a fair trial.

We believe that five American chilled railway wheels have
arrived in London, and. that they will be broken experimentally,

MECHANICS AND USEFUL ARTS. 65

and tliat further wheels of this kind will be sent over for trial
under English rolling stock. We have samples of the iron from
Avliich these wheels are cast, and it is of magnificent quality.
The fracture is a rich dai'k gray, medium-grained, and shows
great toughness, the particles aj^pearing to have been irregularly
torn, rather than broken short off. The specific gravity ranges
from 7.25 to 7.3185, and the tensile streno'th from 32,000 to 35,-
102 lbs., or, say, fourteen and one-half to sixteen tons per square
inch. The iron is that known as the Salisbury cold-blast charcoal
iron, and is worth about £10 per ton in New York. — Engineer-
ing, 1866.

STEEL LOCOMOTIVE WHEELS.

Railway companies in England have for some time largely
employed steel as a substitute for ordinary iron, for the working
parts of locomotives, with most satistactory results. On heavy
freight-lines it has been found that with the ordinary iron tires, or
the engine-wheels, the distance run was not more thaii 90,000
miles, — in many cases noj, more than 60,000 miles, — and the
wheels require to be taken from under the engine for every 20,-
000 or 30,000 miles run, for repairs and "turning up." In the
case of steel tires, however, the Avheels will run 100,000 miles,
before they require " turning up " or repairing. The "Hallway
News " states that the result of a very careful examination of the
efiects of wear, lead to the opinion that these wheels will run
from 350,000 to 500,000 miles, or equal to some twelve or fifteen
years' work of a daily average of about one hundred miles. The
difi'erence of cost between the two metals is not great ; in the one
case it ranges from £40 to £-15 per ton, while the steel is about
£55 ; the cost of labor in placing the tires being about the same in
each case. It is confidently stated that a similar saving in point
of wear may be made by substituting steel for iron in boilers,
axles, cranks,, eccentrics, and other j)ortions of locomotives. —
Mechanics'' Magazine, April, 1865.

HIGH TEMPERATURES TRODUCED BY GAS.

There is no reason why the very highest temperatures should
not be produced by the combustion of gas ; and in reality it has
been found that by regulating the supply of air and gas, and pre-
venting the caloric evolved from being dissipated, a very great
heat may be obtained. For this purpose, it is only necessary to
combine a number of flames produced by Bunsen bui'ners, but
without permitting them to comj)letely penetrate one another,
and causing a draught by means of a sheet-iron tube about two
metres high. The heat, by a projoer management of the flame,
and by the products of combustion being made to act on Ijoth
sides of the refractory envelope within which the substance to be
operated on is placed, becomes extremely powerful. With such
an arrangement it was found that two square metres of gas, burned
under a pressure of five or six centimetres of water, fused six
hundred and seventy grammes of silver in fifteen minutes ; and
6*

66 ANNUAL OP SCIENTIFIC DISCOVERT.

five luintlrod 2:i";i»ini('s of very inf'nsilile cast-iron in thirty min-
utes. — Intdledual Observer, March, 180G.

PETROLEUM AS A FUEL.

Mr. C. J. Ricliarilson has so Hir succeeded in ntilizinj? petrole-
um as a steam fuel for marine enjjines, that at a recent trial of
his iini)roved petroleum boiler, at Woolwich Dockyard, the most
favoral)le results are said to Iiave accrued. It is re])orted that
tlie boiler vaporized aljout three thousand pounds of water, at the
rate of thirteen and a half ixnmds to one pound of fuel, in about
three hours, the lowest class of English coal beino; used. Petro-
leum is tlie ijxact ojjposite of coal ; it is slow burnin<r, permitting
little waste, requiring a small fire-box and no ash-pit. An ash,
the petroleum coke, forms itself on the surface of the grate, and
is of great service to the combustion. After a few tons of the oil
an; burned, this would Ijecome several inches in thickness, and
form a porous grate l)etter than any that could Ije uianulactiu'ed
for the i)urpose. — Mechanics' Magazine, Jan., 1866.

SIEMENS' REGENERATIVE GAS FURNACES.

Although this furnace has been described in the " Annual of
Scientific Discover}' " for 1804, the facts elicited are so important
and suggestive, that attention may be called to them again.
The points of special intc^rest are, 1st, the extremely high tem-
perature which can be obtained, and which, in fact, is limited
only by the nature of the materials employed in the construction
of the furnace ; and 2d, the possibility of emjjloying at Avill
either an oxydizing or a reducing atmosphere. The furnaces
have been applied to puddling and re-heating, and, no doubt, will
soon be extensively used in metallurgical processes. It is well
worth while to determine by direct experiment, on a large scale,
whether the rich iron ores of Lake Champlain, Lake Su2>erior,
and Missouri, cannot be directly reduced to tlie metallic state by
heating them to a sulliciently high temperature in the chamber
of a Siemens' furnace, and then clianging tlie gaseous mixture iu
the furnace to a reducing condition. This would, in fact, be
blooming upon a large scale, and would perhaps avoid the incon-
venience and expense of blooming in the small way, which, in
spite of the superior quality of the ii'on produced, has been almost
wholly superseded by the cheaper j^i-ocess of puddling. Exper-
iment only can determine whether fluxes can be used with ad-
vantage in blooming in this manner, when poorer ores are em-
ployed. Ores of co^jper could doubtless be roasted and reduced
in furnaces of this construction, and, with some additions to the
original plan, the sulphurous acid formed during the roasting
might be directly conveited into sulphuric acid in leaden cham-
bers. But it is for the metallin-gy of iron that the new furnaces
will probably be found most advantageous. As the temperature
attainable is exti'emely high, it may even be found practicable to
melt the malleable ii'on formed by the direct reduction of the ore,

MECHANICS AND USEFUL ARTS. 67

the walls of the fire-chamber Ijcino^ lined with lime, as more re-
fractory than tire-clay. But even if this should not be realized, it
is at least probable that the earthy impurities of the ore would be
reduced to a peculiarly fluid condition, so that the blooms could
be easily treated under the hammer and brought into the form of
malleable iron. TJiere is hardly a branch of manufacture in
which heat is emijloyed upon the large scale in which furnaces on
the regenerative principle would not find an application. Small
gas furnaces could Ije made upon the same ijrinciijle, for labora-
tory use and for various processes in the arts, using ordinary city
gas as fuel, instead of gas produced by a special furnace. The
high temperature obtained in Gore's gas furnaces appears to he
due to the heating of the air and gas before they mix in combus-
tion. — American Journal of Scietice, May, 1865.

SMOKE-CONSUMING APPARATUS.

M. Emile Martin, in a work published in London, in 1865, de-
scribes his improved steam-generating apparatus. The leading
idea is the use of two fire-places, and, therefore, doul^lc firing?
From the upper part of each fire-place tubular flues rise up to a
chamber within the boiler; from this chamber descend one or
more flues, at whose lower portion is a perforated grating of fire-
clay, on Avhich there is constantly kept a quantity of glowing fuel ;
below this is a space communicating Avith a chimney into'which
the products of combustion are exhausted by means of a fan or
other contrivance for producing a draught. In order to try the
plan, the Great Eastern Railway Company ajiplied it to an old
locomotive, working as a stationary engine at the Stratford sta-
tion. This old boiler, with M. INIartin's apparatus, was able to
provide with steam an engine of a hundred horse-power, and
Avith an economy of thirtj^-three to forty per cent, over the fifty-
horse boilers close by. These boilers are still in good condition,
and the advantage over them, obtained by the old locomotive-
boiler- furnished with this apparatus, seems mainly duo to the
consumption of smoke obtained by the latter. The work also
contains a report from two engineers, showing that, by means of
this arrangement, ten pounds of water were evaporated by the
use o{ only one pound of fuel, exclusive of the fuel used for
getting up steam. A new locomotive on this plan Avas in process
of construction. — London Mechanics' Magazine, Feb., 1865.

AMORY'S SMOKE -C0NSU3IING FURNACE.

Mr. Jonathan Amory, of Boston, Mass., who has devoted many
years to the perfection of a smoke-consuming furnace, has re-
cently issued a pamphlet on the subject, from Avhich the following
are extracts : —

" The subject of the economical application of heat for the pro-
duction of steam may be said, Avithout exaggeration, to be the
niost important for the consideration of every large manufiictur-
ing, agricultural, and mercantile community ; and one, too, the

68 ANNUAL OF SCIKXTIFIC DISCOVERY.

most iio2:loclorl, as far us ]n"acticn is ooncoriied. The cost of fuel
aiiiuially required iu the Uuitcd States for inoeliauical and mauu-
faeturiuii; ])urposcs, and princ'ii)ally for the generation of steam
(heaving out of the calcuhition the immense amount used in do-
mestie economy), has been estimated at $()0,000,(.)00. Estimating
it at only $oO,OUO,000, any improvement which would save even
one-quarter of this sum (or $12,500,000) would add so much M
tiie national wealth, In' largely extending man}' branches of pro-
ductive industry, and rendering prolitalile many cntm-prises now
languishing and poorly remunerative. The many different kinds
of furnaces and boilers now in use, in this country and in Europe,
like the many infallil)le cures for dangerous diseases, only show
that all are imperfect, and that no one is entitled to the full confi-
dence of the public.

"No one can deny tliat the prevention and consumption of
smoke are very desiraljle, both from a sanilai-y and an economical
point of view. The princi]}les of chemistry, and practical expe-
rience, show that the prevention of smoke and the perl'ect com-
bustion of fuel are S3"non}mous ; or, in other words, that smoke
is carbon escaping unconsumed from the ehimiKiy, and so much
lost fuel. Hundreds of tliousands of tlollars are thus annually
thrown away, at a time, too, when strict economy ought to be
the rule. It is not exaggerating to say that one-half of the fuel
used fur generating steam in this country would, with the use of
l^roper furnaces, perform the same service now derived from the
whole, as at present used.

" The idea that we cannot have fire without smoke is not true
of a well-constructed furnace, after the fire is once well kindled.
Man 3'^ attempts have been made to solve this smoke problem, but
all have failed, more or less completely, from inattention to the
laws of perfect combustion, the variable products according to
the fuel, the want of system in the management of the furnace,
and, above all, from the failure to bring the due iiroportion of
air into contact with the comljustible gases. Various devices have
been employed, both in Europe and this country, to arrest or
delay the gases of imperfect combustion in their passage to the
chimney, by different kinds of bridges, generally of fire-brick,
behind and near the fire ; and various imperfect attempts have
beeu made to admit a certain quantity of air behind these bridges,
to secure a more perfect combustion, diminishing, however, to a
certain extent, the heat by the admission of the cold air. Even
with these, in England, there has been secured a saving of thirty-
three per cent.

"As a preliminary to perfect combustion, a proper amount of
grate-surface, and a boiler of sufficient size, are of the first neces-
sity ; as, with too small a fire-surface, and a boiler so small as to
require constant forcing, perfect combustion and its resultant
economy are out of the question.'"

After showing the proper proportions of grate-bars to boiler-
surface, the heating properties of various kinds of fuel, and the
proper amount of ah* to be supplied for perfect combustion, he
goes on to say : —

MECHANICS AND USEFUL ARTS. 69

" la the best double-flued and double-furnaced English boilers,
about one square inch of permanent air-opening, behind the
bridge, is necessary for every square foot of grate-bar, — air pass-
ing as usual through the grate-bars from the ash-pit, and often
through holes in the furnace door. In the 'Amory' furnace, a
three to six-inch pipe is ample, (!onve3ing heated air to the cavity
of the curves, the ash-pit door (and the holes in the furnace
door, if necessary) being closed, after the fires have been well
kindled, — a very much less open air-space than in the best Eng-
lish furnaces. With an insufficient amount of air, if l)ituminous
coal or pine wood be used, the too-compact fire being suj^plied
only thi'ough the grate-bars, the gases pass quickly and uncon-
sumed through the flues, with a thick volume of dark smoke by
the chimney. Enough air only should be admitted to convert the
carbon of the fuel into carbonic acid by its oxygen, the hydrogen
being converted into water in the shape of vapor. In this con-
dition of a furnace, the products of combustion become invisible,
so that we may justly conclude that smoke is the measure and
gauge of imperfect combustion.

"Some turnace-makers admitted air through the furnace-doors
by a few large, or many small openings ; others, behind the bridge ;
but, in every case, cold air. In the ' Atiiory ' furnace, at a proper
distance from the fire, is placed a coml)ustion, or reverberating
chamber of concavo-convex hollow iron curves, concave toward
the fire, when a single one is used, and the length of grate-bars is
sufficient to admit the loss of so much fire-surface ; the curve on
the level of and just behind the fire; — concave toward each
other when two are used, above and at a greater or less distance
from the fire. Between the curved iron plates (best made of
boiler-plate one-eighth or one-sixth of an inch thick) is a hollow
space, communicating underneath with each, into which air is
received, heated b}^ passing through a pipe introduced through
the boiler, or otherwise, the air communicating with the fire-
chamber by several openings on the concave surfaces. It is also
necessary that the anterior curve be lower than the posterior,
to insure and facilitate the revolving of the gases in the chamber.

*' The principles of this furnace have for several years been
applied to locomotive, stationary, house, and steamboat furnaces,
with the most satisfactory results, as the testimonials appended
will show ; and it is confidently recommended to engineers, ma-
chinists, and builders, as meriting all that is claimed for it in
the saving of fuel and the consumption of smoke.

" This "furnace neither draws the air through the fuel by the
production of a partial vacuum behind it from high temperature
and rarefaction in the chimney, nor forces air through it by com-
pression, or other mechanical contrivance, before the fuel, — the
first exceedingly wasteful, and the second inconvenient and un-
necessary; but it secures a most perfect combustion and free-
dom from smoke, by the retention and reverberation of the gas-
eous products in a circular chamljcr, in which a due amount of
heated air is introduced, converting, in this way, much carbonic
oxide (usually escaping by the chimney) into carbonic acid gas,
and thus saving a great amount of caloric.

70 ANNUAL OF SCIENTIFIC DISCOVERY.

"The three jioints of the patent are, — 1st, Retention of the un-
coiisimii'd jrases, 2fl, Reverljonitiou by a eircuhir chamber of
l)roper rekitive heij2:ht in the two curves. 3il, A tlue s,upply of
heated air in the clianiber, and between its phites, doinj^ away
with (b-aft in front and from below, after the lire is once kindled,
afVordin;; safety from lire by closed furnaei! doors, freedom from
water which would put out the fires (l^y closed ash-pit), and i)re-
per\ation of iron in locomotives by the constant current of the
burniiii^ jjases in the chaml)er."

It is claimed that, by tiiis furnace, a savini; of twenty to forty
per cent, in fuel is cll'ected, and that with fuel even of the poorest
quality.

ON IRON SHIPS.

"Mr. "William Fairbairn communicates to the " Quarterly Journal
of Science," for April, bS(!(i, a paper on the loss of the "Londtm"
Steamsliip, Miiich foundered at sea on a voyage to Australia, from
which thi" foUowint^ an- extracts :

"The introduction of iron for the purposes of ship-building has
given greatly increased strength, and allbrded facilities for obtain-
iu<X new forms, which, aided by the power of steam, have insured
a rate of speed in vessels never before attained in naval histoiy.
It has, moreover, furnished the naval ai'chitect with a material of
immense value as regards construction ; and its careful distribu-
tion in the shajie of x'il)S, frames, and the sheathing of vessels,
cannot be too higldy api)reciated. As compared Avith the best
English oak, it exhibits four times its power of resistance ; and it
lias, in addition, the double advantage of being almost perfectly
homogeneous and free from the defects of open joints, which, in
tlie ciise of the planking of wooden vessels, require to be caulked.
AN'itii all these advantages, iron constructions are surrounded with
many dangers, when entrusted to the care and superintendence of
incompetent persons. In such hands there invariably exists a
want of pnjportion in the formation of iron vessels, which exhil^it
defective jiowers of resistance, and such other abnormal condi-
tions as might prove destructive to the efficiency and ultimate
security of the structure. It is of importance to take into account
the forms or lines of least resistance, such as a fine entrance at the
bows, and an equally clear run at the stern, if high sjieed is to be
obtained. The forms advantageous for vessels navigating rivers
and smooth water are not so in those intended for long sea-
voyages, and having to contend with the waves of the Atlantic. It
is "questionable, in the latter, whether or not some slight sacrifices
should be made to speed, and some modification eflected in the form
of the bows and stern, in order to meet all the requirements of a
safe and convenient vessel intended for the double purpose of
carrying passengers and cargo. The safety and success of a ves-
sel do not depend so much on its speed as upon its sea-going
properties and sound construction. If, for example, we take one
of the present iron clippers, with her sharp bows and fine propor-
tions, I am of opinion that she is neither the safest nor the best
description of vessel to contend with a heavy sea in foul weather.

MECHANICS AND USEFUL ARTS. 71

In the fiist place, she is a diver, which cuts into the sea and rises
with difficulty from a bath, which covers her decks Avith water as
she pitches from sea to sea. Repeated immersions of this kind are
exceedhigly uncomfortable to those on board, and cause the shij^
to lift some tons of water before her buoyancy is restored to meet
the next and every other succeeding wave into which she plunges
in a rolling sea. I think it is the duty of every ship-builder to
ajjproximate as closely as possible to the lines of least resistance,
which, in my opinion, ought to be carried to the utmost limits in
smooth water, but in smooth water only. It may not be out of
place to suggest that all passenger and emigrant ships should be
modified in their construction, so as to give increased displace-
ment at the bows and stern, but more particularly at the bows,
where they require bvioyancy, having to encounter the force of a
large body of water rushing over them and scouring the decks
from stem to stei-n. For several years I'have endeavored to im-
press upon the minds of naval architects the necessity of increased
strength on the upper deck of sea-going vessels, in order to bal-
ance the forces of tension and compression, and the double bottoms
on the cellular principle of construction. The ultimate strength
of a vessel is the resistance of its weakest part, and this being the
case, it is evident that it is of little or no value to have a strong
double bottom if the deck is liable to be torn asunder by the alter-
nate strains of a vessel pitching at sea. That these strains, often
repeated, lead to fracture does not admit of a doubt, and it has
been pi-oved by exi^eriment, that, under these circumstances, time
is the only element in the endurance of the structure ; and this
varies according to the intensity with which the strains are pro-
duced. I am convinced that heretofore the decks have been the
weakest parts, and that several iron vessels have broken right in
two from the ccMistant working of alternate strains at midships
along the line of the decks."

HYDRAULIC-LIFT GRAVING-DOCK.

Mr. Edwin Clark has described to the Institute of Ciyil Engi-
neers the plans adopted by him at the Yictoria (London) Graving-
Docks. The principle of these docks is to provide a single lifting
pit, out of which the vessels may be raised bodily on pontoons,
which afterward float them in shallow water to a convenient berth
for graving purposes. The shijos are raised by hydraulic presses,
the idea of which appears to have Iseen derived from the presses
employed in raising the Britannia and Conway Tubular Bridges,
designed under Mr. Clark's superintendence. At the Victoria
Docks, the depth of water in the lift-pit is twenty-seven feet ; that
over the rest of the dock is only six feet. In raising a vessel, one
of the pontoons is brought over the lift-pit, filled with water, and
sunk. The vessel is then floated in over the pontoon, and the
pontoon and .A^essel raised together by the hydraulic presses.
When at a sufficient altitude, the water is drawn oil from the pon-
toon, whic-h then, floats tlie vessel to its bertli in tlie shallow water.
The whole operation of lifting occupies only about half an hour.

72 ANNUAL OF SCIENTIFIC DISCOVERY.

and the lirtin<T:-pit is thou ready for the rccci^tion of another vessel.
At the Victoria Docks there are thirty-two i)resses, Avith ten-inch
rams, havinjx a stroke of twenty-live feet. This, with a water
pressure of two tons per circular inch, <^ives a total liftiufj,- power
of 6,400 tons, less the Weight of crosshead.s, rams, etc., amounting
to six hundred and twent}' tons. — Popular Science lieview, April,
18GG.

CORK SPRINGS.

The use of cork instead of Tndia-ruhher as a support for freight
cars and similar heavy vehicles, would not, a priori, seem very
l)romising, from ordinary impressions of its properties. The cork
used for such springs is of the commonest (U'scrii)tion, harsh, hard,
and full ol fissures ; it is cut into disks of aljout eight inciies diam-
eter, each pierced witli a central hole. Previous, liowever, to cut-
ting, it is s(jaked in a mixture of molasses and water, which gives
it some softness, and renders it permanently moist. A numl)er of
these cork disks are placed in a cylindrical cast-iron box, a flat
iron lid or disk is i)laced over them, and Ijy liydraulic; pressure is
forced down so as to reduce the thickness to one-half. A bolt is
then run through box, corks, and cover, at the centre, and a nut
being scrcAved on this holds all in jjlace, when the press is
relieved, and the box of compressed cork, disks, or cork spring, is
ready for use. One of these springs, placed in a testing machine,
under a weight of 20,000 pounds, showed an elasticity suggestive
of comiircssed air in a cond(>nsing pump. One would expect, from
the appearance of the material, that, under heavy pressure, it
would be pulverized or s\)\\i into shreds, especially if this pressure
was assisted bj' violent shocks; but, in fact, no such action takes
place. A pressun^ which destroj^s ludia-rubljer, causing it to split
up and lose its elasticity, leaves the cork unimpaired; and, with
the machinery in use, it has even been impossible, with any press-
ui'e attainable, to injure the cork, even when areas of but one
inch were acted upon. — Journal of Franklin Institute, May, 18G6.

ON THE PRESERVATION OF WOOD, IN DAMP AND WET PLACES.

In 184G, 80,000 sleepers of the most perishable woods, impreg-
nated, by Boucherie's process, Avith sulphate of cojjper, Avere laid
down on French railways: after nine years exposure, they were
found as perfect as Avhen laid. We Avould suggest Avashing out
the sap Avith Avater, Avhich Avould not coagulate its albumen : the
solution Avould appropriately folloAA'. Both of the last named
processes are comparatively cheap ; it costs less than creosotin^,
by one shilling per sleeper. The unpleasant odor of creosote is
o-reatlv against its use for lumljer for dwellings ; pyrolignite of
iron isofi'ensive, and also highly inflammable ; the aiTinity of the
chlorides for Avater keeps the structure into Avliich they are intro-
duced wet, and they also corrode the iron-Avork. Sulphate of
copper is free from these objections, and is cheaper than the
chlorides, and seems preferable for protecting wooden structures

MECHANICS AND USEFUL ARTS. 73

against dry rot in damp situations, like mines, vaults, and the
basements of buildings.

The surfoce of all timber exposed to alternations of wetness
and dryness gradually wastes away, becoming dark colored or
black. This is really a slow combustion, but is commonly called
wet rot, or simply rot. Other conditions being the same, the
most dense and resinous Avoods longest resist deeomiDosition.
Hence the superior durability of the heart wood, in which the
pores have been partly filled with lignin, over the open sapwood ;
and of dense oak and lignumvita? over light poplar and willow.
Density and resinousness exclude water; therefore our preserva-
tives should increase those qualities in the timber. Fixed oils
fill up the pores and increase the density ; the essential oils resin-
.ify, and furnish an impermeable coating ; but pitch or dead oil
possesses advantages over all known substances for the protection
of wood against clianges of humidity. According to Professor
Letheby ("Civil Engineers' Journal," vol. 23), dead oil, 1st,
coagulates albuminous substances ; 2d, absorbs and apjiropri-
ates the oxygen in the pores, and so protects from eremacausis ;
3d, resinifies in the pores of the wood, and thus shuts out both air
and moisture ; and 4th, acts as a poison to lower forms of animal
and vegetable life, and so protects the wood from all jsai-asites.
These properties specially fit it for impregnating timber exposed
to alternations of wet and dry states, as, indeed, some of them do
for situations constantly damp and wet. Dead oil is distilled from
coal tar, of wliich it constitutes about .30, and boils between 390°
and 470° Fahr. Its antiseptic quality resides in the creosote it
contains. One of the components of the latter, carbolic acid
(phenic acid, phenol) C^ H*^ 0^, the most powerful antiseptic
known, is able at once to arrest the decay of every kind of organic
matter. Professor Letheby estimates this acid at one-half to six
per cent, of the oil. BethelPs process subjects the timber and
dead oil, enclosed in huge iron tanks, to a pressure varying from
one hundred to two hundred pounds per squai'c inch, about
twelve hours : from eight to twelve pounds of oil are thus in-
jected into each cubic foot of wood. Lumber thus prepared is
not aftected by exposure to air and water, and requires jio paint-
ing. Four pence the cubic foot is estimated as the probable
exj)ense of this process.

Though we have not to guard against decay, when timber is
constantly wet in salt water, the Teredo navalis, a mollask of tlie
family Tubicolaria (Lam.) soon reduces to ruin any unprotected
submarine construction of common woods. None of our native
timbers are exempt from these inroads. The teredo never perfo-
rates below the surface of the sea-bottom, and probably does little
injury below low-water mark ; its food is the borings of the wood.
Poisoning the timber does not protect from the teredo, the con-
stant motion of sea-water soon diluting and washing away the
small quantity of soluble poison with Avhieh the wood has been
injected. Thorough creosoting the wood, with ten pounds of
dead oil per cubic foot, is a complete protection against the
teredo.

7

74 ANNUAL OF SCIENTIFIC DISCOVEKT.

Another destroyer of submarine wooden constructions is L'an-
noria terebrans, another nioilusk, resembling tlie sowbug*. It
pierces the liardest woods, and its perforations seem mei-cly to
serve as the animafs dwelliny-i)lace. The oidy successful pro-
tection seems to be the mechanical one of studding the surface
thickly with broad-headed iron nails; oxydation ra])idly iills up
the interstices I)etween the heads, and the outside of the timber
becomes C(jatcd Avitli an impenetrable crust, so tliat the ]jrest'nce
of the nails is hardly necessary. — Journal of the Franklin Insii-
tute, Nov., 1866.

METRICAL SYSTEM OF WEIGHTS AND MEASURES.

The subject of a decimal system of measure resolves itself into
twojiarts, — the desirability of a decimal sjstem, and the standard
of measure to be adopted as the unit; the first of which may now
be considered settled, and the principle delinitel}^ adopted in tliis
country, the use of decimal measures being now legalized by a
recent act of Parliament. But the second part of the subject, the
standard of measure, is still o])en, and is of very great impor-
tance ; the consideration of it involves two preliminary scieutilic
questions, and two practical conditions to ])e fullilled.

In i-esi^ect to the first scientific question, — as to the standard
that can be rei)laced best in case of Ix'ing lost, — tiiere is no rcjal
choice between the metre and the inch ; for the metre Iiaving I)een
originally detennined by measuring part of a quadrant of the
earth's circumference, its length was also referred to the seconds
pendulum for facility of repeating the measurement; and the
inch being obtaineil irom tlie seconds pendulum, both the metre
and the inch are thus verified by the same means: indeed, the
relation between them being once established, any means of
verification is equallj' availal)le for l)oth. In regard to tlie second
scientific question, — as to the standard that is most universal in
the character of its basis, — the supjiosed advantage of the metre,
as an even fraction of tlie quadrant, has been proved l^y the results
of mor(* accurate measurement to be a mistake, its actual length
being an uninen IVaction of the quadrant, just as tlie inch is an
uneven fraction of the pendulum ; and the length of the quadrant
itself being difl'erent in diilerent longitudes, there is therefore no
choice between the metre and the inch, in respect of universality
of its basis. The present legal standard of measure in this coun-
try is an individual metallic yard measure, independent of any
reference to another source ; and the metre is similarly a continu-
ation or copy of an original standard metre which is now known
to dilfer from the exact measure that it was intended to rei^resent
of the quadrant. There is no practical advantage, however, as
regards accuracy, in dependingupon copying for the preservation
of a standard ; for, by Mr. Whitworth's process of contact meas-
urement, the accuracy in copying lengths can now be carried as
far as one milliontii of an inch, which is a higher approximation
than can yet be attained in measuring the length of a j^endulum
or an arc of the earth's circumference.

MECHANICS AND USEFUL ARTS. 75

The fii'st practical condition to be fulfilled by the standard of
measure is that it shall be the one best suited for use in decimal
subdivision ; and this point is to be determined by the relative
jDractical convenience or inconvenience of its principal subdivi-
sions and multiples. In connection with mechanical engineering
work, the inch has a sjiecial qualification for the standard of
measure, since its subdivisions and multiples predominate in the
dimensions of the parts of machinery ; it is the basis on which
the various machines and engines made in this country have been
constructed, and on whicli are founded calculations of strength
of materials, sectional areas, steam pressure, power, velocity,
capacity, and weight ; so that the mechanical engineer may be
said to think in inches, calculate in inches, and work in inches.
For the classes of work in which the finer measurements are
required, such as rifle-boi-es, wire and metal gauges, etc., the de-
sired degree of accuracy is readily and conveniently expressed in
thousandths of an inch ; whilst the millimetre, the smallest subdi-
vision of the metre-scale, not being smaller than the one-twenty-
sixth of an inch, requires the addition of two places of decimals to
give tlie same degree of accuracy. This is a practical advantage
of importance in favor of the inch as the unit of measure, since
dimensions to one-thousandtli of an inch are now required in
regular use in mathematical work. Moreover, by taking as the
unit the lowest of the present denominations, — the inch, — any
longer dimensions on tlie present scale can be exactly expressed
in the decimal system witJiout fractional remainders. The second
practical condition attaching to the standard of measure is that it
shall be the one most extensively in use already, so as to involve
the least alteration of existing measures ; and, in addition to a
preponderance in the population now using the inch over that now
using the metre, the former includes the great machinery produc-
ers, whose worlc already exists in such large quantities in all parts
of the world, in the form of engines, macliinery, railway plant
and tools ; and the difficulties in the way of a change to the metre
in tins country appear, therefore, so insuperable, as to amount
practically to a prohibition of a decimal system, if it is to be based
on the metre.

For larger dimensions, the most convenient decimal change
would be the adoption of a ten-inch foot ; and the larger measures
being already multiples of the inch, their decimal adajjtation to
the inch would be at least easier than their entire alteration to the
metre standard. It is also very desirable that the present weights
and measures of capacity should be reduced to decimal systems ;
and it is considered that they can practically be based as readily
upon the inch, as the standard of measure, as upon the metre, in
the same way as with the definition of the metre or the inch.

In a discussion which followed the reading of this papei-, the metre
as the standard unit of decimal measure, in jirefei'ence to the inch,
was advocated by a deputation from the International Decimal
Association, who concurred in considering that the question of the
standard of measure depended upon the fulfilment of the practical
condition which had been stated ; that the standard should be the

76 ANNUAL OF SCIENTIFIC DISCOVERT.

one best snitod for use in decimal subdivisions, and the one most
extensively adopted already. As regarded decimal siilxlivision,
the results of inquiries made by the Association had led them to
recommend the metre as adai)ted for the greatest variet}' of mea-
surements, and for the most numerous cases likely to occur in
daily life, anil to conclude that the inch did not in itself oiler any
advantage above the metre, even to mechanical engineers, since
accuracy of measui'cment depended not on the scale, but on the
measuring instrument em])loyed, Avhich ought to be applicable to
any scale; and tiie millimetre had l)een already tried to some
extent in this countr\% and was Annul convenient and suitable for
mechanical work. In reference to the extent of population adojit-
ing the metn; or the inch, it was believed that the numerical i)re-
ponderance was already in favor of tlie former, and was steadily
increasing by the more general adojition of th(? metre in other
countries ; and the simplicity and convenience of the metre system,
both for measures and weights, were urged, together with the
great importance of facilitating international communications,
•which were now so much interfered with by the incongruity of
the systems in use. — Mu. John Feknie, of Leeds, in London
Mechanics' Magazine, February, 1865.

At the meeting of the National Academy of Sciences, held in
Washington, D. C., in January, 18GG, the Committee on Uniform
Weights, Measures, and Coinage, made the following report,
which was adopted by the Academy, and ordered to I)e conmnmi-
cated to the Treasury Department, and to the Congressional Com-
mittee having charge of the same subject: "The committee are
in favor of adopting ultimately a decimal system, and in their
oijinion the metrical system of weights and measures, though not
without defects, is, all things considered, the best in use. The
committee therefore suggest that the Academy recommend to
Congress to authorize and encourage by law the introduction and
use of the metrical s3-stem of weights and measures; and, with a
view to familiarize the people with the system, the Academy re-
commend that provision be made by law for the immediate manu-
facture and distribution to the custom-houses and States of metri-
cal standards of weights and measures ; to intr(;duce the system
into the ])ost-officcs, by milking a single letter weigh fifteen grains
instead of fourteen .and seventeen-hundredths, or half an ounce ;
and to cause the new cent and two-cent pieces to be so coined that
they shall weigh respectively five and ten grams, and that their
diameter shall be made to bear a determinate and simple ratio to
the metrical unit of length."

CONVERSION OF CAST-IRON INTO STEEL.

M. Galy-Cazalat, as reported in the " London Chemical News,"
No. 320, has communicated a new process for quickly and eco-
nomically converting any mass of cast-iron into steel, which he
accomplishes Ijy passing supei-heated steam into the fused iron.
In traversing the mass the steam is decomposed ; the oxygen
burns progressively the carbon and oxide of iron, while the hy-

MECHANICS A-ND USEFUL ARTS. 77

drogen coml^ines with and removes the sulpliur, phosphoi-us, and
other metalloids which render the steel brittle. When the color
of the tlarae at the top of the mass indicates a proj^er amount of
decarburation, the sLeel is run out. He operates either in a cupola
or a reverberatoiy furnace of his own construction, in which the
waste heat from the furnace is utilized to produce the steam.
There has always been a difficulty in knowing when to stop the
decarburating current, the process often being carried too far ;
but this author says common steel can always be regularl}^ pro-
duced by completely decarburating the cast-iron and then adding
ten per cent, of spathic cast-iron, which restores to the iron the
amount of carbon necessary to effect the conversion into steel.
By a peculiar contrivance, the author shuts off the current of su-
jjerheated steam from the metal and jaasses it into the chimney,
where it serves to increase the draft, and thus leaves the steel iu
a state of tranquil fusion for about fifteen minutes, by which he
gets a perfectly homogeneous mass. To remove bubbles in his
castings he has a very ingenious device. A cannon, for example,
being cast, while the inetal is still hot and soft, he covers the mould
hermetically with a sort of hat, from the top of which rises a pipe,
in which is placed six or ten grammes of a mixture of eighty parts
of saltpetre and twenty jjarts of charcoal. By opening a stop-
cock the powder is allowed to fall on the metal, where it gets
ignited, producing a large quantity of gas which exerts pressure
on all parts of the casting, removing the bubbles and increasing
the tenacity of the metal.

HARD AKD TUNGSTEN IRON.

M. Gaudin reports, that while experimenting in an ordinary
cupola furnace, by melting iron at a very high temperature with
phosphate of iron and peroxide of manganese, he succeeded in
obtaining a species of iron, very hard and forgeable, but turning
well, and applicable to the manufacture of jjieces which require
great strength and hardness. The metal is remarkably sonorous,
and might perhaps be applied to the casting of bells. A still
harder metal may be produced by the addition of tungsten to
ordinary cast-iron ; this tungsten-iron is said to surpass evisry-
thing previously known as a material for cutting rocks, and that
crystals of it will cut glass as easily as the diamond. — Jour.
Soc. Arts, No. 685, 1866.

SEPARATING PHOSPHORUS FROM METALS.

It is well known that phosphorus is a substance which prevents
the production of pure quahties of iron and other metals, and all
attempts to remove the same have hitherto tailed. Mr. Carl H.
L. Wintzer, of Hanover, has found that chlorine gas and chloride
of calcium are adapted to obtain the desired result. Chlorine
gas, as a simple element, does not decompose, and chloride of
calcium is the only combination thereof, wliich, at the different
7*

78 ANNUAL OF SCIENTIFIC DISCOVERT.

dcfifrees of temperature which occur in practical mctalhirgy,
neither volatilizes nor deconi])oses unless another agent be intro-
duced. Other known combinations of chlorine, as chloiide of
magnesiiftn, decompose even at the boilin;r-p<>int of water;
chloride of sodium becomes vohitile at a comparatively low tem-
perature.

Mr. Winlzor thororore employs chlorine p;as and chloride of
caleinni for the removal of i)hosj)horus, in i)roeesses of melting
ores and in the treatment of metallurgical products, lie makes
use of this gas and the salt in blast furnaces, as well as in the
])rocess of puddling, relining, and re-casting, and in an}- kind of
furnace and in all i)rocesses of melting, apphing the gas ilirect
or adding the prei)ared salt (chloride of calcium) in any con-
venient form; or, employing solutions containing muriatic acid,
with till! simultaneous use of lime or calcareous sul)stances, by
M'iiieh i»roeess chloride! of caleiiun is formed at tiie moment of its
ajiplieation. Through the elfect of chlorine gas and chloride of
calcium on i)hospliatic ores and metals, volatile combinations of
])hosphorus are formed, and therein' the phosi)horus is removed.
The process is as follows: In smelting an on; of iron or other
metal containing phosphorus as an impurity, the oj^erator charges
into the smelting-furnace, with the ore, chloride of calcium, in the
proportion of from live to twent\'-live parts, b}' weight, for each
part of pliosjjhorus found Ijy analysis to be contained in the ore;
and, in other resi^ects, the smelting operation, is conducted in the
ordinary maimer. The resulting metal will be found much more
free from phosphorus than if the ore had been smeltt^d without
the addition of chloride of calcium. In place of adding the
chloride of calcium direct, lime and muriatic acid may be mixed
separately with the ore, or may be otherwise applied in comljina-
tion. It is more convenient, however, to emjjloy chloride of
calcium ready formed. Or, in place of emplo3ing chloride of
calcium, cldoriue gas may Ije used ; the gas may be mixed with
air and forced as a blast through the ignited charge in the fur-
nace, or the gas itself may ijc blown through the melted metal
after it is tapped out of the furnace. The quantity of chlorine
thus applied should be from three to fifteen times the weight of
the phosphorus contiiined in the ore or metal. Chloride of calcium
or chlorine may l)e ajjplied in a similar manner when remelting
iron or other metals, when it is desired to sejjarate phosphorus
therefrom. Phosphorus can thus be separated from all metals
to which a strong red heat can conveniently be applied ; more
especially, however, it is applicable to the treatment of iron and
copijer. — Mecfianics' Magazine.

PURIFICATIOX OF IRON FROM PHOSPHORUS AND SULPHUR.

According to Dr. Adolphe Gurt, of Bonn, Prussia, iron may be
purified from phosphorus by means of silica. He asserts that if,
in smelting phosphoriferous iron ores, enough silica be included
in the furnace-charge to form a highly silicious slag, the phospho-
rus contained in the ore will have its condition changed from the

MECHANICS AND USEFUL ARTS. 79

ciystalline state, in which, he says, " it exists originally in the ore,
to an amorphous state, in which it is readily eliminated from pig-
iron during conversion either into malleable ii'on or into steel."
The same gentleman alleges that iron may be entirely freed from
sulphur by means of lead. The lead " may be applied," he says,
" either to pig-iron which is to be puddled, either before or during
the puddling process ; or to iron which is to be refined, or in
process of being refined, in common refinery furnaces, or in re-
verberatory furnaces ; or to pig-iron for casting ; or to iron to be
treated by the pneumatic process, for the production of either
homogeneous iron or steel ; or to the materials used in making
cast-steel by the jiot or other process of melting." In any case
the lead is to be added to the iron while the latter is in a molten
state, and is to be "brought by any suitable means as much as
possible into contact with the whole of the melted iron." — Me-
chanics' Magazine.

ON SODIUM AMALGAMATION.

Mr. Henry Wurtz publishes, in '• Silliman's Journal" for March,
1866, a communication on the process of sodium amalgamation,
discovered and patented by himself, which is of great practi-
cal value in metallurgy and the arts. His invention consists in
imparting to quicksilver a greatly enhanced adhesion, attraction,
or affinity for other metals and for its own substance, by adding to
it a minute quantity of one of the highly electro-positive metals
sodium, potassium, etc. It is applicable in all arts and opera-
tions in which amalgamation by quicksilver can be made avail-
able to separate or extract gold, silver, or other precious metals
from their ores — in all operations in which amalgamation by
quicksilver, in conjunction with reducing metals, such as iron or
zinc, can be made available in recovering metals from their soluble
or insoluble saline compounds ; such as silver from its sulphate,
chloride, or hypo-sulphate ; lead from its suljihate or chloride ;
gold from its chloride or other solution — in the mercurializa-
tion of metallic surfaces in general : for instance, in the amalga-
mation of the surfaces. of zinc in voltaic batteries; of the surfaces
of copper plates, pans, etc., used in the saving of gold from its
ores — in the more convenient transportation of quicksilver, by the
reduction thereof into solid forms.

From experiments made and reported by Prof. Silliman, this
discovery has proved of great value in the extracting of gold from
its ores. An interesting series of experiments with sodium-amal-
gam, in the treatment of auriferous ores, has been conducted under
the superintendence of Prof. Silliman, and the results obtained have
been highly satisfactory. He states that, having at his disjDosal a
considerable quantity of California gold quartz from a mine in Cal-
averas county, he proposed to Mr. Wurtz to subject these ores to
his method of amalgamation, under conditions subject to control,
both as expressing the actual value of the material experimented on,
as well as giving the value of the results and the loss in the process.
The crushing and grinding was effected in the apparatus of Mr.
Dodge, of New York ; which, doing its work dry, gives unusual

80 ANNUAL OF SCIENTIFIC DISCOVERT.

facilities for exactness. The details obtained in these experi-
ments, as to the degree of coninnniition readied by this apparatus,
have been very carefully worked out, but are reserved for a
future eoninninifaliun, having no bearing on the subject now
before us, although Ixdieved to be of value to the art of ore-
dressing. After detailing the several experiments which were
actually concludi'd, rrolt'ssor Sillinian observes, that the exper-
iments are still in progress, but the results show that, with un-
aided mercury, the gold saved is less than sixty per cent, of the
whole quantity of gold known to be present, in one experiment
less than forty per cent, was saved, while, by the aid of the amal-
gam of sodium the saving is increased to eighty per cent., or an
increase of more than twenty per cent., leading to the reasonable
expectation that, in the large way, at least eighty per cent, of the
gold present in a given case may be saved, and, in many cases,
where the golil is coarse and Iree, that even better results than
this may be attained. The fu-st experiment detailed, in which a
different amalgamating apparatus was used, gave results surpris-
ingly close. He does not tiiink the Ixirrel as good a form of ap-
l)aratus for this description of amalgamation as some one of the
numerous forms oi pan now in use. It was emplo3ed in these
experiments simplj' because it was a convenient means of treat-
ing small (iuantiti(!S of ore in making comparative experiments.
Experiments in California, muler his direction, have ijeeu set on
foot upon a scale of magnitude adequate to test the value of this
discoveiy, in the metallurgy of gold, in a satisfactory manner, the
results of which may now be looked for at no distant day. With
regard to the mode in which the sodium acts. Professor Silliman
remarks that the action of the sodium in this case ajipears to be
in a manner electrical, by placing the mercury in a highly elec-
tro-positive condition towards the electro-negative gold, seeming
to give some reason for the term magnetic amalgam, ado2)tcd by
INIr. Wurtz, as the trade-mark of the alloy. The quantity of
sodium is entirely too small to allow of the supposition that it
acts by its chemical affinities. It is well known to chemists that
the metallic sulphides are decomposed by amalgam of sodium ;
but no one supposes that an inventor could be found so Quixotic
in his chemical notions as to seriously propose the use of sodium
amalgam as a means of eftecting the reduction of the sulphides
af silver, etc., since not less than one equivalent of sodium would
be required to set at liberty one equivalent of silver. The use of
the sodium amalgam for silver amalgamation must depend, if
found really useful in the large way in the silver reduction
process (which still remains to be proven) , upon a like power of
electrical action to that seen in its action on gold, and also on the
well-known power of preventing the granulation (flouring) of
mercury, or on saving the mercury Avhen thus changed. Indeed,
there is good i-eason for believing that a most important part is
played by the sodium amalgam in this last particular. The amal-
gam of gold or silver is very liable, as eveiy mill-man knows to
his loss, to granulate and disappear from the plates of the battery,
or from the riffles, after it has been formed. If this granulation

MECHANICS AND USEFUL ARTS. 81

takes place, it is almost impossible, by the existing modes of
amalgamation, to recover the minute particles which float otf
with the currents of water, and ai-e lost. The action of the sodium
in recovering the mercury which has passed into this condition is,
perliaps, its most remarkable property. — Mining Journal, 18G6.

SODIUM AMALGAM.

This is now likely to be superseded by a far less expensive, and,
it appears, not less useful material. Caustic soda has not only
been found quite as effective as sodium amalgam, but it is contested
that the sodium in the amalgam actually assumes the form of
caustic soda before producing its ett'ect. A very simple experi-
ment will show the efficiency of the soda. If a finely pulverized
metallic powder is thrown into water, no amount of stirring will
cause it to fall to the bottom of the vessel ; it is rendered specifi-
cally lighter than the fluid by the coating of air which adheres to
it. But if a very small quantity of caustic soda or potash is added,
it will soon descend from the surface to the bottom. It is sup-
posed that the minute particles of mercury also, and of gold, are
prevented from coming into contact by a coating of air, which the
alkali removes in a way not yet ascertained. The jjotash or soda
must not be allowed to lose its causticity by exposure to the air,
or it will be ineflTective, having become a carbonate. — Intellectual
Observer, Sept., 1866.

SIMPLE MODE OF MANUFACTURING SULPHURIC ACID.

The necessity for large and costly leaden chambers has rendered
the manufacture of sulphuric acid both troublesome and expen-
sive. A method of producing it, in which the use of leaden
chambers is dispensed with, not only greatly facilitates the jjro-
cess, but affords a product which possesses the important advan-
tage of being altogether free from contamination by lead. Should
it be found to answer for industrial purposes, it will constitute a
very important improvement on the method so long in use. It
consists in transmitting the acid fumes, formed in the ordinary
way, through a series of earthenware cylinders, which are piled
up and arranged in such a way as to form a number of columns,
filled with coke, and communicating with one anotlier. Straw is
introduced into them as required ; and the acid vapors being con-
densed by the coke, they trickle down into a reservoir placed
beneath for the pm-pose of receiving them. The acid liquid thus
obtained is concentrated in the usual way.

NEW SAFETY LIGHT FOR COAL MINES.

MM. Dumas and Benoit have been making some experiments
in the French collieries on the application of electricity as an
illuminating power in " fiery" coal mines. Voltaic electricity has
been proposed on several occasions, as a means of giving light to

82 ANNUAL OF SCIENTIFIC DISCOVERY.

the collier in dangei'ous places ; but, undei* the onlinaiy condi-
tions, it has not been Ibund practicable to employ it. Dumas and
Benoit propose to apply lliiumkorff 's coil machine and Geissler's
tubes; to use, indeed, those tubes, with their beautilul auroral
light, as a miner's lamp.

The tube, it is now generally known, is fdled with some highly
rarefied gas, and platinum Avires are hermetically sealed into tlie
ends. AVhen tiie discharges Irom a Rliumkorir's coil apparatus
are passed through this tube, it becomes filled with a mild, difl'usive
light, which lasts as long as the discharges pass through the rare-
fied medium. This light is unaccompanied by heat; it cannot,
therefore, under any circumstances, explode the fire-damp of our
coal mines.

This new " safety lamp" consists essentially of a cylindrical zinc
vessel about six inches high and four inches in diameter, which
encloses a porous vessel holding a cylinder of carbon. A solution
of the bichromate of potash is placed within the ])()rous cell, and di-
lute sulphuric acid without it. This battery is secured by a wooden
cover, which is, by means of India-rubber packing, made to fit
closely. Then there are a Rhumkorfl"'s coil and condenser, and a
Geissfer's tube. This tube is arranged into a conical coil, so that
a large surface of light is secui*ed within a small space. Of course,
the oijjection to this will be the cumbrous character of the machine
and its adjuncts. Dumas and Benoit think tlu^y have answered
this objection by the very ingenious arrangement which they have
secured. We are assured that the weight of the glass case does
not exceed two pounds, and that of the other parts of the appara-
tus is not more than twelve pounds. That there are many advan-
tages in this electrical lamp cannot be denied. But we doubt if
so delicate a machine can be entrusted to the hands of colliers.
Under circumstances of danger, such a lamp as this would jjrove
of the highest value. As Dumas and Bcmoit are making practical
trials of their "cold light," as they call it, we shall, if they are
successful, hear more of this interesting^ipplication.

The Institute of France has given the inventors a pi-ize of one
thousand francs for the ingenuity of their jilan. We understand
that some trials have been made in the Newcastle collieries. The
ol)jection raised by the miners is, that the light is a "glimmer," —
not a steady illumination. — Reader.

HYDRAULIC 3(L\.CHINE FOR CUTTING COAL.

This machine, by W. E. Carratt, has now been at work for two
years. It does not dispense with labor, but it performs the under-
cutting, which was a most laborious operation, either in the end
or face of the coal, in a more efficient and economic manner
than the miner can do it himself. By it the size of the coal is im-
proved, the amount of slack reduced, and a single seam will
jdeld more by one thousand tons of coal per acre, than when
worked by hand-labor. The machine undercuts its "holes," or
"kirves," with one man and one boy as attendants, and comi^letes
the work, with once going over, at the rate of fifteen yards i^er

MECHANICS AND USEFUL ARTS. 83

hour. Each machine uses thirty gallons of water per minute, at
about three lumdred pounds pressure, according to the hardness of
the substance to be acted upon. The machine, when in operation,
fixes itself dead fast upon the rails during the cutting strike, and
releases itself at the back or return stroke, and traverses forwards
the requisite amount for the next cut without any manual laljor.
No percussive action results from the machine, either against
the roof or into the coal, but simply a concentrated pressure, pro-
ducing a stead}" recijirocating motion, at fifteen strokes per minute.
There is, consequently, no dust nor noise, and little wear and
tear. For the same reason, when cutting pyrites, the tools throw
out no sjjarks, and the Avorkmen can hear any movement in the
coal or roof. The price of a machine, a working model of which
is at the Industrial Exhibition, is stated to be £125.

STEAM FIRE-PROOF SAFE.

Rev. Rufus S. Sanborn, of Wisconsin, exhibited to the Massa-
chusetts Institute of Technology, in December, 1866, and described
a model of a steam fire-proof safe, of his invention. The nature
of this invention consists in placing one or more boxes, or unfilled
safes, one within the otlier, the outside case being filled or othei--
wise in the ordinary way, and these inner boxes detached from
one another and the outside case by means of flanges or spurs, so
as to form air-chambers all around said inside box or boxes, and
into these air-chaml)ers are inserted metallic vessels for holding
water, with simple steam-valves, which will be Oj^ened so as to
allorw the steam to escape when the heat of the inside of the safe
shall become sulficient for that jjurpose.

This steam saturates the air-chambers, and its surplus escapes
by the doors, so as to keep the tempei'ature of the inside of the
safe about that of boiling water, in which temperature none of the
papei-s of the inside box can either burn or char so long as any
steam can be maintained.

By a peculiar arrangement of a succession of these vessels, one
exhausts after another, and thus for a long time there is the most
complete protection, in addition to the other protection which the
filling and air-chambers aflbrd. He gave a history of the experi-
ments which had led to the above result, and stated that the safe
was soon to have a public trial. In an ordinary-sized safe, the
moist filling would save an hour in absorbing heat before the heat
could penetrate to the interior. Such a safe would hold fifteen
gallons of water, which, under the arrangement described, would
take a very long time for the entire escape of the steam.

At a trial held soon afterward, this safe was submitted to a heat
so intense as to melt the knobs on the door, and was kept exter-
nally red hot for nearly four hours : papers in the interior were
taken out entirely uninjured, and only a gill of water vaporized ;
while those in a safe by one of the best makers, submitted to the
same trial, were badly charred, as well as the whole interior wood-
work, and in another hour would have been destroyed.

84 ANNUAL OF SCIENTIFIC DISCOVERY.

A REMARKABLE SOLVENT.

It is now discovered, it appears, that if a piece of copper be dis-
solved in ammonia, a solvent will bo obtained, not only for lii^nine,
the most important principle of all woody fibre, such as cotton,
flax, paper, etc., bnt also for substances derived from the animal
kingdom, such as wool and silk. By the solution of any of these,
an excellent cement and water-proofer is said to be formed ; and,
what is equally important, if cotton fabrics be saturated with the
solution of wool, they will be enablcMl to take the dyes, such as
the lac dye and cochini'al, hitherto suited to woollen goods only.
Hydriodide of ammonia, we may also observe, was not long since
discovered to be an cipially remarkaide solvent of the most refrac-
tory, or, at least, insolulde mineral substances. Now it is an inter-
esting circumstance that ammonia, according to Van Ilelmont,
and other old chemists and alchemists, was one of th<! requisite
materials in the formation of the "alkahest," or "universal sol-
vent," of the ancient sages.

THE JL4GNESIUM LAMP.

A lamp for the pui-pose of burning the wire has been invented by
Mr. A. Grant. He sei-ks to make magnesinm cluiaper than the
best stearine, and statics that b}' Ijurning a strip of zinc in conjunc-
tion with two strii)S of magnesium, he is able to reduce the cost
of the light two-thirds. Il(! even predicts that magnesium will
become as cheap as zinc, and that in the course of time it will be
possible to illuminate a street a mile long at the rate of a half-
penny an hour, it is not a small thing to be able to record that
photography is no longer dependent upon tlu; action of the sun.
The value of magnesium as an illuminator for Ihv, })urpose of
" signalling" is ol)vious. The portable nature of the contrivance,
and its perfect immunity from risk of explosion, together with
some other evident advantages, render its vivid light all th(; more
practically valual)l(;. It may bo used with advantage on the
stage. — CivU Enyineers' and Architects'' Journal, Jan., 1865.

Four wires, weighing three grains per foot, each l)uruiiig at the
rate of eight inches per minute, or eight grains in that time, give
a light equal to two hundred and eightj-eight sperm candles, or
twenty-one and one-quarter Argand gas-burners. At this rate of
consumj^tion, one ounce of wire, costing six dollars and fifty cents,
would last an hour. — Franklin Journal, Now, 1865.

Several arrangements have been devised, more or less ingen-
ious, to burn the metal in the form of wire or ribbon ; but the
great difficulty in all such arrangements has been, that it required
clockwork to feed it forward. In order to avoid this difficulty,
]\lr. Larkin, after many trials, has succeeded in constructing a
magnesium lamp, a specimen of which we describe. The dis-
tinguishing peculiarity of these lamps is, that they burn magne-
sium in the form of powder, instead of ribl)on or wire ; and that
they do not depend on clockwork or any similar extraneous mo-

MECHANICS AND USEFUL ARTS. 85

tive-power for their action. The metallic powder is container! in
a lar2;e reservoir, having a small oi'ifice at the bottom, through
which the powder falls simply by its own gravity, like sand in an
hour-glass. In order that a sufficient orifice may be used, and to
facilitate the steady flow of the powder, it is mixed with a quan-
tity of fine sand or other diluting material, the proportion of pow-
der to sand being varied according to the amount of light re-
quired. After leaving the orifice of the reservoir, the stream of
metallic powder and sand falls fi-eely through a metal tube, into
the upper end of which a small stream of ordinary gas is also
introduced. The mingled streams of powder and of gas thus flow
down the tube and escape together at its mouth, where they are
ignited, and continue burning with a brilliant flame as long as
the supply of gas and metal is maintained. As the metal becomes
consumed, the sand with which it was mixed falls harmless into
a receptacle provided for it, while the fumes are entirely carried
away by a small tube-chimney into the outer atmosphere. Im-
mediately below the orifice, there is a valve, to either regulate the
quantity, or entirely arrest the flow of the metallic powder, which
valve may be opened and shut at pleasure. When it is desired
to light the lamp, the gas is first turned on, just sufficiently to
produce a very small jet at the mouth of the tube, which small jet,
being once kindled, may be allowed to burn any convenient time,
until the moment the magnesium light is required. All that is
then needed is to turn on the metallic'powder, which instantly de-
scends and becomes ignited as it passes through the burning gas.
This action of turning on and off the metallic powder may be re-
peated, without putting out the gas, as often and as quickly as
desired ; so that, in addition to the ordinary purposes to which
lamps are applied, an instant or an intermittent light of gi-eat
brilliancy, suitable for signals or for light-houses, may be very
simply produced with certainty of eft'ect, and without the smallest
waste of metal. Mr. Larkin explained that the lamp could be
made to suspend from the roof, in place of an ordinary gas sun-
liglit, and arrangements could also be made for its use in signals
and for light-houses. The greatest difticulty was the price of tlie
metal ; but only about four years had elapsed since the produc-
tion of the metal in any quantity by Mr. Sonstadt, and the
demand for it hitherto had been a fancy one. Mr. Larkin said
that the cost of burning magnesium in the lamp Avhich he exhib-
ited would, at its present price, be about £1 an hour, and that no
difficulty whatever was experienced in reducing the magnesium
to powder. — British Association Report, 1866.

PAKAFFIN FOR WATER-PROOFING.

About three years ago. Dr. Stenhouse took out a patent for ren-
dering leather and various textile and felted fabrics water-proof,
by means of paraffin ; it was found, however, that paraffin alone,
especially when applied to fabi-ics, became, to a considerable ex-
tent, detached from the fibre of tlie cloth after a short time, owing
to its great tendency to crystallize. The presence, however, of
8

86 ANNUAL OF SCIENTIFIC DISCOVERY.

even a small quantity of drying-oil causes the parafTin to arlhere
much more lirmly to the texture of the clotli, from tlie oil gradu-
ally becoming converted into a tenacious resin by absorption of
oxygen. Paraflin is now first molted with the requisite (juautity
of drying oil and cast into blocks; it can then be apjilied to fab-
rics, by rubbing tlicm over with a block of it, cither cold or
gtMitly warmed ; or the mixture may be melted and laid on with a
brusli, the comi)lete impregnation being elfected by subsequently
passing it between hot rollers. When applied to cloth tiuis, it
renders it very r(;j)ellant to water, though pervious to air. Cloth
paraflined in this manner forms an excellent basis for such arti-
cles as capes, tarpaulins, etc., which re(iuire to be made (]uite
inqx-rvious Ijy subseipiently coating them with drying-oil, the
l)arafiin, in a great measure, preventing the injurious inlluence of
drying-oil on the fibre of the cloth. The mixture can also be
very advantageously applied to the various kinds of leather ; one
of tli(» most convenient ways of efrecting this is to coat the; arti-
cles with the composition, and then to gently heat them until it is
entirely absorbed. When leather is thus impregnated, it is not
only rend(!red perfectly water-proof, but also stronger and more
durable; boots and shoes are 'rendered very firm without losing
their elasticity; it therefore not only makes them exceedingly
durable, but does not interfere with their polish, which, on the
Avhole, it rather improves. The superioritj'^ of paraffin over most
otluu' materials, ft)r some kinds of water-proofing, consists in its
comparative cheapness, in being easily applied, and in not mate-
rially' altering the color of fal)rics, which, in the case of light
shades and white cloth, is of considerable importance. — Practical
Mechanics' Journal, April, I8G0.

LINOLEUM MANUFACTURE.

The manufacture of this new and intei'csting material, which
threatens to ri\ al the India-rubber trade in the multiijlicity and
utility of its application, is based on the invention of Mr. Fred-
erick Walton, whose patents are now worked by the Linoleum
Manufacturing Company at Staines, and 45 Cannon Sti'cet, West.
The word linoleum is derived from linum (linseed) and oleum
(oil), from which products the new substance is made. The lin-
seed oil of commerce is solidified or "oxydized" by the absorp-
tion of oxygen, by which process it becomes changed into a semi-
resinous substance. It is then combined, at a strong heat, with
resinous gums and other ingredients ; and the substance thus
obtained has all the appearance and many of the properties of
India-rubber.

Those who are conversant with the uses of the pliable elastic
gums readily perceive the wide field of usefulness that any
material possessing such jiroperties is designed to occupy, more
especially as the price of the new substance is much lower than
India-rubber or gutta-percha. Linoleum can also be dissolved
into a varnish or cement in the same manner as India-rubber, and
m this form can be employed in the manufacture of material for

MECHANICS AND USEFUL ARTS. 87

water-iii'oof clothing. As a varnish or paiut for protecting iron
or wood, or for coating ships' bottoms, it is said to be admirably
adapted, as it dries rapidly, in fifteen or twenty minutes, and ad-
heres with singular tenacity. As a cement for uniting substances,
such as wood with iron, or wood with wood, it is very effective,
and has similar properties to the marine glue made from India-
rubber and shellac. Singularly enough, linoleum can also be
vulcanized or hardened by exposure to heat. By tliis means it is
made as hard as the hardest woods, and rendered capable of re-
ceiving a high i^olish without the aid of varnish or any other
extraneous substance. In this condition it can be filed, planed,
or turned as easily as wood, and employed in many of tlie vari-
ous ways for which wood is used. Or it can be moulded in heated
dies to any desired form, as, for example, flax-spinners' bosses,
sheaves for ships' blocks, surgical-instrument handles, picture
frames, mouldings, veneers to imitate marble, ivory, ebony, and
other woods. Combined with emeiy, it forms a grinding-wheel
having extraordinary cutting or abrasive power. Very dissim-
ilar are some of the uses to which the new substance can be
applied. Carriage-aprons, cart-sheeting, sail-covers, reticules,
tarpauling, printers' blankets, gas-pipes, telegraph supports,
washable felt carpets, table-covers, paints for carriages or for
printing floor-clotli, or enamels of any color for enameling pa-
pier-mache or metals. These are only some of the many uses to
whicli linoleum may be apjilied.

The manufacture has, however, hitherto been chiefly confined
to the develoj^ment of the floor-clotli trade, for whicli the new
material has proved itself well adapted. Linoleum floor-cloth is
produced by combining the linoleum with ground or powdered
cork, which is rolled on to a stout canvas, the back of the canvas
being afterward water-proofed with a cement or varnish made
from the solidified or oxydized oil, before referred to. The com-
bined fabric so manufactured is then printed by means of blocks,
in every variety of pattern, in the ordinary way. The floor-cloth
thus pi'oduced is pliable, and comiJaratively noiseless to walk ujion.
It washes well, preserves its color, and can be rolled up like any
ordinary cai-pet. Besides being very durable, — the comjjoncnt
parts being almost indestructible except by fire, — it will not de-
compose by heat or exposure to the sun or air, as is the case with
India-ruljber. It is therefore better adapted than that substance
for hot climates. To the chemist, engineer, and manufacturer,
linoleum ofters quite a new substance for experiment; and, no
douljt, as it becomes better known, the various uses to which it
may be applied will be more fully developed and appreciated.
The patentees, we understand, are prepared to grant licenses for
the manufacture of some of its applications, such as varnishes,
cements, and the hard compounds above mentioned. Important
results may, therefore, follow the introduction of this new and
valuable substance." — Mechanics' Magazine.

88 ANNUAL OF SCIENTIFIC DISCOVERY.

PARKESINE.

While considerable attention is being given to gun-cotton and
nitroleum, a somewhat similar substance is gradually making its
way as an article of orilinary domestic use, entirely free from
danger, and possessing sueh advantages as are likely to secure its
genrral adoption. In the manufacture of Parkesine, filjrous veg-
etable matter of any and every kind — cotton and llax waste, and
old rags, being, from their cheapness, the favorite materials —
may Ijc employed. These are first dissolved l)y acids, and they
then yield what chemists call pyroxyline. Pyroxyline, however,
as its name implies, is highly inthuninable, and indeed explosive,
like gun-cotton ; and this dangerous qualirjcation has to be neu-
tralized. Mr. Parkes effects this by the introduction of eitlier of
various chemical ingreilients, as iodide of cadmium, tungstate of
soda, chloride of zinc, gelatins, several carltonates, sulphates, and
phosphates. Collodion (as used by photographers), when evap-
orated so as to leave a solid residue, has Ijeen emplo3ed in the
production of Park<'sine ; but it was found l)y far too exi)ensive.
The substances which have given the best results with the pyroxy-
line are nitro-benzole, aniline, and glacial acetic acid. B}' the
use of various propinlions of these substances, all consistencies
of Parkesine, from the solid to the fluid form, may l)e obtained.
The applications of I'arkcsine are, of course, as numerous as its
forms are various. In the fluid form, it is availal^le for water-
proofing fabrics ; and in this way it is very serviceable. In a
plastic state, Parkesine is useful in making tubes, etc., and for
insidating telegrajih wires. Where hardness and toughness are
rcfiuired, these desiderata are aiTived at by the admixtui'c of oils
prepari'd with chloride of sulphur, which latter solidifies and
makes them (the oils) non-adhesive. Again, l)y the use of resins,
gums, stearin, tar, etc., modified preparations of the invention
may be made to suit special apj^lieations. Parkesine, indeed, is a
most accomodating material : and maybe made as hard and brittle
as glass, or as fluid and yielding as cream, and of every interme-
diate consistency. It may have elasticity imparted to it to almost
any extent or degree, and in this state it is likely to become a
dangerous rival to India-rubber and gutta-percha, inasmuch as it
will become, if it be not now, far cheaper than those useful arti-
cles of commerce, and answer almost all their uses equally well.
Vulcanized India-rubber will find a sturdy competitor in Parkes-
ine, for it may be manufactured with less of brittleness, quite as
much hardness, and at a lower cost than that tediously manipu-
lated substance. There is no refuse in the manufacture, the chi2'»s
and cuttings being cajjable of re-manufacture with the greatest
facility. Parkesine will take any color, and may be given any
degree of hardness ; it may be made to imitate tortoise-shell,
marble, malachite, or amber ; and can be cut with a saw, turned
in the lathe, planed, carved, engraved, stamped between dies,
rolled into thick or thin sheets, worked into screws, shaped into
mouldings or cornices, etc. It is suscei^tible of a high polish,
agreeable to the touch, and not disagreeable in smell. At a tern-

MECHANICS AND USEFUL ARTS. 89

peratiu-c of 340° Fahr., it is consumed, without flame, being decom-
posed and passing off as dense smoke, leaving but a dark colored
ashy residue behind. It is now being manufactured for a variety
of purposes, and is daily becoming more extensively known. — ».
Mining Journal.

At the 1865 meeting of the British Association, ]Mr. Owen Ro-
land read a jjajier on Parkesine. This substance derives its name
fi'om its inventor, Mr. Alexander Parkes, of Birmingham, Eng.
It is used for a great variety of purposes, and j^ossesses properties
akin to gutta-percha and India-rubber, and may be made easily
into any shajje and of any color. Gun-cotton is used in its manu-
facture as a basis ; but many other materials are also introduced,
solvents, oils, cotton-waste, etc. Cotton, not readily explosive, is
the most desirable ; chloride of zinc is also used to j^revent rapid
combustion. The solvent, invented by Mr. Pai'kes is apj^licable
cliiefly for India-rubber solutions, gutta-percha, and a number of
gums. The several varieties of Parkesine are made by mixing
these substances in definite pi'oportions. Mr. Roland considered it
more valuable as an insulating material thau India-rubber, gutta-
percha, or any other comljination hitherto used for this purpose.
It is enormously strong, being capable of supporting a mile of its
own weight, while it possesses the great qualification of Ijeing
joined, in case of fracture, with a strength equal to the original
substance. It is not affected even by acids ; and immersion in sea-
water four years did not deteriorate its qualities. In dry heat, at
212° Fahr., it remains electrically perfect, and it is not softened at
even a higher temperature.

INDIA-KUBBEE FOR MARINE CABLES.

At the Nottingham (1866) meeting of the British Association
for the Advancement of Science (Section of Physical Science),
Mr. Hooper read a paper on the electrical and mechanical prop-
erties of his India-rubber for submarine caljles. He reduces the
general coatings of India-rubber by means of heat to one perfectly
homogeneous coating, separated by a film of vulcanized India-
rubber. The advantages claimed are, durability and resistance to
mechanical injury, permanency of insulation at high temperatures,
impermeability under long immersion and pressure in water, free-
dom from defects in manufacture, and high state of insulation
Avith diminished induction. One hundred and fifty miles of this
wire have been sent to India, and the insulation per nautical mile
is about forty times better than that of the Persian Gulf core.

PAPER FROM WOOD.

•

The manufacture of white paper from wood is now quite a
success at the Manayunk Wood-pulp Works, Pennsylvania. The
wood used is that of the Liriodendron ^wZ/pZ/ej-a, Linn., in Tulip
poplar, and Abies canadensis, Michx, or Hemlock spruce. It is
brought to the works as ordinary cord- wood, and is cut into chips
by means of two immense machines having cutters attached to
8*

90 ANNUAL OF SCIENTIFIC DISCOVERY.

rotatniT discs, capablo. of cutting tliirty to forty cords of wood in
twenty-four hours. These cliips are conveyed in wagons to the
boiling-liouse, and placed in Ijoilcrs, wliere the I'eduction to pulp
is effected. The pulp thus reduciul is then conveyed to pulp-
engines, is worked in these engines, and run througli cleaning-
maciiines. From the cleaning-raacliines, the pulp is taken to the
bleaching-house. After having been l)leaciied, it is then ready to
be made into paper, in the same way as other pulp. Execlknit
"white jirinting paper, very good for newspapers, and at a prices of
three cents per jjound less than is charged for the same quality
of paper madi; from rags, is manufactured from this ])ulp at the
Flat-rock Taper Mills, adjacent to the pulp-works. The wood-
l)ulp must, however, be mixed with about twenty per cent, of
straw-pulp, this mixture improving the quality of the paper.
These works have been so successful that the jjricf! of pajxsr for
newspapers has declined three cents a pound since they have been
in operation. This is a very great step in the progress of those
arts which contribute so greatly to our comfort and civilization.

PROCESSES FOR PRESERVING MEAT.

In an official report laid before Pai-liament on the preparation
of beef in South America, for the English market, thret; methods,
proposed by Prof. JMorgau of the Renal College of Surgeons in
l)ublin. Baron Von Liei)ig of Munich, and Mr. Sloper of Lon-
don, are to effect this end.

Mr. ^Morgan's process is based on foi'ced infdtration, using the
circulatory s3-stem of the body as a means of introduction into the
tissues of the animal, by injection, as detailed in the "Annual
of Scientific Discovery" for lisGo, pp. 52-53. The process is simple
and efficacious ; by it an ox can hv preserved in ten minutes, using
from twelve to fourteen gallons of the fluid.

Liebig's jn'ocess differs essentially from the former ; for the meat,
instead of being preserved whole, is reduced to an essence, to be
used in making soups. The concentration is carried to such an
extent that thirty-three pounds of meat are reduced to one jjound
of essence, and the alimentary matter of an entire ox is contained
in eight pounds of this preparation, making over one thousand
basins of good strong soup.

It is a question of some importance whether cattle driven to the
pen in a semi-wild state, which are thrown into a violent state of
excitement on the approach of man, can afford nutntious meat,
and can be salted without parting with by far the greater portion
of such nutriment as they contain, and becoming almost valueless
as food, if not altogether unwholesome.

Another attempt is being made to bring to Eurojje the immense
supply of good meat wasted in South America. Mr. Liebert of
Hamburg has attempted the manufacture of Liebig's " extractum
carnis" at Fray Bentos, in Uruguay, and sends home about 4,000
pounds yearly. He is now iuci-easing his establishments, has con-
cluded a contract with the British Admiralty, and hopes soon to

MECHANICS AND USEFUL ARTS. 91

supply the extract at sixteen shillings a pound. Each pound is
tlie equivalent of one hundred and thirty pounds of meat, and will
furnish broth for one hundred and twenty-eight men. The ex-
ti'act in its best state is absolutely free from fat or gelatine, and is
now used veiy largely in continental hospitals.

The pi'ocess for preparing " extractum carnis," given in Lie-
big's " Familiar Letters on Chemistry," is as follows: Chopped
meat, deprived of all fat, is boiled for half an hour with eight or
ten times its weight in water, which suffices to dissolve all the
active ingredients. The decoction must, before it is evaporated,
be most carefully cleansed from all fat (which would become ran-
cid), and the evaporation must be conducted in the water-bath.
The extract of meat is never hard and brittle, but soft; and it
strongly attracts moisture from the atmosphere. The boiling of
the meat in the first instance may be carried on in clean copper
vessels ; but for the evaporation of the soup, vessels of porcelain
should be used. Liebig's j^rocess for making beef-tea is as follows :
Raw beef (recently killed) one-half pound, distilled water twenty-
two and one-half ounces, common salt fifty grains, dilute hydro-
chloric acid sixteen drops ; macerate the beef, chopped very fine,
in the water, etc., for an hour and a haK; strain ofl' through a fine
hair-sieve ; take two tumblers daily.

The following letter from Baron Liebig is taken from the " Lon-
don Lancet " : —

" Sir, — I see that rather contradictory views are expressed by
different English writers on the value of the extract of meat, some
taking it to be a complete and compendious sul:)stitute for meat,
whilst others assert that it has no nutritive value whatever. The
truth, as is usually the case, lies in the middle ; and as I was the
first who entered more fully into the chemistry of meat, I may be
allowed shortly to state the results of my investigations, as far as
the extractum carnis as a nutriment is concerned.

"Meat, as it comes from the butcher, contains two different
series of compounds. The first consists of the so-called albumi-
nous principles (i. e., fibrin and albumen), and of glue-forming
membi-anes. Of these, fibrin and albumen have a high nutritive
value, although not, if taken by themselves. The second series
consists of crystallizable substances, viz., creatin, creatinin, sarcin,
which are exclusively to be found in meat ; further of non-erys-
tallizable organic principles and of salts (phosphate and chloride
of potassium) . All of these together are called the extractives of
meat. To this second series of substances beef-tea owes its flavor
and efficacy ; the same being the case with extractum carnis, which
is, in fact, nothing but solid beef-tea, — that is, beef-tea from which
the water has been evaporated. Besides the substances already
mentioned, meat contains, as a non-essential constituent, a vary-
ing amount of fat. Now, neither fibrin nor albumen is to he found
in the extractum carnis which bears my name ; and gelatine (ghie)
and fat are purposely excluded from it. In the preparation of the
extract, the albuminous principles are left in the residue. This
residue, by the separation of all solulde principles, which are
taken up in the extract, loses its nutritive power, and cannot be

92 ANNUAL OF SCIENTIFIC DISCOVERY.

mailo an nrticlo of trado in any palatal>lo form. Were it po?;siT)le
to fiu-nish the market at a reasonable price with a preparation of
meat coml)ining in itself the albuminous toj^ether with the ex-
tractive principles, such a preparation would have to lie preferred
to the extractum carnis, for it would contain all tlie nutritive con-
stituents of meat. But there is, I think, no prospect of this being
realized. Hap2)ily, the albuminous principles wanting in the ex-
tract of meat can l)e replaced by identical ones derived from tho
vegetable kingdom, at a much lower price. Just the reverse is
the case in regard to tiie extractive matters of meat, for (tiieir
salts excepted) it is impossible to find any substitute for them.
On the other hand, tliey may be extracted from the meat, and
brought into the market in a palatable and durat)le form. In con-
junction witli all)unnnous principles of vegetable origin they have
the full nutritive cllect of meat. From the extractive matters, then,
contained in extractum carnis in a concentrated form, the latter de-
rives its value as a nutrin)ent for the nations of Europe, provided
it can be prcxluced in large quantities and at a cheap rate from
countries where meat has no value.

"The all)uminous principles of vegetable origin are principally
to be foiHid intiie seeds of cereals; and the European markets are
suflicicntly provided witii them. On the; other hand, the supply
of fresh meat is insufficient ; and this will get worse as the popula-
tion increases. For an army, for example, it will not be difficult
to provide and store up the necessary amount of gi*ain or flour.
Sugar, too, as well as fatty substances and tlie like, will l)e procur-
able, their transport and preservation offering scarcely any diffi-
culty. But there may easily occur a deficiency of fresh meat.
Salted meat but inadequately replaces fresh meat, because, in the
process of salting, a large quantity of the extractive principles of
the meat is lost ; besides, it is well known that those Avho live on
salt meat for a continuance become subject to different diseases.
Dried meat generally means tainted meat, scarcely eatable. Ex-
tractum carnis, combined with vegetable albumen, enables us to
make up the deficiency ; and that combination is the only one at
our disi^osal. What was said of an army also holds good of those
European nations in general that do not produce a sufficiency of
meat. By making tiie most of the hei'ds of South America and
Australia, in using them for the preparation of extractum carnis,
and Ijy the importation of corn from the West of the United States
and other corn-growing counti'ies, the deficiency may be made
up, although not to the full extent. For, supposing ten manufac-
tories, producing together ten million pounds of extract of meat
from a million oxen or ten millions of sheep, that whole quantity
Avould provide the population of Great Britain only with one
pound yearly for every three persons ; that is, one jiound a day
for every eleven hundred persons.

" I have before stated that, in preparing the extract of meat,
the albuminous principles remain in the residue : they are lost for
the nutrition, and this certainly is a great disadvantage. It may,
however, be foreseen that industrial ingenuity will take hold of
this problem and solve it, perhaps by a circuitous road. For if

MECHANICS AND USEFUL ARTS. 93

this residue, together with the bones of the slaughtered beasts,
be applied to our fields as manure, the farmer will be enabled to
produce a corresponding quantity of allniminous principles, and
to better supply our towns with them, eilhtn- in the shape of corn
or of meat and milk. ]\Iade into a marketable state, it may here-
after replace the Peruvian guano, Avhich very soon will disappear
from the market.

" On the value of extract of meat as a medicinal substance, it
is unnecessary to say a word, it being identical with beef-tea,
about the usefulness and efficacy of which Opinions do not differ.
At the same time, I may remark that it is a mistake to think that
beef-tea contains any albumen, that there ought to be any gela-
tine or droits of fat to swim on its surface. Beef-tea does not
contain any albumen, and, if rightly prepared, ought to be free
from gelatine (or glue), whilst the supernatant drops of fat form
a non-essential, and, for many, an unwelcome addition.

" I should be glad if these lines could assist in clearing up pub-
lic opinion on the value of exti-act of meat as a nutriment ; my
aim being, on the one hand, to reduce to their right limit hopes
too sanguine ; on the other, to point out the true share which the
extract of meat can have in the nutrition of the people of Europe.
In doing this, I know full well that whatever may be said for its
recommendation would be in vain, if the extract of meat did not
supply a public and generally felt necessity, and if it could not
stand the test of our natural instinct, — a judge not to be bribed.
*' I am, sir, your obedient servant,

"Justus Liebig.

"Munich, November, 1865."

In a letter to the "London Journal of Pharmacy," written by
Liebig, the following remarks occur: —

" It has been observed that the color and taste of the Fray Ben-
tos Extract vary ; this is owing to the difference of sex and. age
of the animals. °

" The meat of oxen always yields an extract of darker color
and stronger flavor, reminding somewhat of the flavor of fresh
venison — pleasant when diluted. The extract of cows' meat is
of lighter color, and a mild fla\'or, and is preferred by many per-_
sons. The meat of animals under four years cannot be used for'
the manufacture of extract ; it yields a pappy extract of weak
taste, like veal, and without flavor.

" According to the predominance of ox or cows' meat, the color
and taste of extract varies, which is by no means a fault of the
manufacturing process, and is fully explained by the preceding
remarks. The extract of ox meat is, however, richer in creatinin
and sarcin than the cows' meat extract.

"It is extremely difficult, as regards extracts of meat, — the
genuineness and purity of which are not discoverable by the eye,
— to protect the puljlic against fraud. All manufacturers prepare
their extract according to what they call ' Liebig's process ; ' but
since I have given only general, and not special, directions for
manufacture, it so happens that every one fiJls in the details after

94 ANNUAL OF SCIENTIFIC DISCOVERT.

bis own fashion, and the consequence is that not one of these
extracts is, in its composition, like another.

" Tliere exist only two si^ecial directions for the manufacture
of extract of meat, — tiie one in the " Bavarian Pharmacopceia," the
other in the "riiarmacopoeia Gcrmauica" ; but these directions are
not mine.

''Munich, 22d October, 186G."

The remaining process, patented by ;^^essrs. McCall & Sloper,
professes to preserve meat in its fresh or raw state, arriving at
mai'ket in tiie exact condition of butchers' meat just killed, but
with an additional advantage of keeping twice as long as ordi-
nary meat, after being exposed to the air.

The following is a co])y of the specification taken from the
English Patent Ollicc, and published in the "Scientific Amer-
ican " : —

" Our improvements relate to preserving fresh meat, poultry,
game, and lish. AV^e treat such food in one or other of the fol-
lowing methods : We immerse in or surround the meat for a
short thue, say from ten to fifteen minutes, more or less, with a
solution of Ijisiilpliite of soda or potash, in the case or vessel in
which it is to be preserved, and wliich must be cai)able of being
made air-tight. By this immersion we remove the air which
filled the vacant sjjaces in the case ; we then withdraw the solu-
tion and replace it by carbonic acid gas. AVe repeat these immer-
sions and supplies of gas occasionally, as required. We introduce
into the case containing the food a regulated quantity of dilute
sulphurous acid, and an etpiivalent quantity of carbonate or bicar-
bonate of soda, or potash, soparatel}'. The acid and alkaline salt
do not come into contact until the case is hermetically closed,
when they are brought into contact by agitation, and the liquid
resulting, chai-ged Avith carbonic acid, batlies the surface of, and
impregnates tlie meat ; or the acid and salt may be brought into
contact before the case is closed ; or we place the meat in a case
jDrovided with two stop-cocks, one in or near the bottom, the other
in the lid. By the lower stop-cock we introduce a solution of
bisulphite of soda or potash, filling the vacant spaces in the case ;
we then close the stop-cock in the lid, and exhaust the case of its
liquid contents by powerful hydraulic suction, or by the action of
an air-pump. We leave the meat under this exhausting suction,
and thus draw out from the meat as much air as it will yield up,
which we then expel from the case by the introduction of a solu-
tion of bisulphite of soda or potash, which we afterward with-
draw and replace by carbonic acid gas. We repeat, at intervals,
these alternate introductions of the alkaline solution and carbonic
acid gas.

" When metallic cases are used either for preserving or packing
the food, we use a lining both for the top, bottom, and sides, of a
non-metallic nature, such as thin matting, wickerwork, veneers of
wood, cloth, or other suitable materials.

" We preserve poultry, game, and fish, in the same manner as
that described for meat.

MECHANICS AND USEFUL ARTS. 95

'* And having now described the nature of our said invention,
and in what manner the same is to be performed, we declare that
we claim as our improvements in preserving fresh meat, poultry,
game, and fish, —

"First, the employment of bisulphites of soda and potash, sub-
stantially in manner hereinbefore described.

" Second, the process hereinbefore described, whatever the anti-
sei^tic salt employed .

" Third, the employment of an alkaline salt, together with car-
bonic acid, or the substances producing the same, sulphurous acid
and carbonate or bicarbonate of soda or potash, acting in manner
hereinbefore described.

" And we claim as our improvement in the vessels employed in
preserving fresh meat, poultry, game, and fish, by any of the
methods hereinbefore described, the lining of the same with mat-
ting, wickervvoi'k, or other like suitable material, to protect the
substance being preserved from contact with the vessels."

ON PAPEK FROM COEN FIBRE.

Chevalier Von Welsbach, Director of the Imperial Printing and
Paper-Making Establishments at Vienna, Austria, has brought the
process of paper-making from corn fibre to gi'eat perfection. It is
claimed that the paper thus made is stronger than cotton or linen
paper of the same weight ; that in hardness and fineness of grain
it exceeds the best hand-made English drawing-paper ; that it is
more durable than any other paper, and is not, like parchment,
subject to be destroyed by insects, thus rendering it peculiarly
valuable for documents, records, etc. ; that it is unsurpassed for
ti'acing-pajjer, and can be made extremely transj^arent, and is
siDccially adapted for photography. It is also claimed that all
papei'S ordinarily made from cotton and linen rags can just as well
be made from this material ; that it can be easily converted into
the finest writing and printing paper, and almost as advantage-
ously into superior stout wrapping-paper. It readily receives any
tint of color.

GELATINE FEOM MARINE PLANTS.

M. Natalis Rondot made to the Society for the Encouragement of
National Industry, at Paris, a communication on the subject of the
marine plants from which the Chinese procure gelatine, either as an
article of food or for use in the arts. The subject seems to demand
attention from us, both as a means of reducing the jirice of a valu-
able article of diet, and as a means of introducing cheaj^er substi-
tutes for materials of which the large consumption in the arts is
raising the price seriously. The same families of plants inhabit
our coast, and doubtless gelatine, as delicate in flavor, and as
sti'ong, could be easily and cheaply prepared from them.

96 ANNUAL OF SCIENTIFIC DISCOVERT.

rMrROVEMENTS IN DYEING.

*

New Apph'rafion of Tannin. — Not only are now anillno dyps
constantly disoovorofl, but now and more eonvoniont or oiTeclive
modes of applying them are obtained. Silk and wool are easily
dyed by means of them; vegetable matters, the affinities of which
for colors of all kinds are much weaker, not so c^asily nor so
ettbctively. It has hov.n discov(!red, however, tliat brilliant colors
may be imparted to flax or cotton by means of the aniline,d3^es, if
they are Ih-st impregnated with an alkaline solution of tannin.
Vegetable parchment, which acts like silk or wool with reference
to the aniline dyes, does notre(|uiro the use of tannin. When ordi-
nary paper is to be colored, the tint ol)tained is wonderfully im-
proved if it is coated with albumen before being subjected to the
action of tannin.

Utilization of Aniline Djiat. — The beautiful colors derived from
aniline have already received a very general api)lication ; Ijut they
have been, hitherto, unsuitable to one pur])oso, which would be most
likely to Ijeneflt by the brilliant elFects they produce, — oil paint-
ing. They are now very likelj' to become extrouKdy useful in
this branch of art. It has been found that a solution of aniline is
capable of dissolving caoutchouc, and all the x-esins which have
acid properties, and also the aniline dye-stuffs. Tlie solution of
shellac, for example, in aniline, may be colored by the addition of
the concentrattul solution of aniline dye-stutf; the result being a
transparent paint, which answers admirably for glass, porcelain,
etc. This shellac solution may be mixed with any oil 2)aints that
contain no lead ; and thus an oil paint of extraordinary l)rilliancy
may be obtained. With the exception of fuschine, all the aniline
dyes may be dissolved in the aniline solution of shellac itself.

Aniline. — It requires as many as two thousand tons of coal to
produce a small circular block of aniline twenty inches liigli l)y
nine inches wide. This quantity is sufficient to dye three hundred
miles of silk fabric.

Aniline Black. — The discovery of a fine black, pi'oduced from
aniline, may almost be considered as completing the series of
magnificent colors obtained from that substance. This new dye
is the more valuable, since it may be associated with any kind of
madder color, and may be treated in subsequent processes like
logwood. It is obtained by dissolving hydrochlorate of aniline
in an aqueous solution of hydrofluosilicic acid (sjiec. gi-av. 8° B.)
which has been projierly thickened, and then adding chlorate of
potash, and printing or preparing the tissue with chlorate of pot-
ash, and afterward printing. On raising the temperature from
32° to 35° C, a beautiful and permanent black is produced. The
hydrofluosilicic acid required may be obtained by decomposing
a mixture of fluor-spar and sand with sulphuric acid. The
decomposition which takes i)lace during the process consists in
decomjjosition of the chlorate by the hydrofluosilicic acid, silicate
of potash being formed and chloric acid set free. A part of this
chloric acid acts on the hydrochloric acid of the hydrochlorate of

MECHANICS AND USEFUL ARTS. 97

aniline, forming a mixture consisting of free chlorine and inter-
mediate oxygen acids of chlorine ; and the remainder unites with
this mixture, forming the black dye.

NITKOGLYCEEINE.

Nitroglycerine is the product of the reaction which ensues when
glycerine is slowly poured into a mixture of concentrated nitric
acid, Avith twice its bulk of oil of vitriol. The glycerine loses
three equivalents of water, which are replaced by three of nitric
acid. It has been called also trinitrine, triiiitro-glycerine, etc.

It is a liquid of specific gravity 1.6, nearly insoluble in water,
easily soluble in alcohol and ether. It has great stability, and
keeps indefinitely ; foreign bodies do not favor its decomposition ;
at ordinary temperatures it even remains unchanged in presence
of phosphorus and jjotassium. It does not explode by flame ;
burns by contact with an ignited body, but ceases to burn as soon
as the contact is at an end. It explodes only at 860° Fahr. It
detonates by a violent blow of a hammer, but only the part sub-
mitted to the blow explodes, without action on the surrounding
liquid. Its principal advantages in blasting in mines are, 1st.
Being insoluble in water and heavier than it, it can be used in
wet mines and under water. 2d. Not exploding by contact of
an ignited body, unless strongly compressed, it may be carried,
kept, and handled without danger. 3d. Its expansive force
being ten times greater than gunpowder, it economizes labor.
4th. The rapidity of its exiilosion renders tamping of no im-
portance, and thus renders the miner perfectly safe. 5th. It is
as efficient in a soft and crumbling stone as in a hard and com-
pact one ; it leaves no residuum. — Annales dn Genie Civil.

It is an oily fluid of a light yellow color, and of 1.6 specific
gravity. It consists of 3 atoms of nitric-acid, or 3 NO5, com-
bined with an atom of glycerine, C^ H^ O^, so that its ultimate
composition may be represented by C^ H^ Ois N. The changes
which occur during explosion convert each volume of it into 469
volumes of carbonic acid, 654 volumes of steam, 39 volumes of
oxygen, and 236 volumes of niti'ogen, being a total of 1,298 vol-
umes of gas for each volume of the liquid oil, being thus five
times more efi'ective than its bulk of gunpowder ; but from the
greater amount of heat generated, and the consequent higher
tension of the gases produced by the explosion, the new agent is
really thirteen times more effective, bulk for bulk, and eight times
more effective, weight for weight, than gunpowder, resulting, for
blasting puri^oses, in very great economy of labor. — London Me-
chanics'' Magazine, September, 1865.

The explosive properties of nitroglycerine C^ H^ (N 0)i Os, and
the accounts of experiments made with it in dift'erent parts of
Sweden, Germany, and Switzerland, determined MM. Schmitt
and Dietsch, the proprietors of the great quarries of sandstone in
the valley of Zorn, Lower Rhine, to try to use it in their works.

The trial proved so successful, l^oth as regards economy and
the ease and rapidity with which the work was performed, that,
9

98 ANNUAL OF SCIENTIFIC DISCOVERT.

for the time, at least, they have abandoned the use of powder, and
the quarries have been entirely worked by nitroi^lycerino for six
weeks.

From the first, we have considered that the nitroglycerine sliould
be pi-ejiared on the spot. It always seemed to us the transportation
of an explosive compound of sucli frightful i)ower ought not to be
allowed either by laud or watei*. Tiie terrible accidents which
have happened at Aspinwall and at San Francisco justify these
fears; and the transportation of nitroglycerine should be posi-
tively forljiddi'U.

After having, with M. Keller's assistance, studied in my lal)ora-
toi-y the ditfcrent processes of the prciparatiou of nitroglycerine
(mixtures of glycerine with concentrated sulphuric acid and
nitrates of potash and soda, or with nitric aiids of dilferent concen-
trations), we have determined on the following method of manu-
factm-e, which is performed in a wood cabin, constructed in one
of the quarries : —

Preparation of Nitroglycerine. — We begin by mixing in an
earthenware vessel placed in cold Avater some fuming nitric acid
at 49° or 5U° Baume (1.51 — 1.53) with twice its weight of the
strongest sulphuric acid. Tliese acids are purposely prepared at
Dieuze, and sent on to Saverne. At the same time, we evaporate
in a pot some commercial glycerine free from both lime and lead,
until it makes 30° or 31° Baume (1.26 — 1.27). This concentrated
glycerine should, after cooling, have a syrupy consistence.

The workman then tlu'ows thirty-three hundred grammes of a
mixture of suli)huric and nitric acids, well cooled, into a glass fiask
(a pot of earthenware or a capsule of porcelain might equally be
employed) placed in a trough of cold water, and then he slowly
pours into it, stirring it continually, five hundred grammes of gly-
cerine. The thing to be observed is tlie avoidance of any sensible
heating of the mixture, wliich would determine a tumultuous
oxidization of the gh'cerine, and the production of oxalic acid.
For this reason it is, that the vessel in whicli the transformation of
the glycerine into nitroghcerine takes ^^lace should be constantly
cooled externally by cold water.

When the materials ai"e thoroughly mixed, the whole must be
left for five or ten minutes ; then pour the mixture into five or
six times its volume of cold water, to which a rotatory movement
must first be imparted. The nitroglycerine precij^itates very
rapidlj', under the form of a heavy oil, which is collected by
decantation into a vessel ; then wash it with a little water, which
is in its turn decanted ; pour the nitroglycerine into bottles, and it
is x-eady for use.

In this state, the nitroglycerine is still slightly acid and watery ;
but this is of no importance, since, as it is emj^loyed soon after
its preparation, these impurities in no degree prevent detonation.

Properties of Nitroglycerine. — Nitroglj-cerine is a yellow or
brownish oil, heavier than water and insoluble in it, but soluble
in ether, alcohol, etc.

Exposed to a prolonged but not intense amount of coldness, it
ci-ystallizes in long needles. A violent shock best causes it to

MECHANICS AND USEFUL ARTS. 99

detonate. The handling of it is now easy, and only slightly
dangerous. Spread upon the ground, it is only with difficulty
fired by a body in combustion, and then only burns pai-tially ; a
flask containing nitroglycerine may be broken upon stones with-
out its detonating ; it may be volatilized without decomposition
by a regulated heat ; but if it boils, detonation becomes imminent.

A drop of nitroglycerine falling on a metal place moderately
heated volatilizes quietly. If the plate be red-hot, the drop is
immediately fired and burns like a grain of powder, only noise-
lessly ; but if the plate, without being red-hot, is hot enough to
make the drop boil immediately, it decomposes suddenly with a
violent detonation.

Nitroglycerine, especially when impure and acid, decomposes
S]5ontaneously after a certain time, with an escape of gas and the
production of oxalic and glyceric acid.

Probably the sjiontaneous explosions of nitroglycerine, with
whose disastrous effects the i^apei'S have acquainted us, are owing
to the same cause. The nitroglycerine being inclosed in well-
corked bottles, the gases produced by its spontaneous combustion
cannot escape ; they then excercise an immense pressure on the
nitroglycerine, and in this state the least shock and the slightest
movement will cause an explosion.

The flavor of nitroglycerine is at once sweet, piquant, and
aromatic ; it is poisonous, and taken in small doses it produces
bad headaches. Its vapor produces similar efi'ects, and this reason
might well prove an objection to its use in the subterranean gal-
leries of mines, where its vapors cannot disperse as they do in
oiDen-air quarries.

Nitrogl}^cerine is not, properly speaking, a nitrated body, such
as uitro- or binitro-benzol, or mono-, bi-, and trinitro-phenisic
acids. Indeed, under the influence of reducing bodies, such as
nascent hydrogen, sulphuretted hydrogen, etc., the glycerine is
set at liberty, and the caustic alkalies decompose the nitrogly-
cerine into nitrates and glycerine.

Modes of Employing Nitroglycerine. — Suppose the object is to
detach a stratum of rock^ At 2.50 to .3 metres distance from the
exterior border, sink a mining hole about 6 or 6 centimetres in
diameter, and 2 or 3 metres in depth.

After having thoroughly cleared all mud, water, and sand out
of the hole, pour into it, through a funnel, from 1,500 to 2,000
grammes of nitroglycerine. Then immerse in it a little cylinder
of wood, pasteboard, or tin, about 4 centimetres in diameter, and
from 5 to 6 centimetres in height, and filled with ordinary pow-
der. This cylinder is fixed to an ordinary mining fuse, which
goes down a certain depth to insure the combustion of the pow-
der. The cylinder is lowered by means of the wick or fuse ;
the moment the cylinder reaches the surface of the nitrogly-
cerine may easily be known by the touch. When it touches
the surface, hold it perfectly still, and pour sand into the hole
until it is quite full; there is no need to compress or plug the
sand. Cut the wick some centimetres from the orifice of the
hole, and then set fire to it. In about eight or ten minutes,

100 ANNUAL OF SCIENTIFIC DISCO VERr.

the match burns down to the powder and fh-es it. Then ensues
a violent shock, which immediately causes the detonation of the
nitroglycerine. The explosion is so sudden that the sand is not
even projected.

The wliole mass of the rock rises, is displaced, then re-settles
without any projection ; only a dull detonation is heard.

Only on examining the sjjot can an idea bo formed of the power
of the force developed by the exj)lo.siun. Formidable masses of
rock are slightly disijlaced and rent in every direction, and ready
to be removed mechanically.

The chief advantage is that the stone is onl}' slightly crushed,
and there is very liltle waste.

In the manner we have shown, from forty to eighty cubic
metres of rock may be detached by charges of nitroglycerine.

We trust to have shown by this notice the possil)ility of recon-
ciling the employment of nitroglycerine with every desirable
guarantee for public safety. — M. Koi'i', Comptes Rendus.

The following are extracts from a letter by T. P. Shaffner, in
the "Scientific American," for Nov., 18G6 : —

"When I visited the Iloosac Tunnel in August, I had not wit-
nessed the explosion of nitroglyewine in rock of the hardness of
the Hoosac Mountain. The tunnel is jjenetrating through solid
massed mica and quartz. The strata lie against the progress,
and there are but few seams and slips. It tears roughly, and in
no instance (piarries. Every culjic inch nuist be blasted.

" The ' heading' is G feet high and 15 feet wide. Below is the
' bench,' or bottom enlargement, 4i feet deep, the width of the
heading. In the west shaft it was about 300 feet in the rear of
the heading. The further enlargements are to be above and at
the sides. My experiments wei-e in the west shaft, ' bench ' and
* heading,' proceeding eastward.

" Prior to my arrival, good minei-s had been making from 2 to
3 feet per day with tlie ' bench.' The holes had been set from 15
to 20 inches back, drilling 4 holes to make the width of the
tunnel. These 4 holes were drilled 4 feet deep, charged with
powder and well tamped. After blasting the 4 holes, about 5
short holes, averaging 15 inches, had to be drilled in order to
make an even bottom. According to these figures, the number
of inclies to be drilled to make 60 7-10 feet lineal, would be 9,612,
Two men can drill about 100 inches per day of 8 hours, and
wages are §2.25 per day. The expense for miners, tools, and
incidentals, amounts to about $6 per 8 hours, for each 100 inches,
making a total of $566.72 for drilling. The time required to make
60 7-10 feet would be at least 20 days. There would be about 144
long holes, 180 short holes, and at least 36 blasts. This is the
I'ate of j3rogres3 that had 1>eeu made with gunpowder.

"My lirst experiment was in the 'bench,' as above described,
and within 3 days I advanced 60 7-10 feet. I used nitroglycerine,
exploded by the aid of electricity. If the rock could be removed
after each blast, I can make 70 feet in that time. I had 9 blasts
and 28 holes, 5 feet deep ; total inches drilled, 1,G80. The cost
of the nitroglycerine Avas less than the j)rice of gunpowder for the
same number of feet.

MECHANICS AND USEFUL ARTS. 101

"My next experiment was in the 'heading,' for a period of
3 days. The average speed per month with powder had been
64 feet, blasting every 2 hours holes 20 to 30 inches deep. When
I commenced my experiment, the rock was excessively hard, and
the trial was very severe against me. I blasted 15 holes every 8
hours ; holes 30 to 36 inches deep. Within the 3 days I made
14^ feet. The next 3 days the rock happened to be better for
blasting, and powder was used, making 6 4-10 feet. Number of
nitroglycerine holes 132, and about 4,356 inches for the 14^ feet.
Number of powder holes 180, and about 4,500 inches drillino-
making 6 4-10 feet. '^

" In the same class of rock, I am of opinion that 'I can make at
least 35 feet per week in the heading, and in a month of 27 daj^s
about 158 feet; making 94 feet per month more than can be ac-
complished with gunpowder.

" From these figures, the Hoosac Tunnel can be finished in less
than half the time and for less than half the expense by using ni-
troglycerine. From 8 to 10 years has been the estimated time for
completing the work, and the expense several millions of dollars.
From these economic considerations, the very able chief engineer
of that great enterprise is encouraged to belief in the early com-
pletion of the work by his adopting nitroglycerine."

Though this substance possesses very important advantages
over gunpowder, as a blasting and destructive agent, the attempts
to introduce it as a substitute have been attended by most disas-
trous results, ascribable, in part, to some of its pi'operties, and
too evident instability of the commercial product, but principally
to the thoughtlessness of those interested in its application, who
apjjear to have been induced, either by undue confidence in its
permanence and comparative safety, or from less excusable mo-
tives, to leave the masters of shijjs, or others who had to deal
with the transport of the material, in ignorance of its dangerous
character.

The precise cause of the fearful explosions of nitroglycerine
at Aspinwall and San Francisco will probaiily never be ascer-
tained ; but they are likely to have been due, at any rate, indi-
rectly, to the spontaneous decomposition of the substance, induced
or accelerated by the elevated temperature of the atmosphere in
those parts of the ship where it was stored. Instances are on
record in which the violent rujiture of closed vessels containing
commercial nitroglj'cerine has been occasioned by the accumula-
tion of gases generated by its gradual decomposition ; and it is
not improbable that a similar result, fiivored by the warmth of
the atmosphere, and eventually determined by some accidental
agitation of the contents of the package, was the cause of those
lamentable accidents. The great difficulties attending the purifi-:
cation of nitroglycerine upon a practical scale, and the uncer-
tainty, as regards stal^ility, of the material, even when purified
(leaving out of consideration its very poisonous character, and
its extreme sensitiveness to explosion by percussion, when in the
sofid form), appear to present insurmountable obstacles to its safe
9*

102 ANNUAL OF SCIENTIFIC DISCOVERT.

application as a substitute for gunpowder. — Journal of Frank-
lin Institute, Oct., 1806.

GUN-COTTON.

M. Blondeau makes the following communication to the
Academy of Sciences, Paris. If gun-cotton of good quality be
exposed for aljout four hours to the action of the vapor of ammo-
nia, it will soon assume a yellow tint, indicating its combination
■with the ammonia; and, after being dried, it furnishes a powder
which is unalteralde at ordinary temperatures, and even unde-
eomposable at 212° (Fahr.), and possesses au explosive force
greater than that of ordinary gun-cotton.

Gun-cotton has not hitherto been received with much f;ivor by
artillerists, but some recent experiments of Mr. Whitworth go
far to prove that, under certain circuanstances, it may be used with
advantage. He linds that a ciiarge made up of gunpowder and
gun-cotton, the former material being exploded lirst, gives a
lower trajectory, and will also admit of a lighter gun being used.
By this means, the great explosive j^ower of gun-cotton is com-
bined with the advanUiges due to the gradual action of ortlinary
powder.

GUN-PAPER.

Mr. G. S. jSIelland, of Lime street, London, who has distin-
guished himself among British makers of lire-arms, has i-ecently
invented a " gun-paper," to supersede the old gunpowder. The
invention consists in impregnating jjaper with a composition
formed of chlorate of potasii, 9 jjarts ; nitrate of potash, 4^ ;
prussiate of potash, 3i ; powdered charcoal, 3^ ; starch, l-12th
part; chromate of potash, 1-lGth part; and water 79 parts.
These are mixed, and boiled during one hour. The solution is
then ready for use, and the paper passed in sheets through the
solution. The saturated paper is now ready for manufacturing
into the form of a cartridge, and is rolled into compact lengths
of any required diameter. These rolls may also be made of re-
quired lengths, and cut up afterward to suit the charge. After
rollmg, the gun-paper is dried at 212° Fahr., and has the appear-
ance of a compact grayish mass. Experiments have been made
with it, and it has been reported favorably of as a perfect suljstitute
for gunpowder, superseding gun-cotton and all other explosives.
It is said to be safe, alike in manufacture and in use. The paper is
dried at a very low temperature. It may be freely handled with-
out fear of explosion, which is not produced even by percussion.
It is, in fact, only exploded by contact with fire, or at equivalent
temperatures. In its action it is quick and powerful, having, in
this respect, a decided advantage over gunpowder. Its use is
unaccompanied by the greasy residuum always observable in gun-
barrels that have been fired with gunpowder. Its explosion
produces less smoke than from gunpowder ; it is said to give less
recoil, and it is less liable to deterioration from dampness. It is
readily protected from all chance of damp by a solution of xyloidin
in nitric acid.

MECHANICS AND USEFUL ARTS. 103

In experimenting with this new explosive substance, six rounds
were first fired with cartridges containing 15 grains of gunpow-
der, and a conical bullet, at 15 yards range, which gave an average
penetration of 1 1-16 into deal. Six rounds were then fired with
10 grains of gun-paper and a conical bullet, at the same range,
and gave an average penetration of 1 3-8 into deal. Here was
33 per cent, less of paper than powder, and greater penetration
with paper. Six rounds followed with an increased charge of 15
grains of gun-paper and a conical bullet, at the same range, and
at each shot the bullet passed through a 3-inch deal. At 19 yards
range, 12 grains of the paper, fired from a pistol of 54 gauge
(ll-inch), sent a heavier bullet through a 3-inch deal. A fouled
revolver was jiresei'ved four days, but betrayed no symptoms of
corrosion after using gun-paper. It is expected that gun-paper
will be manulactured cheaper than gunpowder. — London Artisan.

NEW GUNPOWDERS.

Some interesting experiments were made in Paris recently
with a new kind of gunpowder, the invention of M. Neumann.
This composition appears to be very similar to that of ordinary
powder, but it has the property of not exploding unless subjected
to pressure. When laid upon the ground and ignited, the new
gunpowder burns slowly and leaves a thick crust. In the course of
the experiment, three barrels, each containing about thi-ee and a half
kilos, of powder.were placed in a temjiorary hut,and the powder was
ignited by means of a fusee. Large volumes of smoke were seen
to issue from the crevices, but no explosion took place, the powder
being simply burned. When tried in a rifle, the strength, when
the ramrod was well used, was found to be equal to that of ordi-
nary gunpowder ; but, when not rammed, it failed even to drive
the ball out of the muzzle. The composition of the powder re-
mains a secret for the present.

At a recent meeting of the British Association, a paper was
read upon the introduction of a new gunpowder for heavy ord-
nance, in which uiti'ate of barytes is substituted for saltpetre in
composition ; the consequence being that the powder, when ig-
nited, consumes more slowly, and the gases are developed less
rapidly, while the same eftect is produced upon the projectile as
regards its ultimate velocity.

NEW GUNPOWDER.

A new and very powerful gunpowder has been patented by
Captain Schultze, of the Prussian Artillery, which possesses some
very valuable advantages. In composition and mode of manufac-
ture it bears more resemblance to gun-cotton that to ordinary gun-
powder ; but its form is that of gunpowder, and it has none of the
sjiecially dangerous properties which have hitherto i^revented gun-
cotton from coming extensively into practical use. Cotton fibre
consists of "cellulose," a compound of six atoms of carbon, five
of oxygen, and ten of hydrogen ; while gunpowder is, chemically

104 ANNUAL OF SCIENTIFIC DISCOVERY.

spoakinof, "tri-nitro-cellulose," or cellulose which has had three
atoms of its hyrlroofen rc^placed by hyi)oiiitric acid. All kinds of
wood consist chiefly of cellulose ; the cellulose of wood, however, is
unlike that of cotton fibre, which is quite pure, being always com-
bined with more or less coloring matter, resin, and various eartliy
and other substances. It is obvious, therefore, that if we could
remove from wood all the substances otlier than cellulose which
enter into its comiJosition, and were to subject the pure cellulose
then remaining to the same chemical treatment that cotton fibre
has to imdergo in order to l)e converted into gun-cotton, we should
obtain a sulistance of absolutely the same composition as gun-
cotton, and diftering from it onh- in form. This is just what Capt.
Schultze does, with the result that he gets " tri-nitro-cellulose,"
not in delicate filaments like gun-cotton, exploding almost instan-
taneously, but in hai'd, compact grains, of any desired size, and at
least as slow of combustion as the densest gunpowder of the same
size of grain. While gun-cotton, being, at least for gunnery pur-
poses, only three times as powerful as its weight of gunpowder,
costs, weight for weight, six times as much as gunpowder costs, and
can only lie used safelj- by means of special methods, this new pro-
duct, wliile nearly foiu* times as powerful as gunpowder, costs,
weight for weight, considerably less than gunpowder, and can be
used in preciselj' the same way, the onl}' precaution necessary being
to use of the new powder only one-fourth as much as of the old.

Any hard wood is cut into sheets about one-sixteenth of an inch
thick, and punched into little cylinders, which constitute eventually
the grains of the powder, which is thus granulated at the begin-
ninginstead of attheend of the process of manufacture. To remove
all constituents except cellulose, these gi-anular cylinders are boiled
for about eight hours in strong solutions of carbonate of soda,
frequently changed ; after twenty-four hours washing in running
water, they are next steeped for two or three hours in a chlori-
nated solution ; after a second twenty-four hours' Avashing in cold
running water, they are submitted for six hours to the action of a
mixture of forty parts, by weight, of concentrated nitric acid with a
hundred parts, by weight, of concentrated sul^jhuricacid, one part
of the grains, by weight, being placed with seventeen parts by
weight of the mixed acids in an iron vessel, which should be kept
cool. The grains then being carefully drained, they are exposed
to cool running water for two or three days, then boiled in a weak
solution of carbonate of soda, again exposed for twenty-four hours
to running water, and carefully di'ied. Up to this point the gi'ains
are not explosive. The dried grains are now steejoed for ten
minutes in a solution of some salt or salts containing oxygen and
nitrogen — the best appears to be for every hundred j^arts by weight
of the grains, two hundi'ed and twenty parts of water, having dis-
solved in it twenty-seven and one-half parts of nitrate of potash
and seven and one-half parts of nitrate of barytes, at a tempera-
ture of 112° Fahr. After draining, they are dried in a chamber
at 90° to 112° Fahr. for about eighteen hours.

This new powder will be of use not only for small arms and
artillery, but for mining and engineering pm-poses; its great

MECHANICS AND USEFUL ARTS. 105

advantage in the latter is that its explosion produces no smoke,
therebj^ avoiding the loss of time incurred by the workmen under
ground in waiting for the smoke of common gunpowder to clear
av/ay ; it has all the advantages of gun-cotton, without its danger
and other disadvantages. — London Mechanics'' Mag., March, 1865.

THE PRUSSIAN NEEDLE-GUN. »

The deciding argument of the recent European battles has been
the Zund Nadel-Oewehr, — the Prussian needle-rifle. The wonders
which the Austrian ai'my have usually performed with the bay-
onet were completely estopped by this terrible weapon, as, load-
ing and firing it from five to seven times a minute, the Prussian
soldiery spent such a shower of bullets upon the advancing foe,
that, by the time they reached them, there were not enough left
living to do much harm. No men, however brave and deter-
mined, could stand the fire of these rifles ; and nothing so dis-
heartens an army as the absolute knowledge that it is fighting
against a terrible superiority in arms.

The " needle-rifle," which has been in use in the Prussian army
since 1848, but which has never till now been fairly tested, has
proved to be a most formidable and dangerous weapon ; and as the
Prussians have succeeded in this war, they may in great pai't con-
sider it due to their superiority in the possession of this fearful
instrument of warfare. It is a breech-loading rifle, the caitridge
used being made of stifi" card-board, the ball, powder, and explo-
sive composition being contained in one and the same cylinder.
Its great jjeculiarity is, that the detonating powder is placed im-
mediately in rear of the base of the ball, and between it and the
powder. The advantage of this is, that when the powder is
ignited, that portion next the ball, in which combustion is first per-
fected, exerts its full force upon the projectile, the powder in rear
also exerting its influence, as it becomes almost simultaneously
ignited. Under the present s^^stem, in which that part of the
powder next to the breech of the gun is first ignited, a portion of
the powder is frequently expelled from the gun with the ball, in a
condition of only partial combustion, the exjilosive force of the
powder first consumed being adequate to expel the ball and the
powder in its front, before the whole charge has time to become
entirely ignited. Thus, in the needle-gun, all the powder is con-
sumed and applied totUe best efi'ect, and so as to obtain its fullest
force at the same instant and in the same direction.

The needle-gun is a breech-loader, and, when the trigger is
pulled, a stout needle or wire is thrust through the base of the
cartridge, parallel with its axis, into the detonating charge by the
ball, causing its explosion and the ignition of the cartridge. In
accuracy the needle-gun cannot be surpassed ; and its eflective
range is said to be about fifteen hundred yards. Soldiers can
load and fire five times a minute ; and, in the recent fighting, they
have been in the habit, when either charging themselves or re-
ceiving charges, to keep the gun at the hip, and simply continue
putting in ca'i-tridges and discharging them, literally keeping up

106 ANNUAL OF SCIENTIFIC DISCOVERY.

Avli.'it my informant describes as a " rain of biiUols." This mode of
firinji: lU'Counts for the fact of so many of the Austrians bein<f
wounded in tiio le<^s and feet. — Druijgists' Circular, 18()G.

So mueii has been said al)out the Trussian needle-<i:nn of late,
in tiie foreign journals, and the success of the Prussians with it,
that many supjjose it to l)e a new invention. On tlie contrary, it
is t\ynty years old. Vie do not desire to depreciate it on this
gnnmd, but. Judging it solely I)y its intrinsic merit, it is not up to
the standard of American breech-loaders. All military men know
that an essential point in a Hre-arm is simplicity and certainty in
fire. Neither of these <iualilies is found in the needle-gun, for the
mechanism is clumsy, compared witli recent inventions, and the
ammunition is complicated, and costly to prepare. The principal
idea in this weapon is in tiring the charge from the front instead
of behind, as in other \veaj)ons. To do this, the percussion pow-
der is put into a cavity in tiic base of a paper sabot, between the
ball and the powder, the charge being exploded by a wii'e or
needle thrust through the cartridge.

The experience gained in the war of the rebellion shows us
that the " magazine arm," or that weapon where the charges are
contained in the breech, is most deadly, when in the hands of
skilful troops. Other breech-loaders have their good qualities,
but all who remember the part the Spencer rifle bore in the con-
test will concede the point we make.

Breecii-loaders have this disadvantage : troops must be trained
long and thoroughly, or in the heat of battle the charges will be
thrown awaj* from heedless firing. The Prussian army have had
experience with breech-loading guns for fifteen years, and in
their recent battles did well. — Scieiitijic Amencan, 18GG.

IMPROVEMENTS IN CANNON.

At the anniversary meeting of the American Academy of Arts
and Sciences, Boston, Mass., in May, 18G;3, the Rumford medal
was awai'ded to Prof. Daniel Tread well, of Cambridge, Mass.,
*' for improvements in the management of heat made and put in
practice bv him in constructing cannon of a series of coiled rings,
in the year 1842."

The following are extracts from the address of Prof. Asa Gray,
the President, on the occasion of its presentation, in Nov., I8G0 : —

"We in our da}-, within the last fifteen jears, have witnessed a
change in the means of attack and defence greater than any made
in the two hundred years previous, — a change involving a com-
plete revolution in tactics, both on land and on sea. To take a
single illustration from heavy ordnance, in which the importance
of the change impresses us, when we are told that our strongest
forts, ai-med with the best guns we had ten years ago, could op-
pose no eflectual resistance to the entrance of such ships as are
now built, into any of our harbors ; and that a shij) could now be
built and armed, which, siugl}', would overmatch our whole navy
as it was in 1855.

"Fortunately, the balance is redressed by equal improvement
in defence.

MECHANICS AND USEFUL ARTS. 107

"The improvement in fire-avms, both great and small, is in
their increased range and precision, Wlien the efiective range of
a mnsket-ball was extended from two hundred yards to fourteen
hundred or more, it became imperatively necessary that ordnance
should be improved in the same ratio, or it would be useless, as
gunners and horses would be picked off by small arms long Iiefore
they could effectively reach the enemy. This improvement in
guns of great calibre has been made, with consequences the
imjjortance of which, present and prospective, cannot be over-esti-
mated.

" But the point which we have to consider is, that this increased
range and precision are entirely dependent on the augmented
strength of the gun. The weakness of the gun is the only thing
that imj^oses a limit to the range short of the absolute strength of
the explosive material used. It is the strength of the gun which
not only gives the range, but makes rifling possible, with preci-
sion and all the advantages of the elongated shot. All inventions re-
lating to the different modes of rifling, the form of the projectile,
and the devices for breech-loading, are necessarily subordinate to
the question of strength : with this sufficient, those become simj^le
problems, to be rapidly determined by the ingenuity of many
inventors.

" Now the limit of strength of cast-iron and of bronze cannon
had long ago been reached. Excepting Captain Rodman's im-
provement, and certain modern advantages in working and cast-
ing metals, no material advantages had been gained over guns
cast in the reign of Queen Elizabeth.

" But the most effective guns of the present day embody new
principles of strength. They ai-e all built-up guns. With them
are associated the names of Armstrong, Blakely,.Whitworth,Par-
rott, and others. Whatever may be the relative merits of these
several varieties, our interest is confined to the question of their
strength, that is, to the principles of construction which have made
them stronger than common guns, and rendered their respective
subordinate imi^rovements possible.

"These principles are two, and their introduction at different
times into the manufacture of cannon constitute two successive
steps, and the only steps, which give distinctive character to the
guns under consideration. Both originated with Mr. Treadwell.

"These two inventions are often confounded, although moi-e
than ten years elapsed between them. The confusion is doubtless
owing in some degree to the fact that the two are found combined
in nearly all the modern built-up guns. The first initiated a sys-
tem of construction which may be designated as the coil system ;
the second, what may be named the hoop system.

" The first was successfully applied to the making of cannon by
Mr. Treadwell in the year 1842, and a full account of it was pub-
lished in 1845 : the gist of the invention being' in so constructing
the gun that the fibres of the material shall be directed around the
axis of the calibre.

"This method of construction is descriljed in Professor Tread-
weirs own language as follows : ' Between the years 1841 and

108 A?nSTJAL OF SCIENTIFIC DISCOVERY.

1845 I made upwards of twenty cannon of this material (wrong'ht-
iroti). Th(\v wore all made up oF rings, or short hollow eylln-
ders, welded together enihvise ; each ring was made of bars
wound upon an arbor spirally, like winding a ribbon upon a blocic,
and, being welded and shaj)ed in dies, were joined endwise when
in the furnace at a welding heat, and afterwards pressed together
in a mould l)y a hvtirost:itie press of one thousand tons' force.

*' 'Finding in tiie early stage of tlie manufacture that the soft-
ness of the wrought-iron was a serious defect, I formed those
made afterwards with a lining of steel, the wrought-iron l)ars
being winnid upon a previously formed st<'el ring. Eight of these
guns were six-i)ounders, of the conmion United St;ites bronze
pattern, and eleven were thirty-two-poundors, of about eighty
inches' length of bore, and one thousand nine hundred pounds'
weight.'

" The soundness and value of this principle of construction were
fully conru'mcd in England by the ex[)eriments of Sir William
Armstrong in l.'^oo, and attested by his evidence before a com-
mittee of the House of Commons in 18G:5. lie there describes liis
own gun as one ' with a steel tube surrounded with coiled cyl-
inders,' — as 'peculiar in being mainly comjiosed of tubes, or
pipes, or cylinders, formed by coiling spirally long l)ars of iron into
tubes aiiil weliling them on the edges, as is done; in gnn-barnds.'
His indirect testimony to the originality of Mr. Tread well's ]n-ocess
is equally clear, being that, within his knowledge, no cann(m had
ever been made ui)on this principle until he made his own in
18.')'), he lieing, as we must suppose, ignorant of what Mr. Tread-
well had done thirteen years before. The statement of Mr. An-
derson (witness before the Commons' Select CommittcM;), made
before the Institute of Civil Engineers in 1860, is equally explicit
as to the nature and value of this method of constructing cannon.
And, linally, the high estimate of its importance abroad is shown
not only In' the honors and emoluments conferred by the British
government on the re-inventor, but still more by the actual ailop-
tion of this gun as the most efficient arm yet produced. For it
must be borne in mind that the faults or failures, complete or par-
tial, of the Armstrong and similar guns, are not of the cannon
itself, as originally constructed, but of breech-loading contriv-
ances, of the lead coating of the projectile, or of other subsidiary
matters.

" That our colleague's invention, the value of which is now so
clearly established, should have been so generally unacknowl-
edged by inventors abroad is his misfortune, not his fault. For,
not only were his guns made and tested here, and their strength
as clearly demonstrated before 1845 as they have been since, not
only was a full account of the process and of the results published
here in that year, but a French translation of his pamphlet was
jjublished in Paris, in 1848, l)y a professor in the school of artil-
lery at Vincennes; and Mr. Treadwell's patent, with full specifi-
cations, was iniblished in England before Sir William Armstrong
began his experiments.

" The difficulties to be overcome in making such a gun, — great

MECHANICS AND USEFUL AKTS. 109

at all times, as Sir William Ai-mstrong and Mr. Anderson testify,
— were far greater in 1842 than in 18(33. These difficulties were
mainly, if not wholly, in welding large masses of wrought-iron in
the shape of tubes or cylinders. It is for overcoming these diill-
culties that this medal is bestowed, and especially for the means
and appliances by which this difficult mechanical achievement was
effected in the furnace ' by the agency of fire.'

" An incidental but noteworthy part of the improvement was the
welding by hydrostatic pressure, — an oijeration which is just now
coming into use in England, but has not yet attracted attention in
this country.

" We come now to the second improvement in the construction
of artillery, the invention of the hooped gun.

"This is not always clearly distinguished, even by those occupied
with the subject, from the gun formed of coiled rings. But a
simple statement will bring into view distinctly the new principle
of strength here introduced.

' ' If an elastic hollow cylinder be subjected to internal fluid press-
ure, the successive cylindrical layers of the material composing
it, counting from within outwards, will be unequally distended,
and the resisting efficiency of the outer layer will be less than
that of any layer nearer the axis. And if the walls of the cylin-
der are thick, and the internal pressure surpasses the tensile
strength of the material, its inner layer will break before the outer
one has been notably strained. Hence the tensile strength of a
square inch-bar of the material is the measure of the maximum
pressure the cylinder can bear, when constructed as guns were
befoi-e the introduction of the improvement now under considera-
tion. The improvement does away with this limit, and enables
us to go indefinitely beyond it.

" This is accomplished by so constructing the gun that the inner
laj'ers are compressed by the outer ; Avherel^y the internal press-
ure is first resisted by the outer layers, which must be distended
enough to allow the internal compressed portion to attain its
normal conditon before this internal portion (which is the first to
break in the common gun) is subject to any strain at all. It will
be perceived, that, if this principle could be rigorously applied, a
cannon could be made so perfect, that, when sul^jected to a burst-
ing pressure, every fibre, from the internal to the external sur-
face, would be at tliat instant equally extended, each contributing
its full share of resistance to fracture. The whole resistance
would 1)6 proportional to the area of fracture.

" This was supposed to be the case in common cylinders before
the error was pointed out by Barlow, and also by Lamie and Cla-
peyron. Aud it was this erroneous supposition that led Count
Rumford to his exaggerated estimate of the force of gunpowdei-,
as tested by its power of bursting gun-barrels. If he had used
the theory which gave origin to the hooped gun, his results would
nearly have agreed with modern observations.

"The demonstration of the superiority of the hooped gun, with
detailed directions for its construction, is contained in a pa2)er
read before this Academy in February, 1856, and published at the
10

110 ANNUAL OF SCIENTIFIC DISCOVERT.

bei^inning of the sixth volume of oiu* 'Memoirs.' This was the
first i)iil)lish(Ml account of the invciilioii, wliich hud been ])atented
neaily a year Ijeibre, Captain Bhikely\s pamphlet, puljlished in
Enijland in 18u8, sets fortli the advantages of tins construction l^y
simihir arguments ; as also does an elal)orate paper read by Mr.
Longridge before the Institution of Civil Engineers in February,
18G0. lioth these gentlemen, however, were engaged in researches
upon this subject at an earlier date, but not so early, it would
ajjpear, as was Mr. Tread well.

" The validity of the principle, and the soundness of Mr. Tread-
well's views ujion the whole subject, as set forth in his memoir,
have beea amply confirmed by special experiments made in
England with the'Blakely and Wliitworth guns, and by experience
in tliis country, during the last four years, witJi the Farrott and the
Blakely guns.

" It must not be supposed that the earlier invention is superseded
by the later one. That is usi'd in forming the hoops of the Farrott
gnn, and in most of the British guns. And the best gun which
could now be made, as experience has shown, would be composed
of a barrel of cast-iron or steel, inclosed and compressed by a
cylinder of coil.

"We need not discuss the question of priority of inviention be-
tween i\lr. Treadwell and others, comi)etit(<ics for a share in the
honor of producing the modern cannon. Ilis independence of
each and all of them has never been called in question. Nor will
it ever seriously be thought that the previous fntile attempts at
constructing wrou<i:ht-iron and banded guns — Ibredoomed failures
both in theory and i)raetic(!, and destitue of all pretension to a
knowledge of the guiding principles now clearly seen to be essen-
tial to success — should detract in the slightest degree from the
great honor which our associate has, by a clear insight into the
conditions of the i)roblem and the resources of physical science,
so fairly and comi^letely won.

" Upon these two inventions has been set the seal of experience.
But there is anotiier memoir, read iiy Professor Treadwell before
this Academy in April, 18G4, and printed soon afterwards, which
promises to add a third important improvement in the construc-
tion of artiller}'.

" Ferceiving that the body of a hooped gun, if made of unmal-
leable cast-iron, compressed by a soft wrought-iron hoojj, must give
way, by the fracture of the cast-iron hoop, before the hoop can
approach the ultimate limit of its strength, and that this was, in
fact, a principal cause of the failure of so great a pait of the large
guns of Blakely and Farrott, Frofessor Treadwell, as the jirincipal
result of this third investigation, proceeds to show, that, to attain
with effect the end sought for hy hooping a cast-iron gun, it is
necessary to harden the wrought-iron hooj} by cold hammering
and severe stretching before placing it upon the gun-bod}'. He
computes that, by this simple means, a hooped gun may be made
more than twice as strong as those which have been constructed
by Klakely and Farrott, the materials being in both cases the
same.

MECHANICS AND USEFUL ARTS. Ill

"In this important discovery, as also in other matters discussed
in his hitest memoir, we are gratified to see, that, although now
carrying the weiglit of morethan three-score-and-ten years, our
veteran colleague still keeps the lead, which he gained at the
start, of his competitors in this race of improvement.

"So completely do these three improvements cover the ground,
that, if the works of all other inventors who claim a shai-e in the
great gun of the nineteentli century were lost, the gun could be
restored (rifling excepted) from Mr. Treadwell's papers alone."

CASTING OF A TWENTY-INCH CANNON.

»

Another twenty-inch gun was recently cast at the Fort Pitt Iron
Works, Pittsburg, Pa., being the third one of that size. This is
the first naval gun, however, and is intended for the " Puritan,"
consort of the "Dictator," both ocean monitors. The two pre-
viously cast were army guns. They ai"e Rodman guns, that is,
cast with a water-cooled coi-e.

The quantity of metal melted at once was enormous ; not less
than 140,000 j^ounds, and three fui-naces were in use to accom-
plisli it in time, the fires being started at 4.30 A. m. on the morn-
ing of joouring. The iron was in the following proportion :
101,000 Juniata, second fusion ; 39,000 Juniata pig, from the
Bloomfield furnace : tliis is stated to be the finest quality of metal,
for gun founding, in the countrj". The furnaces were tapped at
12.10, and the mould was filled in a short time.

The length of the rough casting is 236 inches. The maximum
diameter is 65^ inches, and the minimum 48 inches. When fin-
ished, the breech of the gun will measure 64 inches in diameter,
and the nozzle 35A inches. The length of the cylinder bore is
147 inches, depth of chamber 10 inches. The thickness of metal
outside the bore, at the breech, is 22 inches, and at the nozzle
7 9-10 inches. . Diameter of trunnion 18 inches. At 9.20, Sunday
morning, the water was turned oft", at which the temperature was
97°. The core l)arrel was hoisted, when it came out ijerfcctly
clean, there being every indication of perfect success in the cast-
ing. After the barrel was hoisted out, a very small sti'eara of
water was allowed to flow into the bore, when it immediately
became steam. Tliis was to he continued until 8 o'clock, when
a column of cold air would be forced in, and the cooling process
completed in this way. — Scientific America?!,.

THE PALLISER GUN.

Last August, four Palliser guns were tested with perfect success
at the proof butt in the Royal Arsenal at Woolwich, under the
superintendence of Lieutenant-Colonel Freetli, Assistant Superin-
tendent of the Royal Gun Factories. These guns were formerly
cast-iron 32-pounders and 24-pounders, and have been converted
into 64-pounders and 56-pounders, at Elswick. Twenty more of
these guns arrived the same day at Woolwich, and will at once
be sent to proof. A 64-pounder Palliser gun has also undergone

112 ANNUAL OF SCIENTIFIC DISCOVERY.

a most severe test of eiKlurance. This was a 32-pouncler, weigh-
ii)<^ only .58 cwt. Acconliiis; to the "Tunes," the test was as
lollows : Two rounds, with uhaigrs of 16 lbs. of powder and loO
lb. cylinders ; 10 rounds, with charges of 20 lbs. of powder and
100 lb. cylinders; and, llnally, 10 rounds, with 16 lbs. of powder
and 6-1 lb. shells. The shells were loaded with their fuse-holes
toward the jiowdcr, an<l, as (he fuses had been taken out, the
flash of till' discharge set lire to the pinvdcr in tlu; shells anil burst
them in the gun. It was generally expected that this test would
have burst tiie gun, or, at all events, that it would have Ijlown
oil the muzzle, or otherwise have rendered it unserviceable; but
l)eyond tlie one fact uf the bore 1)eing scratciied by tiie splinter of
the shells, no injury was jjerce])tible, and the gun was loaded with
the same facility and lired as before. It ai)peared from a subse-
quent examination tliat some of the shells had burst before they
had moved, and that others had burst close to tlu; muzzle of the
gun. A number of 61-lb. shot were then fired with 16-lb. charges,
but, instead of the shot being rammed home, they were only
jjushed down to certain i)ositions in the gun, so as to leave vacant
spaces of o inches, 10 inches, 15 inches, 20 inches, and 25 inches
between the powder and the shot. To the astonishment of
every one present, the guu had not sustained the slightest injury.
It was therefore clecided l)y the Ordnance Select Committee to
put the gun through a supplementary trial to ascertain its maxi-
mum or highest power of endurance, when it will have to tire
20-lb. to 25-lb. and 30-lb. charges, with cylinders of 150 11)S.
weight. INlajor Palliser has expressed great confidence in the
Strength of the gun, and states that he has no fear of the result
of any reasonable amount of proof, even beyond what is abso-
lutely necessary. The trial, it is admitted, has already borne out
the anticipations of the inventor and mamifacturers, and has fully
justified the recommendation of the (Jrdnance Select Committee,
and their introduction of these guns for the consideration of the
"War Deijartmcnt to use up the heavy stock of guns on hand. On
account of their weight, their service charges will be only 6 lbs.
or 8 lbs. of powder. Sufficient evidence, it is stated, has ali'eady
been obtained to prove that we have thus a most efficient and
reliable addition to our stock of rifled ordnance ; a fact which, in
the present difficulties with which the government is embarrassed
for want of serviceable guns, will l)e hailed with much satisfac-
tion, more es^jecially as the two new guns now pronounced suc-
cessful, — those of Major Palliser and Mr. Frazer, — will be
produced at a cost far below that of the present guns, in which
the country have long since ceased to have any confidence.
— Mechanics' Magazine.

CHILLED SHOT.

Mr. Fairbairn, in his treatise on iron ship-building, which
appeared so recently as the close of last year, records his opinion
that cast and wrought iron were not materials calculated to make
a serious impression upon armor-plates, and that nothing had been
found to answer the purpose better than hardened steel. The

MECHANICS AND USEFUL ARTS. 113

cast-iron pi'epared by Dr. Price, and the case-hardened shot pre-
pared by Major Palliser, Mr. Fairbairn considered, might answer
the purpose in some cases; but he questioned whether this mate-
rial, however well prepared, could be made to hold together, and
not break in pieces when the shot struck the plates. So he came
to the conclusion that steel shot and shell were the only projectiles
suited for attacking iron-plated vessels. Major Palliser, however,
has recently succeeded in demonstrating most thoroughly and
practically, that, by his method of chilling the shot when cast, he
detains a metal jDossessing a hardness equal to that of steel and a
toughness ajiproaching very closely to that of wrought-iron. He
has thus solved one of the most important questions of modern
gunnery, — that of penetrating armor with shells which do not
explode until they have passed through the plate and backing,
or, in other words, completely through a ship's side. Major
Palliser is by no means the first to accomplish this object : the
credit of that is due to Mr. Whitworth, who eifected his purpose
with comparatively small projectiles and low charges of powder.
Following the latter gentleman, others have done the same thing ;
but two serious drawbacks to success were always present. The
shells for the most part exploded backward on contact ; and being
made of steel, were very expensive, their cost for large ordnance
ranging from £7 to £20 each projectile. So, on the score of im-
perfection and of costliness, absolute success was not attained by
any, nor, until Major Palliser had perfected his chilled shot, which
are both cheap and eiiicient, was it considered attainable. But
the question was set at rest by a series of experiments which
were carried out last week, at Shoeburyness, with various kinds
of shell.

These experiments wei-e instituted for the pm-pose of testing
Major Palliser's chilled shells against those of the best steel pro-
jectiles, and in their results proved most valuable. The principle
upon which Major Palliser manufactures these shells is worthy
of notice, as being something more than the old process of chill-
ing. As the shells ai-e required for a particular purpose, they
must have something more than a mere chilled surface ; a definite
and carefull}' determined hardness must be imparted throughout
the metal. This condition is attained by a selection and combi-
nation of those brands of iron which have been found by experi-
ment to chill to the exact extent required, a careful mean being
observed between iron which it is diificult to chill and that which
chills too hard. Added to the principle of manufacture, is the
principle of construction, which goes far toward the success of
the projectile. The form given by Major Palliser is such as will
convert the sudden shock of impact as much as possible into a
uniformly increasing pressure. In other words, the projectile
has an elongated, pointed head, which is as essential an element
in it as is the perfect chilling of the metal. Upon the occasion in
question, the firing was ivom an ordinary seven-inch wrought-iron
muzzle-loader, with full battering charges of twenty-two pounds
of powder, and a range of two hundred yards. The shells were
directed against a "Warrior" target, which was built of the
10*

114 ANNUAL OF SCIENTIFIC DISCOVERY.

ordinary four-and-a-half-inch plate, with eitrhteen inches of teak
backinij, and an inner iron skin ; the whole well braced and
stren;2;thcned. Half tlie target was bolted on Mr. IJasconib's j^lan
of India-rubber pads, the other half of the bolts being secured
by j\Ir. Paget's steel cup washers. At the conclusion of the ex-
periments it was found that Mr. Bascomb's system had stood
better than ^Ir. Pagt't's ; but then it appears that the shots almost
invarial)ly struck that part of the target boltcsd on Mr. Paget's
principle, while that i)orlion fastened with Mr. Bascomb's washers
was scarcely touched. The experiments were commenced by
firing a steel shell on Major Alderson's plan, having a screwed
base, and being charged with three pounds of loose jjowder.
The shell penetrated the four-and-a-half-iueh plate, but did no
more, except to exjilode backwai-d from the face of the target.

The next shell, wiiieh was of the best steel, of Mr. Firth's, passed
through the plate anil entered the wood backing, but it exploded
outward as the first had done. The third shell struck on the edge
of the hole made by the first, passing easily through and explod-
intr in the teak backing, which it set on fire. Other shells were
tricil, with similar results, in some instances ; in others tliey were
even less satisfactory, some of Mr. Firth's shells bursting before
they reached the target: a few exploded in the gun. Three of
Sir William Armstrong's conical-headed shells, made on the Bel-
gian pattern, witli a sharp cone, were fired, and produced a simi-
lar efi'ect to those previously fired. After all the steel shells had
been tried. Major Palliser's chilled-iron sliells were tested, and the
first shot proveil the superiority of the system over all the others.
The shell struck an iminjured i^ortion of the target, and went
through the plate and backings so quickly as not to explode until
it had passed beyond. The backing whei-e the shell had passed
through was splintered into fragments ; and had th(! ol)ject been
the side of a ship, instead of a target, the results would have been
most damaging to a gun's crew at quarters. The charge of the
second Palliser shell did not explode; but, after passing through
the target, the projectile broke itself up into fragments, which were
sent spinning al)out in all directions with a velocity neai'ly as dan-
gerous as an explosion would have imparted to them.

The results of these two shots were so conclusive that the charge
of powder was reduced to eighteen pounds, with which the third
shell was fired. This shell missed the target, and went away to
sea; the next, however, which was fii'cd Avithout a bui-sting
charge, went through the target, breaking up and scattering its
fragments as before. The charge was then further reduced to
sixteen pounds of powder, which was nearly equal to increasing
the range from two hundred yards to one thousand yards, while
the velocity of each shot, on sti-iking, was less than thirteen hun-
dred feet per second. But for all this, the next shell penetrated
the plate and backing, and was only stopped by coming in con-
tact with one of the heavy struts which suiij^oi'ted the target from
behind, and which it broke. At this stage of proceedings, the Oi'd-
nance Select Committee ordered the firing to cease, considering
a continuation would only be a waste of time and powder. This

MECHANICS AND USEFUL ARTS. 115

•will be the more apparent when we state that, a few weeks since.
Major Palliser's projectiles were tried against the " Bellerophon"
target, Avhich has six inches of iron, with twenty-two inches of
teak, and an inch iron inner skin. The results, however, were
precisely similar to those with the "Warrior" target, the shells
passing through quite as easily. The results, therefore, constitute
a victory for guns over armor-ijlates, and this long-pending ques-
tion may be considered for the present as definitively settled. For
the present we say, because, although the " Warrior's " strong sides
afford but little more jirotection against Major Pailiser's shells than
would those of a wooden ship, it is possible that we may in time
find some means of neutralizing the damaging effects of these pro-
jectiles. It always has been so; throughout the history of the
question, victory has always alternated between the guns and the
plates. But, unquestionalily, Major Palliser has gained such a
victory as will not easily be reversed, and has inaugurated such
a condition of things as will require a long time and a considerable
amount of scientific and engineering skill to render obsolete. —
Mechanics' Magazine.

CHILLED SHOT AND THE SHOEBUEYNESS EXPERIMENTS.

As the facts come to hand, it is apparent that the success of the
shots made by the nine-inch gun at Shoeburyness, on the 20th of
September, was due mainly to the character of the projectile, and
not to the gun nor the charge of powder. The Palliser shot and
shell are made of chilled iron, which has been pretty satisfactorily
proved to be superior in penetrating qualities to either wrought-
iron, ordinary cast-iron, or steel. Both steel and chilled shots were
used in these experiments, but while the hardened-steel shots
failed to penetrate through the target, and either broke in pieces,
or were compressed and bulged out of shape, every one of the
chilled-iron shots did effective service, never in one instance
changing in form.

The target used was about forty feet long by eight feet high,
built of single thickness of rolled wrought-iron, eight inches
through, bolted by the Palliser screws to a backing of eighteen
inches of teak timber and an inner plate of three-quarters of an
inch iron. The whole was sustained by heavy timber backs. The
face of the target was not in one plane, but half of its length was
inclined at an angle of thirty degrees to the other half, the line of
fire being the same in both cases ; so that a shot against the in-
clined face would make, with the target, an angle of sixty degi-ees.
The gun was a nine-inch muzzle-loading rifle, Avith increasing
twist of thread, throwing shot of two hundred and fifty pounds
with charges of forty-three pounds of powder. The distance fired
was two hundred yards.

The steel shot were cylinders having either pointed heads struck
on a circle the diameter of the shot, flat heads, or the Belgian or
ogee head. All of them were hardened in prussiate of potash and
oil, or water. Some of them were solid, others shells with the
head screwed into the body, or the base secured in the same man-

116 ANNXTAL OP SCIENTIFIC DISCOVERY.

ner. Out of twenty-four shots, twelve were of this character. Not
one of them passed throuirli th(^ t:ir_2;et, and every one was either
broken into fragments or bul;i^ed out of shape.

The Palliser chilled shots in every case penetrated the ii'on plate,
and in one instance, on the square face of the target, went en-
tirely through plate, backing, and hning, and lodged in a pile of
iron plating, brick, and stone masonry, twelve feet in the rear of
the target. In no instance was the form of the shot changed. The
Palliser shots and shells have heads formed on a radius of one and
a half diamet(>rs of th(! cylindrieal jiortion. AVhenever the Palliser
shots struck the inclined face of the target they penetrated, while
the cast-steel shots sometimes glanced off.

One circumstance in this trial is remarkable. The steel shots
"wei-e so hot after striking the target that tliey could not be handled,
while the eliilled shots were barely warm. This, witli the fact of
the change of form in the steel projectiles, proves that much of the
energy of the shot had been expended in this direction, instead of
in iienetration.

While the velocity of the shots fired in our Fortress Monroe
experiments exceeded in no instance 1,155 feet per second, that
of those in this Shoeburyness trial ranged from 1,2G0 to i,340 feet
per second. At such an initial velocity, with a distance of only
two hundred yards l)etween the gun and target, it ceases to be
very surprising that it was possible to throw shot thi'ough such a
barrier. — Scientific American.

FENETRATIOX OF SHOT, AND RESISTANCE OF IRONCLAD

DEFENCES.

Captain Noble has lately caiTied out a series of experiments
under the direction of the Ordnance Select Committee, for the
purpose of determining various i)c)ints connected with the i*esist-
ance of iron plates, and his paper forms part of a report which
he has submitted to the committee.

The above series of experiments were instituted for the purpose
of determining the foliowing points : 1st, To determine the rela-
tive penetrating effects of two steel shots on an iron plate, pro-
vided they strike with the same "work" or mechanical effect,
notwithstanding the one may be heavy, with a low velocity, and
the other light, with a high velocity. 2d, To determine the rela-
tive resistances of a jjlate to penetration, by two steel shot of
similar form of head, and striking with " work " proportional to
their respective diameters. In order to determine the first point,
the committee fired a number of hemispherical-headed steel shot
from a muzzle-loading gun of 6.3-inch calibre, at 4^ and 5i-inch
unbacked plates, the weights of the shot being different, viz.,
35 lbs., 70 lbs., 106 l])s., and the diameters the same, viz., 6.22
inches. The charges with which these projectiles Avere fired
were arranged so that the " work" was the same in each case, —
that is to say, the velocity on impact of the light shot was much
gi'eater than that of the heavy shot, while the expression W v^,
weigiit of shot multii)lied by the square of its velocity, was con-

MECHANICS AND USEFUL ARTS. 117

stant. The results of these experiments were very interesting,
and are fully detailed in the tables which accompany Captain
Noble's report.

The conclusions which have been drawn from these results will
be given when the second point has been considered. To deter-
mine this question, viz., the relative resistance of a plate to
penetration by two shot of similar form of head, and striking with
" woi'k" proportional to their respective diameters, the commit-
tee fired a series of steel hemispherical-headed shot, of various
weights and diameters, at 4^ and 5^-inch unbacked wrought-iron
plates, the velocities being so arranged that each projectile should
strike with a work proportional to its diameter. Thus, suppose
the comparison to be made between a 7-inch shot animated with
a " work" represented by 1,000, and a 9-inch projectile, the latter
should strike with a " work " reijresented by 1,286, or in the pro-
portion of 9 to 7. Having finished the details of these exper-
iments. Captain Noble jsroceeded to consider the effects of shot
striking a plate obliquely or at an angle. A small number of
experiments have lately been made in connection with this part
of the subject, and, although further trials are necessary, the
general results go to prove that the power of perforation pos-
sessed by the shot is diminished in the proportion of the sine of
the angle of incidence to unity.

The subject of cast-iron jirojectiles next claimed attention, and
Captain Noble explained the difference between the effects of
cast-iron and steel shot. With the former, much of the total
"work" is expended in breaking uj^ the projectile on striking,
and hurling the pieces in different directions, whereas, when the
shot'are carefully manufactured of the very best steel, very little
"work" is done on the projectile, and, in some instances, the
material of the shot has been so perfect, that its altei-ation of form
after penetrating the plate has been almost inappreciable.

From this subject Captain Noble j^assed to the consideration of
the proper form and material of projectiles to be used for the
penetration of iron-clad defences. It has been clearly demon-
strated by numerous experiments, that ordinary cast-iron is
almost useless as a material for the manufacture of the above
projectiles. Steel is an excellent material for shot, but it is also
most expensive ; and, as recent experiments have shown that Pal-
liser's chilled iron is almost, if not quite, as good as steel, we
shall probably use this material for solid shot, and employ steel
for shells alone. Various forms of head have been proposed for
steel projectiles. Thus, we have had the flat head, relied on by
Mr. Whitworth, the round head, elliptical head, etc. The flat
head has gained a great reputation, from being the shape used by
Mr, Whitworth in his first experiments against the "Warrior" tar-
get. Of all these forms, however. Captain Noble prefers the
pointed, or ogival head; and he described, by means of a dia-
gram, the difference in effect between the pointed and the blunt
form. The blunt, that is, flat-headed or round-headed shot on
striking an iron-clad structui-e, such, for instance, as the "War-
rior," punches a piece of armor out of the plate, and drives it into

118 ANNUAL OF SCIENTIFIC DISCOVERT.

•

the backing; the shot, however, has no means of ridding itself of
this piece of plate, and, consequently, has to push it in front of it
through the backing. It is needless to remark that this piece of
jagged armor-plate must greatly increase the resistance which
the shot meets in passing througii tlie backing. When, however,
the shot is of the form of a pointed ogival, the results of its action
are far different; this projectile cuts, or rather tears, through tlie
armor-plato, and the pieces of Iiroken plate are bent back and
forced into the barking round tiie edge of the hole ; the shot then
passes througii witiiout carrying any jagged armor in front of it.
Captain Noble then proceeded to give a short detail of some late
experiments witli pointed shot and Alderson's solid-lieaded steel
slull, Avhich goes to prove that this foi-m is much superior to any
hitlierto tiitnl.

The subject of iron-clad ships was then entered on, and a brief
summary given of the experiments against targets representing
actual vessels. The conclusions wiiicli might be drawn from the
whole of tlie experiments were ; 1st, Where it is required to perfo-
rate the jilatc, tlie projectile should be of a hard material, such as
steel or chilled iron. 2d, The form of head best suited for the
perforation of iron plates, Avliether direct or oblique, is the ])()inted
ogivtil. 3d, The best form of steel shell is that in which tlie
powder can act in' a forward direction, and which is furnished
Avith a solid steel head, in the form of a pointed ogival. 4th,
When chilled iron can be made of the best quality, it is almost, if
not quite, as etfective as steel for solid shot, and, where the pro-
jectile can perforate with ease, the chilled shot is more formidable
than steel, as it enters the ship broken up, and would act as
grape. 5th, To attack Avell-Iiuilt iron-clads effectually, the guns
should be, if possible, not under 12 tons weight and 9-inches
calibre, fii-ing an elongated projectile of 250 lbs., with about 40
lbs. of powder. 6th, When the projectiles are of a hard material,
such as steel, the perforation is directly projiortional to the "work"
in the shot, and inversely jiroportional to the diameter of the
projectile; and it is immaterial Avhetlier this " work" be made up
of velocity or weight, within the usual limits which occur in prac-
tice. 7th, The resistance of wrought-iron ^ilates to perforation by
steel projectiles varies as the square of their thickness. 8th.
A plate at an angle diminished the effect as regards power
of perforation in the pi'oportion of the sine of the angle of inci-
dence. 9th, The resistance of wrought-iron plates to perfora-
tion by steel shot is not much, if at all, increased by backing simjily
of wood ; it is, however, much increased by a rigid backing, either
of iron combined with wood, or of gi-anite, iron, bricks, etc,
10th, Iron-built shijis, in Avhich the backing is composed of com-
pact oak or teak, offer much more resistance than similarly clad
Avooden ships. 11th, The best form of backing seems to be that
in Aviiich Avood is combined with horizontal plates of iron, as in
the " Chalmers," " Bellerophon," and " Hercules " targets. 12th,
An inner iron skin is of the greatest possible advantage ; it not only
has the effect of rendering the back more compact, but it prevents
the passage of many splinters which would otherwise find their Avay

MECHANICS AND USEFUL ARTS. 119

into the ship ; therefore, no iron-clad, whether iron-built or
wooden-converted, should be without an inner skin. i;3th, The
bolts known as "Palliser's bolts" are the best for securing
armor plates. In these bolts the diameter of the shank is
reduced to that Avhich it is at the screwed end. The author of
the paper preferred the English punching system of higli charges
with small shot to the American racking system of heavy cast-iron
shot propelled with low charges, on the ground that by the former
method, a ship might be sunk, or some vital part injured, in much
less time than would be required to destroy her by the American
system. — Beport of British Association, 1866.

:natueal philosophy.

THE NEW THEORY OF LIGHT.

TiTE following are extracts from a letter to the " Reatler " by J.
G. Macvic-ar, on Professor C. Maxwell's elcctro-niagnetie theory
of light, of which he says : '♦ A slight inspection is suflicient to
show that it sets tlie seal of mathemctical consistency and prestige
upon ideas which must modify profoundly all our popular ideas
on solar radiation. With regard to light, it sanctions the idea
that it is an electro-magnetic phc^nomonon, and such, therefore,
that it must observe tlie laws and produce the 2>henomena of what
is commoidy known as polarized action. And does not tiiis view
at once relieve speculative astronomy of some of its gi'catest
difliculties, and open the way for a happy exidanation of some
of the most remarkable but still unexplained phenomena of the
heavens ?

"Thus, our first physicists, taking for gi\anted, as to the solar
action, the hypotliesis of an universal and indiscriminate radiation
in all directions into sj)ace (or in accordance with modern science,
let us say into the ether) by such a body as the sun, just as if he
were a sj^hcrical gong poised in compressed air, and struck from
within sinniltancously all round, have been bestowing of late
years infinite pains to ex2)lain how his brightness is kept up
during all time, without any loss, so far as can be discovered.
But, if not gross mechanical undulations to and fro in compi-essed
air, but a rhythmical action in ctlicr — electro-magnetism, in short
— is to be the type to Avhich light and radiant heat are to be re-
ferred, then there will be no waste of solar action at all, and there
need be no more concern about the permanence of the sun's bright-
ness. For if the solar action, with respect to which, so far as ob-
servation goes, we know only that it illuminates the vai'ious mem-
bers of our planetary sj^stem, be of an electric or electro-magnetic
nature, then, after having induced a similar state of action in
the medium immediately surrounding him, — that is, after having
surrounded the central orb Avith a photosphere, — it will render
the ether immediately beyond almost, and soon altogether, non-
conducting in all directions, excei^t those in which bodies in a
dissimilar state pi-esent themselves, — that is, the sun will be in-
sulated in the ether, except in the direction of planets, satellites,
meteorites, etc. In all other directions, his action will be con-
sei-ved. And even in the direction, in which he radiates to a
distance, he will receive back again as much as he gives away.
Such is the well-known phenomenon of electrical and magnetic
action. In exchansre for the lisrht and heat which the sun gives
to the planets, he will receive from them a negative, reciprocal

120

NATURAL PHILOSOPHY. 121

complemental or harmonic action, by which his own will be sus-
tained or increased or diminished, according as the amount of
dissimilarity existing between him and them is greater or less at
the time. The solar radiation proper to the same column of space
will be more intense in winter than in summer, and in the arctic
regions than in the torrid zone.

" Again, it is a serious undei'taking to explain on the hypothe-
sis of universal and indiscriminate radiation, diminishing as the
square of the distance increases, the brightness or even the visi-
bility to us of the distant planets. But what we observe in natui'e
is precisely what we should expect on the electro-magnetic theory
of light. The remote planets, by being placed in jjositions which
would tend to involve them in coldness and darkness, are thereby
rendered in these respects more dissimilar to the central orb ;
they will therefore be all the more illuminated and warmed by
him; and the climate of the most remote members of our system
may possibly be as genial, and their day as bright, as ours.

" Again, since all the bodies between which and the sun, ac-
cording to this theory, action and reaction take place, circulate
in planes corresponding to low latitudes in the sun, a reason
appears why these regions of the solar disk should be peculiarly
the regions of storms in his photosphere ; and the way is open
to a theory of sun-spots and faculfe in a direction in which indeed
a step has been made already by Mr. Balfour Stewart, in con-
necting certain states of the solar illumination with the positions
of the planet Venus."

VELOCITY OF LIGHT.

The observations of the eclipses of Jui^iter's fii-st satellite, and
those of the phenomena of aberration, lead directly, although
with a different degree of approximation, to the determination
of the time light occupies to run over the mean distance of the
sun from the earth. To deduce from this the absolute value of
the velocity of light referred to our ordinary units of length, we
must know how many miles are contained in the distance from
the sun to the earth. The value of this distance is found by
means of the parallax of the sun ; we designate thus the angle
under which, being at the sun's centre, we Avould see the radius
of the earth. The sun's parallax, calculated from the observa-
tions of the last transit of Venus over the disk of the sun, is fixed
at 8.57 seconds ; hence the distance of the sun from the earth is
equal to 24,109 times the radius of the earth, or to 95,384,900
miles. As this length is run over by the light in 8 minutes 18
seconds, or in 498 seconds, we conclude that the velocity of light
is 191,391 miles in a second.

However, for some years, several circumstances have conspired
to make us believe that the determination of 8.57 seconds given
as the value of the sun's parallax is too small, and that th.e pai-allax
ought to be augmented by a quantitj^ not less than the thirtieth
of its value, which would elevate it to about 8.9 seconds. From
11

122 ANNUAL OF SCIENTIFIC DISCOVERT.

this increase in parallax results a diminution in the earth's dis-
tance from the sun, and consequently in tlic distance fjone over in
8 minutes 18 seconds by the light; the velocity of light will
therefore be reduced to a' little less than 180,420 miles in a second.
The next tranf*it of Venus, wliich will hapj^en in 1874, cannot fail
to set at rest all doubts which may yet remain on this jjoint, —
Delaunay, in Scientific American.

MECHANICAL EQUIVALENT OF LIGHT.

Professor Thomsen of Copenhagen has ascertained that the
mechanical equivalent of light, of the luminous ratliation as
distinct from the obscure radiation, from tlie llanic of tlie French
standard bougie is as nearly as possible 1.74 kilogrammetres per
minute, being about 1-50 of the mechanical equivalent of tlie
total radiation from the same Hame. A writer in " Cosmos" has
calculated from this the mcciianical equivalent of the total light
of the sun. He finds it to amount to something like that of 1,2;J0
septillions of bougies, or to 35 billions of tons lifted a billion of
kilometres ])er second — the lifting of 35 billions of tons (French)
a billion of kilometres being about equal to lifting the weight of
the earth 20 feet.

COLOR OF SUNLIGHT.

M. Memorski, of Vienna, confirms M. Brucke's observations,
that diffused solar light, instead of being perfectly white, is tinged
with red, just as the flames of gas or lamjxs are tinged with yel-
low. Difl'used light, received at noon through a cloud}^ sky, de-
viates by one twentv'-second part of the chromatic circle from the
extreme red of the spectrum toward the violet. The light of burn-
ing magnesium, which appears to be so like sunlight, has also a
tinge of violet.

COLORS IN THEIR RELATION TO ARTIFICIAL LIGHT.

Never select colors in the evening, is an old maxim, whose value
can be attested by many a disappointed purchaser, who, ignorant
or disregarding tliis advice, and deeming himself the favored pos-
sessor of some tint of rare excellence, discovers, on the return of
daylight, a color far from equalling his anticipations. The artist,
overtaken by darkness, hastens to apply the last touches to some
masterpiece ; but the morning light reveals how jjoorly his in-
tentions have been realized. The cause of this inconstancy is
explained, and a remedy suggested, in a late article in the "Pho-
tographic News."

From the spectral analysis, we learn that the flames of our
lamps or gas-lights contain sodium, which, in burning, yields a
yellow flame, as strontium gives a red, and iridium a Ijlue flame.
Now, when the color blue is illuminated by the yellow ligiit, it ap-
pears green ; but if the flame strikes a color complementary to

NATtTRAL PHILOSOPHY. 123

yellow, it will appear white or black, according as the body has,
or has not, the power of reflection ; which is equivalent to saying
that this flame alters the nature of colors, deepening the hues of
some, and extinguishing others.

Take a spirit-lamp and put into it a piece of common salt ; the
wick will soon become saturated with sodium in solution; the
flame, in consequence, will be yellow, and all colors will assume
a monotonous white, black, or gray. It is only when this sub-
stance is in excess that we have the total extinction of colors, but
a flame less rich will produce a partial extinction, and this is the
reason why coloi's are at all visible by gas-light. It may be asked,
whencedoes illuminating gas derive this sodium? From the coal;
from the water with which the gas was washed ; it comes also
from matters employed in its purification, and probably even from
the atmosphere.

The only hues which resist only slightly the yellow flame, are
furnished by the blue ; all the other colors are profoundly modi-
fied. Fortunately, the flames which serve as sources of light are
never saturated with sodium, hence the effects are greatly mod-
ified.

The light from the burning of magnesium alone brings out the
various colors, both natural and aitificial, in the same hues as they
appear by daylight. The services of chemistry render, then, to
painting, not only colors more or less rich, but also it has endowed
it with a mode of lighting, whereby the painter may be able to
work at night without incurring mistakes or illusions. — Scientific
American.

SPECTRUM OF AQUEOUS VAPORS.

M. J. Jannsen has just communicated to the Academy of Sci-
ences a memoir " On the Spectrum of Aqueous Vapor." His
observations Avere made with an iron tube thirty-seven metres
long, filled with steam, under a pressure of seven atmospheres ;
the light was furnished by sixteen gas jets. The spectrum showed
five dark bands, of which two, well marked, answered to D and
A (Fraunhofer) , and reminded the observer of the solar spectrum
seen in the same instrument toward sunset. According to the
first comparisons made between the spectrum of steam and that
of solar light, it appeared that the group A, B (in great part, at
least), C, two groups between C and D, are due to the aqueous
vapor in the atmosphere. Another interesting result was given by
the spectrum. The spectrum was very dark at the violet end,
and brilliant in the red and yellow, showing that aqueous vapor is
very transparent to the latter rays, and suggesting that it will
appear orange-red by transmission, and redder, according to the
thickness of the layer. This result requires to be carefully veri-
fied, and, if established, will explain the redness always observed
at sunrise and sunset. He hopes soon to be able to pronounce
upon the existence or non-existence of aqueous vapor in the at-
mosphere of the planets and other stars : at present he can only
say, that it does not exist in the atmosphere of the sun.

124 ANNUAL OF SCIENTIFIC DISCOVERT.

COMFLEMENTARY COLORS.

The production, by M. Niepce St. Victor, of black in photogra-
phy, by means of couiplomL-ntary colors, has j^iven rise to re-
searches on the suljjcet by !M. Chevreul, -wlio found that, although
complementary radiations of the spectrum produce white, those
radiations which emanate from complementary coloring matters,
ajiplied in succession or simultaneously to Ihe cloth, etc., afford,
according to the accuracy of the proportions, black, l)rown, or
gray. Thus, a blue pattern printed on orange will ajjpear black.
This subject, when fully developed, may have a most important
beai'ing on arts and manufactures.

NEW rOLARIZIXG FRISM.

!M^r. Ilartnack and Prazmowski recommend deviating from
the form of tiie Xichol prisms. The shape they recommend is
shoi'ter, ami has both ends normal to the incident and emergent
rays. According to the cementing substance employed, they give
the following angles : With Canada balsam, refracting index
1549, the faces of the Iceland si)ar make with the i)lane of sec-
tion an angle of 79°; with balsam of copaiba, index refr. 1.507,
the angle is 76°. 5 ; with linseed oil, index refr. 1485, the angle is
73°.5; rich poppy oil, index refr. 1403, 71°. 1. The two middle
ones give the largest angle of the field, viz., 35°.

WHY THE SKY IS BLUE.

It is generally supposed that the Idue color of the sky is due to
moisture in our atmosjihere ; and the idisa seems to be confirmed
by the intensity of the color during the moist weather of summer,
when compared with the sky of the more dry-weathered winter.
It has recently been shown by Prof. Cooke, of Cambridge, in a
paper read to the Amei'ican Academy of Arts and Sciences, that
this view is coiTCct. He has found, by means of the spectroscope,
— a very delicate instrument of analysis, by which the; most minute
substances, even when at a distance, can be detected, — that the
aqueous vapor of the atmosphere al^sorbs most powerfully the yel-
low and red rays emanating from the sun, leaving the blue rays to
be ti'ansmitted, and thus accounting for the color of the sky. The
instrument also proves that the color is due to simple absorption
of these rays by the water, and not to repeated reflections from
the surface of an infinitj^ of drops, as has been supposed.

DEFECT IN THE POLARISCOPE, WITH A SIMPLE AND EFFECT-
IVE REMEDY.

The author stated, that, having been engaged in some exjieri-
ments with polarized light, projected on a screen by means of the
oxy-hydrogen lantern, he discovered that even the best instru-
ments which were consti-ucted were inefiicient, inasmuch as none
but the axial rays transmitted through the condensers were polar-
ized, the main body of the luminous cone undergoing reflection

NATURAL PHILOSOPHY. 125

from the polarizer without being really polarized. He remedied
this by intercepting the liglit with a flint concave lens before it
reached the polarizer, so that the whole mass of rays, being pi-o-
jected in a parallel direction, was completely polai-ized. On leav-
ing the polarizer, the rays were again converged, before passing
through tlie crystal, or other object to be exhibited, by a small
achromatic lens, which thus acted as an achromatic condenser.
It was stated that this arrangement effected a most imi^ortant
increase in the brilliancy of the object exhibited on the screen. —
J. Traill Taylor, in Reader.

COMPARATIVE INTENSITY OF THE LIGHT OF THE MOON
AND OF VENUS.

On June 20, 1865, at 3 A. M., the moon and Venus were in
conjunction, in the latitude of Lyons, France, so that both bodies
could be seen in the same field of vision. This afforded an oppor-
tunity of comparing the light received from them. The surfaces
taken for comparison were those affording rays at the same angle
of incidence ; and, on the moon, the region was that between the
craters Rocca and Eirchstadt, over the very brilliant surface to the
southeast of Grimaldi. It was found that the light from this
brightest part of the moon was only one-tenth of that reflected by
the surface of Venus. — Chacornac, in Comptes Beiidus, 58.

TRANSPARENCY OF THE SEA.

Father Secchi has come to the following results, from experi-
ments made near Civita Vecchia, at from six to twelve miles from
the coast, the sea being clear and calm. It was found that the
maximum depth at which a white disk, ten feet in diameter, was
visible from the surface, when the sun was sixty degrees above
the horizon and the sky clear, was about one hundred and forty
feet. In descending, white disks appeared first of a light green
color, next of a clear blue, then the blue became gradually' darker,
until, at the depth mentioned, they could not be distinguished.
Yellow or sand-colored disks, ceased to be visible much sooner
than white disks, becoming invisible at depths varying from fifty-
five to eighty feet, according to their tint.

CURIOUS EXPERIMENT.

The following good lecture experiment has been suggested by
M. J. Niekl6s. With the following pigments, he paints a spec-
trum, which shows all the colors, either by gas or candle-light ; but
shows only black and white, with a soda flame (alcohol and salt) .

Color by daylight. Pigment. Color by soda flame.

Red, Ochre, Black.

Orange, .... Biniodide of mercury, > TVVi'fa

Yellow, .... Chromate of lead, 5 * * "^'*^'^®'

Green, .... Manganate of baryta, > -ni .i.

Blue, Aniline blue, ^ * * ■^^^°'^-

11*

126 ANNUAL OF SCIENTIFIC DISCOVERT.

NEW INSTRUMENT FOR MEASURING DISTANCES.

Dr. Emsmann, in a paper in " Po<^gcndorfrs Annalen," de-
scribes a new instrument for measuring distances, whicih difVers
from all previous arrangements, by being independent of tlie
measurements of angles, or of a base line. It consists, simply, in
an application of the well-known principle, that the image of an
object is brought to a focus by a convex lens at a distance from
the lens varying according to the i-cmoteness of the object. The
aiTangemont descril)ed by Dr. Emsmann consists of an oliject-
glass of thirty seconds and an ej'e-piece of one S(!Cond focal length,
a screen of ground glass, upon which tlie image is received, being
placed behind the eye-piece. The instrument, it will be seen, re-
sembles in principle a photograph camera; the length, however,
is about five and one-half feet. In order to k<M'p the indications
within certain limits, tlie screen is placed beliind the eye-piece,
and the distance between the lenses is so arranged that a varia-
tion in the distance of twenty-five i)aces, at all ranges, requires, at
least, a movement of one line in tiie screen. Trustworthj' readings
may be obtained up to two thousand paces. Dr. Emsmann sug-
gests that the instrument will be found useful in coast batteries, for
measuring the distance of a vessel out at sea. In siege operations,
the time g(!nerally admits of the measurement of a base line, the
distance of the enemy's works l)t'ing calculated by trigonometry.
Should there be no practical diflieulties in the wa}% it might prob-
ably replace, with advantage, the stadiometer, which depends on
the priiicij)le of similar triangles, supplied the army for use in
judging distance-drill.

THE CYCLOSCOPE.

In places where railways are most needed, but whei'e, owing to
disadvantages of the ground, and other hindrances, the transport
and use of large instruments is very difficult, an instrument at
once portable, and capable of replacing a theodolite in settingout
railway curves, becomes a desideratum. An instrument called a
"Cycloscoi)e," or curve-tracing instrument, invented and patented
by Mr. H. Temjjle Humphreys, associate of the Institute of Civil
Engineers, is calculated to meet this want, by measuring angles
and setting out railway curves with increased facility. It may be
shortly described as an instrument combining the advantages of
a pocket-sextant with the principles of a kaleidoscope. When the
two jDlane mirroi's of an ordinary pocket-sextant are turned toward
a distant oljject, so that by one combined reflection between both
mirrors a reflected image of the object is obtained, the angular
inten'al between the image and the object is twice the angle con-
tained between the mirrors. Reijeated reflections of the same
kind would, of course, produce a series of images, growing dim-
mer, arranged at the same angle from each other as the first
image fi-om the object. This is found to be the case when the
object is indefinitely distant. When the object is near, as in the
common kaleidoscope, and placed between the mirrors, it is seen

NATURAL PHILOSOPHY. 127

repeatedly reflected in the mirrors at equal intervals along the
circumference of a mathematically true circle, the centre of which
is the intersection of the mirrors. In all positions whatever, of
an object viewed by reflection with two plane mirrors, this actu-
ally remains true. The object appears the first of a series of
images arranged at equal intervals round the circumference of a
circle, the centre of which is the jooint of intersection of the mir-
rors with each other, or of the images, if need be, produced.
Of tlie two plane mirrors with which the cycloscope is entirely
composed, the front mirror is half silvered, and it is brought into
any convenient inclination with the entire mirror behind it, by
turning a screw. The parts of a I'evolution of the screw corre-
spond to minutes of a degree of inclination. When the last
chained peg of the straight line immediately preceding a railway
curve is seen directly through an eye-hole in the centre of the
entire mirror, its successive combined reflections at the same time
meet the eye at equal tangential angles, and trace out a circle, the
direction of the intended curve. The curve can then be set out
by pegs placed at equal chained distances apart, in the direction
of the combined reflections. By this means several points of a
railway curve can be set out at one sight, and the necessity of
repeated removal and readjustment of a theodolite in the ordinary
mode of setting out railway curves is avoided. The instrument,
which is made by Mr. Stanley, London, resembles a pocket-sex-
tant in being also a small and portable construction for measur-
ing distances and angles of moderate width. — Intellectual Ob-
server, May, 1866.

OPTICAL DELUSION.

Many of our readers will, no doubt, recollect "Eidos ^ides,"
which was performed at Her Majesty's Theatre during the win-
ter. It has been made the subject of a patent by the inventor,
Mr. Maurice, from whose specification we learn the manner in
which this clever delusion is produced. It is jDerhaps necessary
to say that it consists in causing an actor, or an inanimate object
which is in full view of the audience at one moment, to disappear
instantly, and then to reappear with the same rapidity. The
means by which this is accomplished are very simple, and are, to
some extent, similar to those used in exhibiting " Pejjper's Ghost."
A sheet of plain unsilvered glass is placed upon the stage, either
upright or inclined at a suitable angle, at the place where the ac-
tor or object is to disappear. This glass is not perceived by the
audience, and it does not interfere with their view of the scenery,
etc., behind the plate. A duplicate scene, representing that part
of the back of the stage covered by the glass, is placed at the wing,
out of sight of the spectators. With the ordinary lighting of the
stage, the reflection of this counterfeit scene in the glass is too
faint to be observed ; but when a strong light is thrown upon the
scene, the stage lights being lowered at the same time, the image
becomes visible. This duplicate scene being an exact fac-simile
of the baclvground of the stage, the change is not noticed by the
audience, the only difference being that they now see by reflec-

11^8 ANNUAL OP SCIENTIFIC DISCOVERY.

tion that which they saw a moment previously by direct vision.
The actor, standinG: at a sufficient distance behind the fj^lass, is
completely hidden tVom view, and he is again ri'ndered visible by
turning down the light on the false scene, and allowing the stage
lights to }5redominate. When "Eidos iEidcs" was being per-
formed at Her Majesty's Theati-e, it was, however, possible, with a
good ojiera-glass, to distinguish the outline of the figure behind
the plate. The effects produced may, of course, be modified. An
actor may be made to appear walking or flying in the air, or
dancing on a tight-rope, by eclipsing or obscming a raised platform
on which he may be placed. — Reader.

WHY BEES WORK IN THE DARK.

A life-time might l)e spent in investigating the mysteries hidden
in a bee-hive, and still half of the secrets would be undiscovei-ed.
The formation of the cell has long been a celebrated problem for
the mathematician, whilst the changes which the honey undergoes
offer at least an equal interest to the chemist. Every one knows
what honey, fresh from the comb, is like. It is a clear, yellow
syrup, without a trace of solid sugar in it. Upon straining, how-
ever, it graduall}' assumes a crystalline appearance ; it candies, as
the saying is, and ultimately becomes a solid lump of sugar. It
has not been suspected that this change Avas due to a photographic
action ; that the same agent which alters the molecular arrange-
ment of the iodide of silver on the excited collodion jjlate, and de-
termines the formation of camphor and iodine crystals in a bottle,
causes the syrup}' honey to assume a crystalline form. This, how-
ever, is the case. M. Scheibler has enclosed honey in stoppered
flasks, some of which he has kept in perfect darkness, whilst oth-
ers have been exposed to the light. The invariable results have
been that the sunned portion rapidly crystallizes, whilst that kept
in the dark has remained perfectly liquid. We now see why bees
are so careful to Avork in perfect darkness, and why they are so
careful to obscure the glass windows which are sometimes placed
in their hives. The existence of their young depends on the liquid-
ity of the saccharine food presented to them, and if light wei'e al-
lowed access to this, the syrup would gradually acquire a more
or less solid consistency ; it would seal up the cells, and, in all
probabilit}', prove fatal to the inmates of the hive. — Chronicle of
Optics, in the Quarterly Journal of Science.

NEW ARTIFICIAL LIGHT.

Mr. James Wilkinson, of Chelsea, is endeavoring to rival the
magnesium light for photographic purposes, by means of a mix-
ture of phosphoi'us and nitrate of potash. He recently burnt a
quarter of a pound of this mixture in his garden, at night, with a
view to obtain a photograph of a wind engine which was being
erected in an adjoining garden, and he states that " the length of
time from when it was first lit until it was finally burnt out, was
nearly six minutes. The utmost cost was a fraction over four-

NATURAL PHILOSOPHY. 129

pence. The reflection of the light might be seen for two miles
I'ound. So bright was it that the fire-engine authorities mistooli it
for an ordinary conflagration, and hurried their engines to the
spot. On finding no trace of the fire they returned, rather cha-
grined ; not, however, without first satisfying themselves by a thor-
ough examination of the premises. All around appeared one blaze
of liglit; the sky looked like a mass of fire." The 25icture taken
during this startling illumination " came out," we are told, "with
great sharpness and vividness, the houses near being brought out
prominently. It, in fact, equalled any picture taken on a bright
day." — IlecJianics'' Magazine.

THE MICRO-SPECTKOSCOPE.

The micro-spectroscope has received its first application to
medico-legal purposes, in the examination for blood stains of the
hatchet supposed to have been used in the Aberdare murder.
Dr. Bird Herapath, F.R.S., who was retained by the Crown,
placed sections of the handle in distilled water, and submitted the
solution obtained to an examination in this instrument. Within
the green, and on the border of the yellow raj's, the well-known
characteristic dark bands of blood were produced. Only one
other substance was known to produce similar dark bands, —
cochineal dissolved in ammonia, — in ■which case, however, their
position would be diflerent. Dr. Herapath said he was satisfied,
from the evidence this test had aflorded, that the hatchet had
been stained with blood.

INVISIBLE PHOTOGRAPHIC IMAGE.

M. Carey Lea of Philadelphia communicates to the " American
Joui'nal of Science," for July, 1S65, the following paj^er : —

" Some experiments in which I have lately been engaged seem
to me to finally settle the long-contested question as to the nature
of the invisible photographic image, and I hasten to send a very
brief description of them.

" The view that the change which takes place in an iodo-
bromized plate in the camera is a purely physical one, that no
chemical decomposition takes place, and neither liberation of
iodine nor reduction of silver, has obtained a pretty general
acceptance. But latterly it has been opposed by two distin-
guished photographers. Dr. Vogel and Major Russell. The for-
mer aflirms that iodid of silver is never sensitive unless there is a
body present capable of taking iodine from it under the influence
of light; and Russell l^elieves that the developed image is chiefly
produced at the expense of the silver haloid in the film. The
following experiments seem to me to decisively close this con-
troversy in favor of the physical theory.

'■'Experiment 1. — If the iodid or bromid of silver in the film
undergoes decomposition in. the camera, and, still more, if the
developed image is formed at its expense, the film of iodo-bromid
must necessarily be greatly consumed in the development under

130 ANNUAL OF SCIENTIFIC DISCOVERT.

the dense portions of the negative, which it has contributed to
form.

"To settle this point, I exposed and developed an iodo-brom-
ized plate in the ordinary manner. Tlien, instead of removing
the unchanged iodid and bromitl by fixing in tlie ordinary nianii(;r,
I tooic measures to remove the developed image witiiont allecting
th(! iodid and bromid. This I succeeded in doing with the aid of
a very weak sohitiun uf acid per-nitrale uf mercury. Now, if the
iodid, or bromid, or both, had been in any way decomposed, to
form or aid in forming the developed negative image, when this
came to be removed, there should have been left a more or less
distinct positive image, depending upon varjing thicknesses of
iodid ami bromid in the film, nuich like a fixed negative that has
been completely iodized. Nothing of this sort was visible ; the film
was perfectly uniform, just as dense where an intense light had
been, as in tliose parts whicii had scanvdy received any actinic
impression, and looking exa(;t]y as it diil when it first left the
camera, and before any developer had In^cn applied. This ex-
periment seems sufficiently decisive. But the following is far
stronger.

" Experiment 2. — A plate was treated in all respects as in No. 1,
except that the application of the nitrate of Jiiercury for removing
tiie developed image was made by yellow light. The plate, now
showing nothing but a uniform yellow film, was carefully washed,
and an iron developer, to which nitrate of silver and citric acid
had been adiled, was applied. In this way the original image
was reproduced, and came out quite clearly with all its details.
Now, as every trace of a picture and all reduced silver had Vjeen
removed by the nitrate of mercury, it is by this experiment
absolutely demonstrated that the image is a purely physical one ;
and that, after having served to produce one picture, that picture
may be dissolved oft', and the same physical impression may be
made to produce a second picture by a simple application of a
developing agent.

"I have repeated the experiment with a pyrogallic develop-
ment with similar results. Both the first and second develop-
ments may be made with an iron developer, or both with a
pyrogallic' The experiment succeeds without the least difficulty
in either way."

The same author, in " Silliman's Journal " for September, 1866,
concludes a paper on this subject, as follows : " I have endeavoi'cd
to show that the action of light upon pure iodide of silver isolated
cannot be a chemical reduction: 1. Because that effect, even
when carried many hundred thousand times further than in the
ordinai-y photographic processes, perfectly disappears in a few
hours, spontaneously, under circumstances which render it im-
possible to suppose that iodine could have been restored to replace
that which (had reduction taken place) must have been disen-
gaged. 2. Because, even where the action of light is prolonged
many hundred thousand fold the ordinary time, no reduced silver
nor sub-iodid can be detected as present. 3. I have shown that
another metal, mercury, is capable of developing these images

NATURAL PHILOSOPHY. 131

as well as silver. 4. I have endeavored to show that a purely
physical cause, to wit, mechanical pressure, is capable of produc-
ing a developable impression, thereby answering the objection of
the inadequacy of a physical influence to create a basis of devel-
opment. And, finall}', I may remark that although the chemical
theory is suj^ported by some distinguished chemists of the present
day, I am not aware that there is a single well verified experi-
ment which can be brought forward in support of that view. In
the absence of such, I have been necessarily obliged to confine
myself to the affirmative side of the question, in sujiport of the
existence of a physical image, distinct from chemical reduction,
and though often accompanied by it, yet never necessarily,"

PHOTOGRAPHY IN NATURAL COLORS.

M. Poitevin has lately succeeded in producing photographs on
paper in their natural colors. He prepares his sensitive paper in
the following way : Having obtained a layer of violet subchloride of
silver on the j)aper, by the action of light on the white chloride in
the presence of a reducing agent, he applies to the surface of the
paper a liquid composed of one volume of a saturated solution of
bichromate of potash, one volume of a saturated solution of sul-
phate of copper, and one volume of a solution containing five per
cent, of chloride of potassium. This paper is dried and kept in
the dark : it will keep good for several days. In this mixture, the
bichromate of potash is the principal agent ; the sulphate of cop-
per facilitates the action, and the chloride of potassium preserves
the whites which are formed. In copying paintings on glass, the
exposure to direct light need only last five or six minutes ; but the
time must, to some extent, depend on the transparency of the pic-
ture to be copied, and it is easy to watch the development of the
image on the paper. The paper is not sufficiently sensitive for
use in the camera. To preserve the pictures, it is only necessary,
first, to wash them Avith water acidulated with chromic acid, then
to treat them with water containing bichloride of mercury, after-
wards with a solution of nitrate of lead, and, lastly, well wash
them with water. After that they will not change in ordinary
light, but will, hoAvever, turn brown in direct sunlight. — Quart.
Journ. of Science, April, 1866.

PRINTING PHOTOGRAPHS IN COLORS.

Mr. J. A. Gatty read, on the 4th of October, at a meeting of the
Manchester Literary and Philosophical Society, the subjoined
paper, describing a process for obtaining colored photogra^ihs : —

" My process is based upon the property possessed by ferrocy-
anide of potassium, of forming clear solutions with certain me-
tallic salts, producing insoluble compounds when the mixture is
brought into contact with a deoxidizing agent: the ravs of the
sun acting as such, a perfect precipitation takes place upon pajjer
or other material ijrepared with the above-named solution. In
producing the specimens sent herewith, I applied to the paper a

132 ANNUAL OF SCIENTIFIC DISCOVERY.

concentrated solution, formed of equal parts of ferrocyanide of
potassium and nitrate of lt>ad, havin<; found tlio latter to answer
ver\' ^vt']\, not only as a means of fonnini; a jireeipitate, but also
for assistinji^ in tiie production of numerous colors. After dryinj^
the paper, it. was exposed to the sun for about lialf an hour, and
then washed in water in order to dissolve all the unaffected fer-
rocyaniile of potassium and nitrate of lead. I have notii-cd that
the sun acts much tjuicker when there is a little moisture present.
I have, therefore, placed a damp cloth between two or three
thicknesses of jiaper ijchind the prciiarctl paper. After washing,
tht^ photographic iinai^t; remains Itchind as a pale g'reenish pre-
cipitate, easily transformed into the various colors, as the follow-
ing experiments will show: —

" No. 1. (Ulue.) Has been steeped in a weak solution of nitrate
of iron for about ten minutes, and then wasiied in water.

"No. 2. (tireen.) Same as No. 1, but steeped in a weak solu-
tion of bichromate of potash alter the nitrate of iron.

" No. 3. (Reddish lirown.) Has been steeped in a solution of
nitrate of ecjpper, and then washed.

"No. 4. (Brown.) Has been developed by steeping it in a
mixture of weak solution of nitrate of iron and nitrate of copper.

" No. 5. (Dark Brown.) Has ahso been treated with a solution
of nitrate of iron and nitrate of copper, but containing a larger
pro])ortion of the former.

"Tiiese few experiments will show that a very large number
of shades may be oljtained by using diiferent salts an(l mixtui'es
thereof in develojnng the photograph. A further series of colors
may be oljtained i)y destro} ing the blue with caustic-soda, which,
after washing, will leave Ijchind oxides of iron and lead, which
may be dyed with vegetable coloring matters.

"All the al)ove exj)crimcnts were made about four years ago,
which goes to prove that the colors are permanent. I hope
shortly to be able to resume my experiments, and work the
process out more perfectly."

COLORED PICTURES BY THOTOGKArHY.

In 1838, Herschel was the first to publish a paper on the various
colors which chloride of silver is susceptible of taking under the
influence of certain colored rays (;f light. ]\Ir. Robert Hunt also
publi?lied,in 1840, a paper referring to the subject; but the most
complete series of researches on the subject of the i-eproduction
of the colors of the spectrum, and which led to a process by
which several of the colors of the spectrum could be pi'oduced
on a sensitive surface, is due to Edmund Becquerel. The results
arrived at by this gentleman Avere so remarkable that they drew
the attention of the whole scientific world ; and the following is an
outline of the processes which were applied by him to obtain this
interesting result. He took a daguen-eotype plate, or a silver-plated
one, and having dipped it in a weak solution of chlorine, or, what
was still better, a weak solution of hydrochloric acid, by connecting
it with the poles of a battery, the brilliant sUver surface acquii'ed

NATURAL PHILOSOPHY. 133

different tints, passing gvadualh" from an opaque white to a black
tint. He also observed that the tint best suited to obtain favorable
results was when the jDlate had acquired a pearlish pink; and,
although he found that the plate so prepared, when placed in the
camera obscura, assumed the colors composing the si^ectrum,
still they were faint ; but he remedied this defect of intensity of
tints by heating for several hours to a temperature of 95° to 100°
the chlorinated plate, and then submitting it to the influence of
the various colors composing the spectrum. Further, in the
course of his studies, he made the important observation that he
could replace the peculiar action of heat on his prepared daguer-
reotype plate, by exposing it to the rays of the sun under a sheet
of paper which had been steeped in an acid solution of suljiliate
of quinine. The effect of this was that the plate of silver as-
sumed an intense white color, nearly resembling that of paper;
while if the jsrotective paper had not been used, the silver plate
would have gradually acquired a dark tint, and would have lost
the whole of its sensitive properties, the protective paper having
the power of arresting completely the most refrangible rays of
light, especially those which are beyond the line H of the spec-
trum. Notwithstanding M. Edmund Becquerel's ardent hopes to
find a method which would enable him to fix on a sensitive sur-
face the various colors of the spectrum, still he failed ; for they
faded as soon as they were exposed to the direct rays of light,
and could only be preserved in obscurity. But there is one gen-
tleman who deserves great praise for the extraordinary persever-
ance which he has shown in this class of investigation. I mean
the nephew of the discoverer of photography, M. Niepce de Saint
Victor. Although I Avill not enter here into the details of these
valuable researches, as they can be found in the " Comptes Rendus
de I'Academie des Sciences," still I may just be allowed to state
that he has not only by the following process obtained far more
brilliant colors than those first produced by M. Becquerel, but
has succeeded in rej^roducing on sensitive plates the various
colors of colored surfaces, such as are presented by fabrics,
flowers, etc. ; and, fui'ther, he has lately been so fortunate as to
reproduce on his plates yellow and black tints, which had resisted
all previous attempts. To give you an idea of the facts arrived
at by this gentleman, I may state that he has succeeded in so
fixing upon sensitive surfaces the various colors of the spectrum,
or of colored surfaces, that they will bear the action of diffused
light for several days. In fact, I have seen photographs which
reproduce faithfully a small doll dressed up in various colors, and
in which even the most minute ornament could be traced ; and,
what is certainly not less interesting, was the reproduction of the
iridescent colors of the peacock's feather. To obtain these mar-
vellous results, M. Niepce de Saint Victor takes a daguerreotype,
or silver-coated plate, and dips it into a weak solution of hj^po-
chlorite of sodium, having a siDccific gravity of 1.35, until it has
assumed a bright pinkish hue. The plate is then covered with
a solution of dextrine, saturated with chloride of lead ; it is then
dried, and subsequently submitted to the action of heat, as in M.
12

134 ANNUAL OF SCIENTIFIC DISCOVERT.

Becquerel's experiment, or under the sci*een of sulphate of qui-
nine, also referred to above. The plate is then ready to be i)laced
in the camera obscura, and to receive the colors of tlic spectrum,
or representations of nature, such as flowers, as well as ecirtain
colors produced by man. Lastly, he succeeds in increasing the
stability of the colors develojied on the sensitive surface by cov-
erino^ the jdate with an alcoholic solution of gum benzoin ; and
M. Niepce gives the name of Heliochromy to this branch of
photography.

During his lengthened researches, ]\I. Ni6pce de Saint Victor
has made two series of observations, viz., that he can produce
with facility, on prepared plates, the binary colors of the spectrum,
viz., orange, violet, indigo, and green, if those colors are natural;
but, if they are artilieially i)n)duccd by the mixing of two of the
primary colors, as red and yellow, or orange and blue, or yellow
and blue, he cannot reproduce the binary- color, but only one of
the two colors employed by the artisan to j'rejiare them. Thus,
for example, he can reproduce the natiu'al green of malachite, and
the beautiful color known as Scheelc's green, but he cannot do so
with a mixture of Prussian blue and yellow chromate of lead, the
blue only reappearing. These facts enable him to exj^lain why, in
ordinary plii)t()grai)liy, the leaves of i)lants always appear l)lack,
and why, wlien iie attempts to fix on his i)lates the colors of leaves,
they have a bluish hue, the yellow portion of the color not being
reproducil)le.

M. Niepce has made another series of observations which de-
serve notice, viz., that when a plate, as prepared b}- his process,
is dipped in an alcoholic solution of substances susce2)tible of im-
parting a color to flame, such, for example, as strontia, which eom-
luunicates a red hue to it, or baryta, which gives a yellowish-green
color, the prepared plates, when exi)osed in the camera, will as-
sume the same color as the salt which they have on their surface
would impart to the flame of alcohol; and, if a salt of copjKn- be
used, which has the property of comnumicating a vari(!ty of tints
to the flame of alcohol, the plate also will assume a variety of tints
when exposed to the action of light ; and during a certain period
of his lengthy researches, ]M. Niepce availed himself of this curious
jihenomi-non to obtain colored plates in the camera. — Dr. Calvert's
Cantor Lectures.

ARTISTIC COLORING OF PHOTOGRAPHIC PORTRAITS.

So difficult is the task of training a good colorist, that even the
accomplished aitist feels his inalnlity in endeavoring to impart the
information necessary to those he is wont to train in the knowledge
whereby he is enaljled to produce almost inimitable rijsults.

Without attempting to go deeply into the philosophy of color,
analyticall^y or synthetically, it may not be out of place to give,
however slight, an idea of how to proceed in coloring a photo-
graph.

It is indispensable that you Avash the proof well with a sj^onge ;
or, better, as ever at your command, sweep your tongue across it
in order to remo\ e any traces of grease or starch.

NATURAL PHILOSOPHY. 135

To coloi" a good, dean print, you must, in the first wash on the
face, use as much gum as will bring it nearly, although not quite,
to the same gloss as the albumen surface ; this wash to be com-
posed of — for a i^erson of ordinary complexion — a combination
of rose madder and Indian yellow, or Venetian red alone. With
these colors judiciously applied, you can produce any comjDlexion,
from the highest glow of health to the most sallow ; the shadows
to be warm, and in every case glazed even more than the albu-
men surface. Sepia, neutral tint, burnt umber, chrome yellow,
and ivory black, if projjcrly used, will give that life-like brilliancy
which is characteristic of health or decay.

Should the photograph be clear and well defined, for draperies
and carpets use transparent, but, if the picture be deficient from
under-develojiment, use opaque. Of transparent colors for such
purposes use the following : crimson lake and burnt sienna, Prus-
sian blue and Indian yellow. Chrome yellow and Prussian blue
also make an excellent wash for draperies, although not purely
transparent.

For backgrounds, which should ever be made to softly recede
from the figure, the following colors may be used with much pur-
pose : cobalt blue, and a little Chinese white, which give a good
efi^ect and altogether a jjleasing result, vignetting it to your own
taste with sepia, or other browns. By way of finish, or to relieve
an otherwise poor ijroduetion, it is sometimes necessary to make
what is termed an introduction ; that is, a side opening in the
background, where a neat landscape may be lightly sketclied and
colored, comprised of water, land, and sky, or a bit of woodland.
These sometimes give a freshness to an otherwise dull picture, or
serve to exclude soiue of those hideous backgrounds so much dis-
played in cartes generally. But, in putting in draperies,- carpets,
plain or pictorial backgrounds, let them ever be subdued, and in
quiet harmony with the figure, the head of which should ever be
the principal attraction to the eye. — Scott Alexander, in Brit-
ish Journal of Photography.

DESTRUCTION OF PHOTOGRAPHS.

A suggestion of considerable value to photographers has been
made by Dr. Angus Smith, F.R.S. The cause of the destruction
of photographs, apparently by the action of time only, is gener-
all}' considered to be due in reality to the presence of a minute
quantitj^ of hyposulphite of soda remaining in the paper. Hither-
to, almost the only plan of getting rid of this agent has been long
and continuous washing in cold or hot water. Dr. Smith has sug-
gested oxidizing the hyposuli^hite of soda into sulphate of soda
(which is likely to be harmless), by means of dilute peroxide of
hydrogen. This has been little known to chemists, and even now
it is seldom obtained in its pure state ; it is, however, to be had
in solution, and in a state sufficiently strong for many important
purposes in analysis. Oxides, such as in the case of manganese,
Avhich will not fill till more highly oxidized, are, with advantage,
treated by it. The lower oxide may remain unobserved in a solu-

136 ANNUAL OF SCIENTIFIC DISCOVERY.

tion, and in a state of minuteness sufficient to keep it in suspen-
sion ; liut, at llic nioiut'ut of contact vvitli the peroxide of hydrogen,
it blackens and falls. When the peroxide is pouix'd into a solu-
tion of hy})i)sulphite of soda, the chanj^e is not observed, as there
is n<i C()lori'<l oxide to be formed; i)ut whrn a salt of barium is
afterward added, it is found tiiat sulphuric acid has taken the
place of hyposulphurous. The stren<;:th of the solution does not
re(juire to l)e nrn-at : that which is sold eont:iins about nint; v(j1-
unu's of availal)le oxyi^cn ; if dihiti'd a thousand times, a solution
is obtained capable of oxidizinj^ hy)>osulphites. It appears that
all the hyposulphurous acid is instantly converted. Peroxide of
hydroiren is in reality an oxide of water: when the oxyjjtui leaves
it to do its work, nothiiin^ but water is Itd't; nothiu<^ bciuj:!^ added
to be washi.'d out. The peroxide, as sold, contains a little acid
(sulphuric) ; when made alkaline, it does not keep so well. If a
drop is put upon a photojxraph, it very slowly bleaches; its use in
this \uidiiuted state is not recommended. A^^aiu, if the peroxide,
as sold, is neutralized, the bleaching does not take place, at least
in an hour, — an ample time. For neutralization, soda may be
used. — (Juarteiiy Journal of Science, July, 180G.

UNALTERABLE PHOTOGRAPHS.

The only mode hitherto known of producing unalterable photo-
graphs has bei'n by vitrification. ]M. renal)ert, however, recently
exhibited to the Academy of Sciences some which, though n(jt
vitrified, are so indestructible that it is impossible to remove them
from the glass, so as to render it capable of being used a second
time. The ojialine glass employed in the pi-ocess, having been
well cleaned, is to be coated with ordinary collodion that is at
least a year old ; it is then to be plunged for a few minutes in a
sensitizing bath, which contains seven grammes of nitrate of sil-
ver to one hundred grammes of distilbnl water, and sixteen
grammes of pure nitric acid to one thousand grammes of the sil-
ver solution, and afterward to be exposed for about fifty seconds
in the camera. The developing fluid consists of a solution of jiro-
tosulphate of iron, containing two-thirds more Avater than that
ordinarily used, and one-lifth i^yroligneous acid. The positive
picture thus obtained is fixed by a weak solution of hyposulphite
of soda, and is intensified by a very weak bath of sulpliuret of
ammonium. — Intellectual Observer, February, 18GG.

A NEW PHOTOGRAPHIC WASHING APPARATUS.

The majority of eases of photographic fading may be traced to
the hyposul^jhite of soda, which, by so intimately associating itself
with the fibres of the paper, is difficult of removal, and Avhich, if
not perfectly removed, induces an action by virtue of which the
print eventually becomes destroyed. To remove the hyposulphite
of soda in the most perfect manner, and in the shortest time pos-
sible, is to insure to photographs a longer tenure of existence than
they would otherwise have held; and any means by which these
requii'cments can be met are entitled to the greatest consideration.

NATURAL PHILOSOPHY. 137

An instrument, invented and patented by Mr. Jolin E. Grisdale,
is capable of washing a full charge of prints in twenty minutes,
and that so jjerfectly, that at the end of this time some ordinaiy tests
for hyposulphite of soda fail to indicate its presence. " My inven-
tion," lie saj^s, "relates to a peculiar construction and arrange-
ment of centrifugal machinery or apparatus for washing photo-
graphic prints, and consists, according to one ai'rangement, in the
employment of a peculiarly-constructed revolving drum in comlji-
nation with a trough, in which such drum is partially immersed.
The prints to be washed are taken from the Avater in which they
have been placed on their removal from the fixing or other bath,
and are packed in one or more piles, which piles are jjlaced round
the circumference of the drum, each pile being composed of alter-
nate prints and sheets of wire gauze, or other open or reticulated
fabric, so that no two prints shall be in contact with each other.
These piles ai-e held in their places on the drum by means of open
frames or gratings, which bear against the opposite surfaces of
each pile, and are secured to the arms of the drum by screws or
otherwise, the whole or a portion of such frames or gratings form-
ing a i^art of the drum itself. Or, according to another arrange-
ment, the piles above described may be laid ilat upon a disk, which
is made to revolve either vertically or horizontally in a trough or
cistern, provision being made in the horizontal arrangement for
allowing the piles to be brouglit in or out of contact with the wa-
ter as required ; or, in lieu of the jjliotographic prints' being dis-
posed in the form of piles or packs round a drum or revolving disk,
they may be laid separately and individually round the surface of
a drum, a webbing of oi^en or reticulated faljric being wound on
such drum simultaneously with the placing of the prints thereon,
so as to inteqiose a thickness of the fabric between each succeed-
ing layer of prints. The process of washing consists in alternately
driving out the moisture from tlie prints by the centrifugal action
of the revolving' drum or disk, and saturating the prints again.
During the first part of the process, the prints are not immersed ;
but when the second part of the process, namely, the saturation, is
to be effected, the trough or cistern is to be supplied with water;
or the prints may be brought down into the water, and caused to
revolve therein and thoroughly saturated, when the water may be
run off from the trough again, or the drum or disk elevated, and
the moisture expelled by centrifugal force as before."

Freshly-supplied water is forced through every pore of the
prints, the consequence being the elimination of every trace of
hyposulphite of soda in a very brief space of time, — British Jour-
nal of Photography.

PHOTO-LITHOGRAPHY "WITH HALF-TONE.

The production of printing surfaces on stone, zinc, etc., by the
agency of photography, has occupied the attention of experimen-
talists for many years ; and, in many respects, a high degree of
success has been obtained. The process of Mr. Osljorne, for the
woi'king of which a company has recently been formed in Amer-
12*

138 ANNUAL OF SCIENTIFIC DISCOVERY.

ica, gives results in line and stipple, which leave little to he de-
sired. i\Ir. llaniar^e of Edinburj^h, Mr. Lewis of I)iil)lin, Colonel
James, and many otiiers, have also attained great excelk'ncc in the
same direction. Messrs. Simonan and Toovey of Brussels, have
attained some success in the i)roducti(>n of half-tone; and the
attempts of Col. James in the same direction have not been
without promise. Still, the fact remains, that no process for tlie
actual production of photograjjiis from nature by means of plioto-
litho,i;rapliy is in practical working, or has liitlierto establislicd a
position, and that sucli a i)rocess remains an important desidera-
tum, any means of meeting which would be hailed with a glad
welcome by all concerned in the graphic arts.

Unless we are mistaken in our estimate of a series of specimens
belore us, by Messrs. Bullock Brothers of Leamington, a process
which they have recently patented bids fair to meet the long-felt
want most successfully, and to render, with a fair amount of
delicacy, the true photographic gradation of negatives from na-
ture. The subjects before us, consisting of hmdseapes with
variety of foliage and arcJiitecture, are exceedingly excellent,
and jn-esent all the good points of a good photograph, perfect
gradation and half-ton(>, and great l>rilhancy, dilfering little in
general efleet from good silver prints from the same negatives.

Messrs. Bullock liave followed in i)aths already partially trod-
den, but have made such practical deviations and modifications
as have led them to success where others have only failed. Their
aim is to secure in the transfer a suitable grain, so as to obtain
the kind of gradation possiljle in lithograpiiy, without producing
a coarse or woolly effect. Among the various methods by which
they propose to eU'ect this end, the plan used in jjroducing these
examples seems to be at once the most practical and eilicient.
A transfer paper is prepared with a plain solution of gelatin, and
when this is dry a grain is printed on it from an aquatint 2>l'i^te.
Paper so prejiared can be kept in stock, and rendered sensitive
when required by immersion in a solution of bichromate of potash.
It is then ready for printing and transferring in the usual manner,
and produces on the stone a photographic image, the continuous
gradation of which is broken up into the stip2:»led gradation of an
aquatint plate. This is tlie broad princiiJle ; but it admits of
much ingenious modification in practice, which is so far eti'eetive
that it produces the most successful and pi'omising examples of
photo-lithogra])hy with half-tone which we have yet seen. — Lon-
don Photographic News.

PHOTOGRAPHY AND THE KALEIDOSCOPE.

About a couple of years ago, a writer in an excellent trans-
Atlantic cotemporary, the " Scientific American," remarked : " Let
the photographer once combine the kaleidoscope with the camera,
and then see with what ease and rapidity he can produce the
most charming designs for dress goods, tapestry, oil-eloth, wall-
paper, and numerous other purposes. Such a thing is possible."
Almost at the same moment that the American writer stated this,

NATURAL PHILOSOPHY. 139

M. I'Abbe Laljorde brought under the attention of the French
Photograi^hic Society a method which he had adojited to effect the
preservation, by photography, of the changeful designs of the
kaleidoscope. As a means of preserving patterns for a variety
of decorative purj^oses, this application of photography is deserv-
ing of attention ; and it may be interesting here to quote from the
communication of M. TAbb^ Laborde on the subject. It is worthy
of remark, that the method of throwing the designs of the kalei-
doscope on a screen by the aid of the magic lantern has since
been adopted and exhibited at the Polytechnic Institution : —

"The variety of designs presented by the kaleidoscope, when
turned round, is familiarly known to every one ; yet we are often
surprised at the appearance of very curious and unexpected forms
which we see disappear with regret.

"The regular figures which result are depicted on the ground
glass of the camera of long focus, and the images are focussed
direct without being reflected. This portion is naturally more
lighted than the others. It requires several minutes of exposure
to obtain a picture on the coUodioned plate. We cannot focus
the portions of the image which are several times reflected ; for
they appear in the objective as if they came from greater dis-
tance : they lack distinctness, and they"^also exhibit the defect of
planitude in the mirrors.

"Notwithstanding these imperfections, I believe I have at-
tained the aim I proposed to myself, which is, to place before the
eyes of those who are occupied with stained glass, paper hang-
ings, and other kinds of ornamentation, very varied patterns,
which photograjihy can supi^ly by the hundred." — Photograpliic
News.

PHOTOGRAPHIC PRINTING PROCESS FOR PRODUCING COPIES OF
BOTANICAL AND OTHER SPECIMENS.

A paper, by Mr. Henry Brightman, was read at a meeting of
the Bristol Naturalists' Society, December 7, 1865, proposing a
ready method of copying leaves, etc. He says: —

" To lay plants, etc., upon prepared paper, and expose them to
sunlight, was a method which had been frequently practiced ; but
the pictures so obtained were, technically, negatives, the rej)re-
sentation of the object being white, on a dark ground. It oc-
curred to the author, that, if these could be rendered transparent,
positives might be printed from them. He found, however, that
this could be readily done without any previous preparation of
the negative ; and he exhibited a number of very beautiful photo-
graphs, produced in this way, of ferns, leaves, and even a butter-
fly]s wing, showing the wide applicability of the process." Mr,
Brightman then described the process in detail ; for the negatives,
the albumenized paper should be as thin and free from grain as
possible, and sensitized by floating on a sixty-grain solution of
nitrate of silver. An ordinary printing-frame was used; but a
very long exposure was requisite, especially for positives; and
this constituted the chief objection to the process, where many

140 ANNUAL OP SCIENTIFIC DISCOVERT.

copies Avci'e roquired, as for illustrating a book. The toning bath
oontaiuod half an ounce of acetate of soda to one 2)int of water,
and one grain of eliioridt^ of gold for each sheet toned. The
I)ieture was fixed witli hvposuli)hite of soda (eight ounces to the
l)int), and well washed with water.

Much conversation then took place on this paper, in the course
of whii-h ]\Ir. Bcadic urged the employment of waxed paper,
instead of albunuiiized, as likely to give a more transparent
negative, and spoke of the ajiplication of carbon-printing to this
process. Mr. Brightman suggested the use of a green instead of
a black pigment in that method, to give the natural color of the
plant.

PHOTOGRAPHING CANNON BALLS.

Some months ago, when on a visit to Woolwich Arsenal, we
were shown Ijy Mr. M"Kiiday, Proof Master, some iihotograjihs
taken of guns while being lired, which not unnaturally excited
feelings of surprise. So rapid had been the exposure, and so
well had the i)ropcr moment for tin; cx])0surc been seized, that
the projectile couhl be seen jjrotrnding from the cannon's mouth
Avhile in the act of proceeding on its distant mission. Mr. M'Kin-
lay kindly alVorded us every requisite information relative to his
invention for securing such won<lerful results; and, from the fact
that tiie com2)arative eiru-ii'nc\- of certain kinds of small-arms, and
the intluence they are now exercising in European affairs, are at
present receiving a large share of public attention, we think that
it may not prove uninteresting to luring before our readers some
matters of scientilic interest in connection with our own " great
guns," and the means employed for ascertaining by photograjjhy,
and with the utmost possiljle precision, not only the jiath of a pro-
jectile in the air, but the time occu^jied in its progress between
two or more points anywhere in the course of its tlight. It will
be obvious that, when it is desired to ol)tain a photograph of a
gun at the moment of discharge, the gun itself must be made sub-
servient to the exposing and coveiung of the sensitive plate. It is
impossible that any person, however delicate his eyes and ears
may be, can operate so dexterously as to stop the exposure when
the ball has been projected, say a few inches from the muzzle of
the gun, and when it is consequently travelling at its greatest
velocity. This can only be accomplished by automatic arrange-
ments, aided by electricity.

Let us now suppose that a stereoscopic camera, fitted with pow-
erful lenses of short focus, has a thin, light disk fitted up in front
of the lenses, revolving on an axis between the two lenses. Two
holes in this disk correspond with the apertures of the lenses, so
that if a circular spring — like that of a pair of snuffers — cause
the disk to make half a revolution with great rapidity, the holes or
apertures will, when flashing i^ast the apertures of the lenses,
admit the light for an exceedingly brief jjeriod of time. This is
the means employed in the arsenal for effecting the exj)osure of
the plate.

We shall now enter into the details of the manner of discharg-

NATURAL PHILOSOPHY. 141

ing and arresting the circular exposing diapliragm. The opening
and shutting of the camera at the j^recise instant of time is, as we
have said, by far too nice an operation to be accomplished by
hand. It must be borne in mind that a gun commences to recoil
as soon as the i^rojectile is fairly clear of its muzzle. The picture
which Ave examined had been taken when the projectile was yet
emerging from the gun's mouth, and before it had got quite clear
of it, and consequently before the recoil of the gun had com-
menced. The exposure was very rai;)id, but not so much so as to
show the front edge of the emerging projectile with a sharp out-
line. Although the gun, from the recoil not having commenced,
was quite sharp, the front edge of the projectile was, so to speak,
vignetted.

The gun is fired by means of the galvanic tul^e invented by Mr.
M'Kinlay, and such as is used in pi'oving ordnance. Inside of
this there is a small platinum wire, which, when a current of elec-
tricity is passed thi'ough it, instantly becomes red hot, and melts.
Let us now see how this affects the operation of photographing
the gun. When the gun is ready for firing, the disk in front of
the lenses is wound up so that the rotating force of the spring in
the centre is at its maximum. It is retained in this position by
means of a catch and trigger, the latter of which is operated on
by means of an electro-magnet. The following, then, is what
takes place : When the galvanic current is sent through the wire,
the fine platinum wire imbedded among the gunpowder of the
discharging tube or fuse immediately becomes red hot, and melts.
But, while in jirogress of melting, it accomplishes two things ; it
transmits a current through it by which the electro-magnet be-
comes vivified and pulls the discharging trigger of the disk in
front of the camera lenses ; and secondly, it ignites the gunpow-
der and discharges the gun. But were this all, the exposure
would be made before the powder had had time to ignite and
consequently discharge the gun ; hence it is important that the
lenses be kept open until the gun really discharges its contents.
The means for effecting this are as simple as they ai'e ingenious
and complete. When the trigger acts so as to release the disk
from its enforced pent-up condition, it is pro^jelled forward by the
central spring until the apertures in the disk and those of the
lenses coincide, where, by means of a stop, the disk is retained
until the powder is ignited and the gun discharged, when, the
platina wire being ruptured, the passage of the electricity is
stopped, the electro-magnet simultaneously losing the power by
which it was enabled to arrest the rotatory progress of the disk,
which thus darts forward and closes up the camera as the con-
tents of the gun are in the act of being ejected from it. — British
Journal of Photography.

STATISTICS OF PHOTOGEAPHY.

The rapid gi'owth of new and special industries, says the "Brit-
ish Quarterly Review," is a fact so characteristic of the present
day, that the statistics of photography can scarcely be regarded as

142 ANNUAL OP SCIENTIFIC DISCOVERY.

woiulorful, viewed moi-ely as a question of economies. Neverthe-
less, some of tlie fai-ts are sufficiently startling. Twenty years a<2:o,
one person elaimrd the sole right to praetiee piiotogi;i])liy i)rol'es-
sionally, in Knglaiul. Aecording to the census of ISGl, the number
of persons who entered their names as photoyrai)lu'rs was 2, Hoi.
There is reason, however, to believe that these ligin-es fall short of
the real niinilti'i-. Sinee tlu-u it is probable the number has been
donljled or trebled, and that, inehiiliiig those collaterally associated
with the art, it is even four or live times that number. But these
figures fall far short of the number interested in photography as am-
ateurs. We are informed that eight years ago, in estaijlisliing a
j)enodieal whieh ha-; since become the leading ph<)togra])hic jour-
nal, a large j)ubli>hing lirm sent out twenty-live thousand circulars
— not sown broadcast, but specially addressed to persons known
to ije interested in the new art-science. The nimiber of professional
piiotographers in the United States is said to be over fifteen thou-
sand, and a proportionate number may with propriety be estimated
as spread over continental Europe and other i)arts of the civilized
glol)e.

But a more curious estimate of the ramifications of this industry
may be formed by a glance at the consumption of some of the ma-
terials employed. A single firm in London consumes, on an aver-
age, the whites of two thousand eggs daily in the manufacture of
allnunenized paper for photographic printing, amounting to six
hundred thousand annually. As it may fairly be assumed that this
is but a tenth of the total amount consumed in this country, we
obtain an average of six millions of inclKKite I'owls sacrificed annu-
ally, in this new worship (tftiie sun, in the United Kingdom alone.
"NViien to this is added the far larger consumption of Europe and
America, which we do not attempt to put in figures, the imagina-
tion is startled by the enormous total inevitably presented for its
realization.

In the absence of exact data, we hesitate to estimate the con-
sumption of the precious metals, the mountains of silver and mon-
uments of gokl, which follow as matters of necessity. A calcula-
tion, based on facts, enables us to state, however, that for every
twenty thousand eggs employed, nearly one hundred weight of
nitrate of silver is consumed. We arrive thus at an estimate of
three hundred hundred weight of nitrate of silver annually tiscd in
this countr}' alone in the proiluction of photographs. To descend
to individual facts more easily grasped, we learn that the eon-
sumption of materials in the photogi'aphs of the International Ex-
hibition of 1802, produced by Mr. England for the London Stereo-
scopic Company, amounted to twenty-four ounces of nitrate of
silver, nearly fitty-four ounces of terchloride of gold, two hundred
gallons of albumen, amounting to the whites of thirty-two thou-
sand eggs, and seventy reams of paper ; the issue of pictures ap-
proaching to nearly a million, the number of stereoscopic prints
amounting to nearly eight hundi-ed thousand copies. — Scientijic
American.

NATURAL PHILOSOPHY. 143

ANILINE PROCESS OF PHOTOGRAPHIC PRINTING.

Mr. W. Willis of Birmingham has recently laid before the
Photographic Society an account of his aniline process of photo-
graphic printing. It consists of a new method of developing the
pictm'es produced by Hunt's chromatype process, in which the
paper is prepared with a solution of bichromate of potash and
sulphate of copper. The difficulty of finding a suitable develoijcr
for the prints so obtained has hitherto prevented the use of this
method. The em^jloyment of nitrate of silver or mercury, besides
being attended with some jiractical inconveniences, i^roduces pic-
tures of a red color, which, although suitable for the reproduc-
tion of the red chalk sketches of the old masters, is inadmissible
for ordinary drawings. According to Mr. Willis's process, the
paper is sensitized with a solution of bichromate of potash or
ammonia, containing a small quantity of sulj^huric or phosphoiic
acid, and, when dry, is exposed to light under a positive photo-
graph or drawing. It is then placed over a solution of aniline in
benzole, turpentine, or ether, preferably the former. The parts
forming the picture — i. e., those not acted ujion by the light —
arc developed of a mauve color, which is very permanent, not
being changed in tint by the application of acids or alkalies. The
process has already been introduced in Birmingham for the mul-
tiplication of engineers' drawings, in cases where the number
required is not sufficiently great to admit of lithography being
used with advantage. The property i^ossessed by bichromate of
potash of forming a black compound with a solution of logwood,
which has been used for the manufacture of cheap writing-ink,
has also been aj^plied by Mr. Fox of Edinburgh to the develop-
ment of these chromatype pictures. Both these processes have
been secured by patent.

A new solvent for the greater part of the aniline colors has been
discovered by M. G. de Claubry, and communicated by him in a
pajier to the French Academy of Sciences. In jjlace of alcohol
and methylated spirit, which are high-priced or injui'ious to the
workmen, M. de Claubry proposes to substitute a decoction of
Panama bark {Quillaria), or of Egyptian soap- wort (Gypsophila) .
Solutions of the coloi'ing products can be easily obtained by pour-
ing the boiling decoction upon the powder-, after stirring and
decanting the solution, the operation must be repeated, if any
part of the powder remain undissolved. It was found that the
red colors dissolved most readily, and the blues less so. If, there-
fore, the coloring matter be purple, it is necessary at the end to
mix the different solutions together in order to obtain a dye of
the right tint.

IMPROVEMENTS IN PHOTOGRAPHY.

Photosciilpfure. — A process is now in use in London liy which
busts, statuette likenesses, etc., may be produced in clay or plas-
ter at a small cost, by the aid of photography. The operation is
as follows : Eight photographs are taken of "the sitter from eight

144 ANNUAL OF SCIENTIFIC DISCOVERY.

sidos ; from oac-li of these, profiles are cut out in thin sheet metal ;
eacli pair of prolilus is caused to i)lane away tiie sides of a Ijlock
of clay coiTcs])onding to the position in which their photograph
"was taken. I'lius, the clay conies to have on each side tlie same
jjrofde as that of the sitter, and is tlius a likeness rccjuiriiig but a
few toueiies from tlie artist to give it finish and exactness.

The " carl)on printing" photograplfit; jjnxx'ss has been applied
to the ijcrmanent ornamentation of porctdain with success ; any
material fit for l)urning into that su!)stance being sul)slituted for
the carbon or India inl< of the original operation. — Frunklia Jour-
nal, January, 18G6.

P/iottiipapJis iifthe Moon. — Mr. Warren De la Hue has obtained,
with ins tinrtccn-inih telescope, i>hotograplis of tlu; moon so ]jer-
feet that they l)car being cnlargcil to a iliameter of three feet ; and
they are foun<l so exact, w ht-n submitted to microuietrical exami-
nation, that they furnish correct data for the measurement of the
vibrations of the moon. They also serve as a foundation for the
lunar map, six fc»'l in diameter, undertaken under the auspices of
the British Association.

New Artifi<i(tl Liijhifor PJiotofji-aphy. — 'Mr. Savers of Paris ob-
tains a ligiit almost ei[ual in power to that of magnesium, and
unich cheaper, from the comliustion of a mixture of twenty-four
jiarts of well-drii'd and powdered nitrate of potash with seven of
flowers of sulphur and six of red sulphuret of arsenic. The mix-
ture costs only twelve cents a kilogram. — Lcs Mondes, Jan. 4, 18GG.

Light for P/totoyraphic Purposes. — A substitute for the yellow
glass, used by photographers to intercejit actinic rays, lias beea
suggested by W. Sidni'V (ribbons of Melbourne. This is a mix-
ture of gelatin and bichromate of jjotash, spread as a varnish
over their cotton cloth or similar material.

In 2)reparing a window for the illumination of a photographer's
dark room, Oliyrnetter mixes an acid S(dution of sulj^hate of qui-
nine with some gum or dextrine, and paints the mixture over a
thin sheet of white paper. With this he covers the window
panes, and he states that, on the brightest day, a window so pre-
pared will allow no actinic light to pass.

Varnish for Photographs. — ^I. liussi first brushes the pi'ints
over with a solution of gum araliic, and, when this is dry, applies
a coating of collodion. The following are the i)roportions re-
commended : —

1. Clear transparent gum arabic, 25 grammes; distilled water,
100 cub. cents. ; dissolve and strain.

2. Gun-cotton, 3 grammes ; alcohol, 60 grammes ; ether, 50

grammes

By this double varnish the inventor insures the preservation of
proofs. — Chemical News.

Magic Photographs. — The familiar exi5criments of the labora-
tory have in the present day a great tendency to become the
magic of the drawing-room. Magic photographs are among the
most recent of the scientific toys which take the public attention.
These are of various kinds. The first and most common mode
of producing them consists in placing an apparently common

NATURAL PHILOSOPHY. 145

piece of blotting-paiier upon an apparently plain piece ot white
all)umenized paper, moistening tiie two, and producing at once a
photographic picture. The explanation of this is simple, and is
doubtless familiar to old photographic experimentalists ; we prac-
ticed the same feat a dozen years ago. It consists in bleaching,
until it is white and invisible, by means of bichloride of mercury,
a silver print; then, taking a piece of blotting-paper which has
been previously immersed in a solution of hyposulphite of soda,
and placing it in contact Avith the immersed print; this, when
moistened, at once darkens the bleached image, and a picture,
consisting chiefly of sulphide of mercuiy, is i^roduced. We have
received some examples from Mr. Swan, and details will be
found in Dr. VogePs (xcrman letter in this number. We have
just received from Mr. Hughes's establishment a still prettier
ajjplication of parlor magic, in which, by placing an apparently
blank piece of paper in a solution — the material for which is
inclosed in the packet — a beautiful blue print is produced. This
is doubtless the result of one of the applications of the Cj'anotype
process of Sir J. Herschell, which may be made to produce many
beautiful transformations. — Photographic News.

The Magic Photograph is selling in Paris and London, in two
envelopes, one containing pieces of white albumenized paper;
the other, slips of white blotting-paper of a corresponding size.
One of the former is moistened with water, and a piece of jiaper
from the other envelope, likewise wetted, is laid thereon, when a
beautiful photograph is immediately developed on its albumenized
sui'face. Photograplis have, of course, been printed in the usual
manner on the albumenized slips, and then decolorized with
bromic or iodic acid, or some such agent; the other i^ieces of
pajjer have been soaked in hyi^osulphite of soda, and the appli-
cation of this reducing agent to the hidden photograph instantly
brings it again to view.

SUBMARINE PHOTOGRAPHr.

A French artist, M. Bazin, has been experimenting lately, with
the design of obtaining photographs of sunken vessels, so that, in
attempting to raise the same, positive knowledge can be had of
their relative positions. To accomplish this, M. Bazin descends
to the necessary depth, in a strong sheet-iron box, which he calls
his "photographic chamber." Thick glass windows afford every
facility for making the necessary preliminaiy observations, and
the picture is taken by the aid of a strong electrical light.

An unpleasant feature of the apparatus is, that the oj^erator is
absolutely hermetically scaled, for no means are provided for sup-
plying air, the chamber being constructed of a proper size to con-
tain the quantity required during the ten or twelve minutes
occupied in obtaining a negative.
o

146 ANNUAL OF SCIENTIFIC DISCOVERT.

SUBTERRANEAN PUOTOGRAPUY.

A firm in Cincinnati have obtained the exclusive rijjht of takins:
views in the Mammoth Cave of Kontueky fi)r five years. The
process suecossfully used in takinj; pictures of the interior of the
Great Pyramid is adopted, usin;^ tl>t^ magnesium liglit. The
dampness of the cave, the smoke arisini^ in tiie consumption of
hirjre quantities of map^nesium, the diverjrency of tiie artificial
lijriii, and the majrnitude and proximity of th(^ ohjeets to be ph(j-
tojrraphcd, present a number of serious dilliculties. Powerful
rcilectors are used U) tiuow a Hood <jf ligiit upon tiie objei-t, and
the i)late is allowed about twice the exposure required by the
light of the sun.

rUOTOGRArilING UPON SILK.

A process has been devised at Lyons, France, for jihotograph-
ing upon silk, linen, etc., so that jH-rsons instead f)f mai'kiiig tlicir
initials upon the corner of a handkerchief, can have tlieir plioto-
graphs taken upon the fabric. In the silk shops, various articles
are exhibited, ]ihotogra])hcd with names, i)ortraits, and fanciful
devices. Tiie pictures are not injured by washing, and the pro-
cess is said to be easily aud rapidly effected.

PllOTO-MICOGRAPIIY.

Dr. J. J.Woodward, U. S. A., in a jiaper communicated to
" Silliman's Journal," for September, 1866, on the subject of jiho-
tography of microsco])ic objects, gives the following as the prin-
ciples involved: 1. To use ol)jectives so corrected as to luring
the actinic ray to a focus. 2. To illuminate by direct sunlight
jjassed tlirongli a solution of ammonio-sulphate of copper, which
excludes practically all but the actinic extremity of the spectrum.
3. Where it is desired to increas*; the power of any olycctive, to
use a i)r(jperly constructed achromatic concave, instead of iin
eye-piece. 4. To focus on plate glass with a focussing glass
instead of ground glass. 5. With high powers, to use a heliostat
to preserve steady illumination. 6. Where an olnject exhibits
interference phenomena when illuminated with parallel rays, as
is the case with certain diatoms, and many of the soft tissues, to
produce a proper diflusion of the rays by interposition of one or
more plates of ground glass in the illuminating pencil. Strict
adherence to these principles is indispensable to success. The
most powerful objective with which photographs have been taken
for the Army Medical JMuseum, was 1-50, made by Messrs. Powell
and Lealand of London. The subject selected for the experi-
ment was Pleurosifjma angulatvm ; with 1-50, and 3.| feet distance,
and without an eye-piece, a picture of a portion of a frustule was
obtained, magnified 2.344 diameters; this negative readily bore
enlargement to 19.050 diauu'ters ; the field in the picture is 6
inches in diameter, and is remarkal)ly sharp in the centre, but
shows considerable curvature, aud ou the edges is quite out of

NATURAL PHILOSOPHY. 147

focus. These photographs confirm the opinion of Mr. Wenham
and Prof. Rood, as to the cirouhir nature of the markings on P.
angulaium. It is remarkable that the markings appear hexagonal
in both the small pictures, if viewed with the eye at the visual
distance ; while on close inspection, or with a lens, they are seen to
be circular in the pictures; with 19.0J0 diameters, the circular
shape of the markings is ver}- plain, but, if viewed from a coa-
siderable distance or with a concave lens, they appear hexagonal.

NEW n^LUMINATOKS FOR OPAQUE OBJECTS.

H. L. Smith, of Kenyon College, contributes a paper on this
subject to " Sillimans' Journal," for September, 1865, from which
the following are extracts : —

" In attempting to study the structure of the diatomaceous frus-
tule, I found it impossible to view it with high powers as an opaque
object by any means hithei'to devised. In a valuable paper on
the scales of the podura (' Mic. Joui'.,' N. S., vol. 2, p. 8G), Mr.
Richard Beck has stated that there is no diiBculty in viewing them
as an opaque object, with the one-eighth-inch objective and con-
densers righth* placed. Any illumination of diatoms thus ob-
tained is almost useless, from the great obliquity of the light,
and, with powers higher than the one-eighth-inch, is quite impos-
sible. Mr. Ross's ingenious arrangement, suggested by Mr.
Brooke, of a plain retlector, flush with the front surface of the
objective and receiving light from a truncated ellipsoidal reflector
below, is so exceedingly diflicult to use, and only with a special
mounting of the object, that it has never been generally adopted.
Mr. "NVenham's method is entirely inapplicable to diaroms, inas-
much as it depends upon the total reflection of the light from the
under surface of tlie glass cover of a mounted object, and in such
case the diatoms, from their transparency, and the near coinci-
dence of refractive index of silex with that of the mounting fluid,
throw back but a feeble light, and are nearl}- invisible. The use of
the well-known collimating eye-piece suggested to me the idea of
making the objective its own condenser; and upon communicating
this idea to ilr. Wales, already well known for the excellence of
his objectives, he at once sent me a trial instrument. This first
illuminator proved so far successful that I was induced to perse-
vere; and, with his assistance, an 'illuminator' has been con-
structed which gives entire satisfaction, and answers admirably
with all objectives from four-tenths to one-fiftieth.

" It must be borne in mind that there are certain difficulties to be
overcome in this mode of illumination, the chief of which is the
reflection of the light from the posterior surface of the back com-
bination of the objective. All the difiiculties are now surmounted,
and there is no trouble in viewing diatoms, or other objects,
mounted dr}-, and uncovered, with tiie highest powers of the mi-
crosco2Je, and with- abundant illkmiination ; and this without any
trouble in mounting the object on little disks or pins, but using
the ordinary three-inch by oue-ineh slide.

148 ANNUAL OF SCIENTIFIC DISCOVERY.

" As I do not iiitt'iid here doscrihinj^ the instninuMit in detivil, I
will only say that it consists es.<;i'ntially of a rcctanj^iihir brass box,
havings the 'society screw' at the top, to attach it to any micro-
scope tnbc, and at the bottom, to rc'ccive any objective ; and so
constrncted that it can l)e placed in any position with regard to the
li;rht. A brass draw, moved by screw and milled head, slides into
the box, and carries a relleetor of silv«u", also movable on its own
axis by means of small milled heads: the forward edp^e of the
reflector is cnrved, and it is concave, havini^ a focns of about six
inches. By means of the screw, the ourvccl edge of this i-eUector
can, when adjusted at an an<^le near forty-live degrees, be pushed
more or less over the opening at the back of the objective. Oppo-
site to the relleetor, and attaehe(l to one side of the box, is a re-
volving circle of iliaphragms, of great use in regulating the; light,
so as to exclude all fog or glare; the ajiertures vary from three-
twentieths to one-twentieth (jf an inch.

" As the ' illuminator' is already in the hands of many, I append
a few simple directions as to its use. The objective must be
adjusted for an uncovered object, though 1 find few are rightly
marked. An ordinary i)aper-covered slide, witii bits of gold l(>af
on it, answers athnirabiy as an ol)ject to adjust the light. The
illuminator being screwed on to the tube, and the circle of dia-
l)lnagms jdaccd facing the light (1 find the ordinary coal-oil lamp
Avith fiat fiame to answer admirably, the fiat side being toward the
refieetor), turn the icllector at an angle of al)ont forty-five degrees,
and allow the liglit to enter the largest aperture of the diaphragm.
By means of the screw, push the reflector forward nearly as far as
it will go. Turn the; reflector on the axis of the tube and on its own
axis, mitil the liglit, which may be placed ten or twelve inches to
the left of the microscope, and directly opposite the circle of dia-
phragms, is reflected down on the paper-covered slide, the tul)e
of the microscope i>eing racked up to about the position it will
occujjy when the objective is screwtid on and in focus. The light
thus reflected down should appoar just at the curved edge of the
reflector, in the axis of the tube, when looking through the tube,
the eye-piece being removed. Now screw on the objective, and,
before replacing the eye-piece, bring it into focus. The field will
appear brilliantly illuminated, as in using a lens with a Liebcrkuhn ;
if not, a slight movement of the reflector, or diaphragm, or light,
will quickly accomplish this. Put in the eye-piece and adjust for
focus; if the field is not clearly illuminated, say with one-fifth-incli
objective, a lijtle fingering of the reflector, or diaphragm, will
suffice to effect this. The screw which moves the draw and
reflector may now be withdrawn, uncovering all but about a quar-
ter or one-half of one side of the posterior lens of the objective ;
and, if care has been talcen to properly adjust the diapliragm and
reflector, a most brilliantly illuminated field, free from all fog and
glare, will reveal objects with a beauty and clearness inconceiv-
able by those who have never used high powers of the microscope
upon opaque oljjects. The most common objects appear with new
and hitherto unexpected beauty, brilliant not only with their own
proper colors, but reflecting iridescent tints from their membranes.

NATURAL PHILOSOPHY. 149

The diatoms are especially beautiful; and no one can view, with-
out a sense of profound reverence and unspeakable emotion, the
elegant structure of Ai-achnoidiscus and Heliopelta ; of Surirella
aud Pinnularia.

" On thus accomplishing the illumination of opaque objects under
the highest powers of the microscope, a powerful aid to investiga*-
tion is furnished, which, I doubt not, will be rightly appreciated.

" Au inexperienced microscopist may find some difficulty at first,
but a few trials will ensure success ; and, when properly used, there
is no want of light with the one-twelfth or even one-sixteenth
with the B or C eye-piece."

Mr. Charles Stodder exhibited before the Massachusetts Insti-
tute of Technology, in December, 18G6, a new illuminator of
opaque microscopic oly'ects under higli powers, the objective be-
ing its own condenser, — the invention of Mr. Tolles.

The principal difficulty met with in passing a beam of light
down through the objective of a microscoj^e, and thus condensing
a strong light upon an opaque object is, in the case of high pow-
ers especially, the reflection back of a considerable portion by the
lenses of tlie objective. This causes fog and obscuration of the
image, though the object be well illuminated. This reflection
takes place principally at the interior front surface of the front
system.

To obviate this difficulty, a small rectangular prism, immedi-
ately above the front- system, is so far inti'oduced into the side of
the objective mounting as to slightly encroach upon the extreme
margin of the upper surface of the coml)ination. When parallel
rays are reflected by this prism down through the marginal parts
of the front covered by it, they will have their focus much beyond
the place of the object. As a medium case, their distance of con-
vergence would be ten times the focal distance of the objective ;
consequently, a much greater poition of the whole light incident
upon the front system would be transmitted, and whatever amount
experienced reflection would be dissijiated by travelling back
through the objective in a path widely diiferent from that of the
visual pencil.

Mr. Stodder also exhibited a small telescope, of seven-tenths
of an inch aperture, and magnifying thirteen diameters, equal to
any instrument of two-inch aperture and three or four feet long,
with which he had been able to compare it. With this instrument,
which can be carried in the waistcoat pocket, he had been able to
distinguish the satellites of Jupiter, and similar astronomic ob-
jects. This was also made by Mr. Tolles ; and, if his present
plans succeed, the cost of telescopes of large size will be dimin-
ished one-half by the great reduction in the size of the lenses.

FOUCAULT'S SHEATHED OBJECTIVES FOR THE TELESCOPE,

The concentration of the luminous rays of liglit at the focus of

the telescope, when the sun is the object to be observed, renders

observations very difficult and sometimes even dangerous. M.

Leon Foucault has conceived the idea of utilizing the property

13*

150 ANNUAL OP SCIENTIFIC DISCOVERT.

wliich pertain niotals possess of arrestinij the calorific rays, Avhile
they allow the hiiiiinous rays to pass through. Silver, when de-
posited by a partieiilar chiMiiieal j)r()cess in very thin laAcrs, ])os-
sesses tliis proi)erty in a hii^h desjree. M. Foueanlt has slieathed
the objective of a telescope with a layer of this metal, and there is
produced at the focus of the instrument an image perfectly clear
and ai::reeal)le to the eye. It exactly resembles one which a
violet-colored glass would produce.

This discovery of M. Foucault has Ijeen pronounced by M. Le
Verri(!r to be of the highest possible imi)()rtance. M. Foucault's
experiment was made upon a telescope with a very small oi)jec-
tive. Since then, further experiments have been made on one of
nine inches, Avliieh were <iuite satisfactcny. The solar i"a3's re-
fracted by the objective sheathed with llu; metal liave a very pecu-
liar I)lui>h tint, which made M. Woltf imagine that a considerable
proportion of the calorilie rays might possii)ly have Ijecm elimi-
nated. The I'ays were examined with a spectroscope, and were
found to be dcjjrived of their extra redness, and inclined to be of
a very deep blue color. Clearly, the calorilie rays had been
sto])pi'd in their passage. Theory thus aflbrded the most brilliant
conlirmation t)f experience.

A large objective at the Observatory of Paris, which was in
process of construction, an'ordcd an excellent op])ortunity for ex-
l)eriment. 1'he exterior surlace of the glass was duly silvered,
and, on turning towards the sun, the image was presented devoid
almost entirely of its heat. The layer of silver in no way interfered
with the optical properties of the glass. All the numerous details
which the most experienced observers have detected in sun-spots
were at once visible. "The entire surface of the sun appeared
covered with an irregular stippling, the constituents of which
were of dilVerent sizes, and grouped in constellations of vai'ious
forms." "In pro])ortion," says M. Le Verrier, " as we see the
image better, all idea of a regular structure vanishes; nor is
there any indication of such a one as would result from the ag-
glomeration of identical elements placed in juxtaposition or dove-
tailed with each other. At some moments, the clearness is such
as to promise the analysis of the shaded portions, and make us
long to have recourse to more and more powerful instruments."
M. Fhimmarion, however, admits that the medium does throw
some kind of veil over the object investigated. — Header.

TEMPERATURE AT GREAT ELEVATIONS.

Mr. Glaisher has given, in a lecture at the Royal Institution, a
resume of his seientilie ex})eriments in balloons. Tables, record-
ing the decline of temperature with elevation, show that when the
sky was clear, a more rapid decline took place than when the sky
was cloudy. Under a clear sky, a fall of 1° takes place within 100
feet of the earth ; but at heights exceeding 25,000 feet, it is neces-
sary to pass through 1,000 feet of vertical height to obtain a fall
of 1° in temiierature. At extreme elevations, in both states of the
sky, the air became very dry, but, as far as his experiments went,

NATURAL PHILOSOPHY. 151

was never quite free from water. From ascents made bcfoi-e and
after sunset, Mr. Glai.sher concludes that the laws which hold
good by day do not hold good by night ; indeed, it seemed prob-
able that at night, for some little distance, the temperature may
increase with elevation instead of decreasing. From experiments
made on solar radiation with a blackened bulb thermometer, and
with Herschel's actinometer, it was inferred that the heat-rays
from the sun pass through space without loss, and become effect-
ive in proportion to the density or the amount of water present in
the atmosphere through which they pass. If this be so, the pro-
portion of heat received at Mercury, Venus, Jupiter, and Saturn,
may be the same as that received at the earth, if the constituents
of their atmospheres be the same as that of the earth, and greater
if the amount of aqueous vapor be gi-eater ; so that the effective
solar heat at Jupiter and Saturn may be greater than at either the
inferior planets. Mercury or Venus, notwithstanding their far
greater distances from the snn. This conclusion is most impor-
tant, as corroborating Professor Tyndall's experiments on aqueous
vapor. Experiments on the wind showed that the velocity of the
air at the earth's surface was very much less than at a high eleva-
tion. A comparison of the temperature of the dew point, as
shown by different instruments, gave results proving that the tem-
perature of the dew point, as found by the use of the dry and wet
bulb thermometers, and Daniell's hygrometer, is worthy of full
confidence as far as the experiments went. — Reader.

THE EFFECT OF SUNSHINE ON FIRE.

At the meeting of the Scientific Association at Buffalo, Prof.
Horsford, of Cambridge, read a very interesting paper on the above
subject.

He commenced by alluding to the popular notion that sunshine
deadens fires ; mentioning that the fii-es in grates, in rooms havino"
southern exposures, burn briskly in the early part of the day,
slacken before noon, and revive again before sunset. Stoves and
ranges, that bake well in the autumn, winter, and spring, fulfil
their oiRce but indifferently in the height of summer. Some fur-
naces, in which iron is generally smelted without difficulty, can-
not, in very hot terms, be brought to a working heat. While the
popular mind asci'ibes these effects to some agency of the sun,
scientific men are disposed to regard the effects as rather apjjarent
thaa real.

The first recorded research bearing upon the subject was made
as long ago as 1825, by Dr. Thomas McKeever, who found, as he
conceived, the popular impression sustained. In his experiments,
a given weight of wax taper was consumed quicker in the dark
than when exposed to the sun. A given length of candle required
less time for combustion in the dark than in sunshine. A given
weiglit burned quicker in a painted lantern than in an uncoated
lantern, both alike exposed to the sun.

These experiments did not find acceptance with Gmelin, and
did not appear in the original "Handbook of Chemistry," doubt-

152 ANNUAL OF SCIENTIFIC DISCOVERT.

less from a conviction that some error must have occurred either
in the metliod or record of observation. Nevertheless, Dr. Mc-
Keever's expei'iments appear as additions in the Cavendish Soci-
ety's translation of the Ilandbook. The summary of his results
may be stated thus : It required eleven minutes to burn in the
sunshine the same weight of candle that burned in the dark in ten
minutes.

Similar experiments were made at a later period by Dr. Morvill
Wyman of Cambridge, and reported to the American Academy
of Arts and Sciences. Ths result at which he aiTived was exactly
the reverse of that reached by Dr. McKeever. He burned two
sperm candles, each alternately for half an hour in the sunshine
and darkness, and found the candle, during its exposure to sun-
shine, burned more rapidly than when in the dark.

In 1856, the subject was taken up by Prof. Joseph Le Conte of
Columbia, S. C. He concentrated, witli the aid of a rellector and
burning glass, the sun's rays upon the ilame only of a wax
(sperm) candle in a large, dark room. At the same time another
candle was burning in the same room, under identical circum-
stances, except that tiie flame was not exposed to the sun's rays.
The result showed that tlie effect of the sun's rays, thougli greatly
exaggerated by concentration, when confined to the flame, did
not appreciably increase the consumption of tallow.

Here, then, we have, apparently, all possible results of experi-
ment, to wit: Sunshine diminishing the rate of combustion, as
observed by Dr. McKeever ; augmenting the rate, as observed l)y
Dr. Wyman, and producing upon it no effect whatever, as shown
by Prof. Le Conte.

Dr. McKeever ascribed the retai'dation to some peculiar effect,
as of interference,of the solar rays upon flame.

Dr. AVyman infeiTcd that the sunsliine, by warming the tallow
of the candle exposed to it, facilitated its melting, and by so much
spared, for destructive distillation and combustion, the heat of the
flame, which would have otherwise, in larger measure, gone to
liquefy the tallow.

Le Conte conclusively showed that, when the column of wax or
tallow is sheltered, and the sunshine directed solely on the flame,
the effect on the consumption of the tallow is too small to be
recognized.

The observations of the latter experimenters agree in throwing
doubt ujion the inferpretation Dr. McKeever gives of his own
experiments.

Prof. Horsford ascribes the source of error in Dr. McKeever's
investigation to the incidental greater flaring of the candle in the
dark. The experiments with the lantern he explained by the
well-known effect of dark paint in absorijing radiant heat, and
converting it into heat of conduction, by which the air in the
painted-glass lantern was more heated than in the lantern not
painted.

Prof. Horsford then gave an account of the diminished draft in'
the range flue of his dwelling-house during the recent hot terra,
which rendered it impossible to bake meats or bread in the oven

NATURAL PHILOSOPHY. 153

of his range. This continued from eleven o'clock to about three,
within which hours bread could not be baked. With the decline
of the sun in the afternoon, as in the early morning, tlie oven pei'-
formed its office better. The chimney was fifty-four feet high ;
the roof of the house was of dark slate, and it was all exjiosed to
heat before eleven ; some of it began to pass into shade about
three.

In the eflFect of this greater exposui'e to the sun during the
hours when the sun is brightest. Prof. Horsford found the ex-
planation of the observed phenomenon. The heated top and
sides of the bouse warmed the air in contact, giving rise to an
upmoving column from the top of the house and to an endless
shroud of air sweeping up the sides of the house. This ascend-
ing shroud draws the air from the cracks, doors, and windows of
the house, lessening the pressure of the air in the interior, and,
of course, diminishing the di-aft.

The following are his conclusions : —

1. That sunshine, falling on the flame only of a burning body,
does not affect its rate of combustion. 2. That, other things
being equal, neither light nor darkness exerts appi'eciable in-
fluence on the rate of combustion. 3. That, other things being
equal, of two samples of the same combustible, one burning in
sunshine will consume more rajoidly than one burning in dark-
ness. 4. That combustion during the winter is more vigorous
than in summer, becaixse a given volume of air contains more
oxygen, is denser and dryer. 5. That slight currents, by causing
a flame to flare and come in contact with more air in a given
time, cause more rapid combustion ; and, by presenting greater
surface from which radiant heat issues to warm the combustible
about to burned, increase the rate of combustion. 6. That the
diminished draft of chimneys in very hot weather, when the
general atmosphere is at rest, and the sunshine intense, is due to
upward currents on the outside of the house, arising from the
heated surfaces of the roof and walls, which currents draw out-
ward through cracks, and open doors and windows, the air from
the interior of the house, and so lessen the pressm-e within, and
overcome the draft of the chimney. 7. That the popular imjjres-
sion that intense sunshine lessens the draft of chimneys is founded
in fact. — Scientific American.

TRANSFORMATION OF MOTION INTO HEAT.

Mr. Rennie has demonstrated in the most satisfactoiy manner
that this ti'ansformation takes place, even in the case of fluids.
He boiled an egg in six minutes by merely placing it in a vessel
which contained about ten pounds of water, and which was made
to revolve two hundred and thirty-two times in a minute. In
this case, motion was the only possible source of heat ; and the
result Avas the more striking, as the friction of fluids is so very
much less than that of solids. — Intellectual Observer, May, 1866.

154 ANNUAL OF SCIENTIFIC DISCOVERT.

DURATION OF THE SUN'S HEAT.

Profr>s<5or Thomson assigns to the sun's heat, snpposinj]^ it to be
maintained by the ajjpulse of masses of matter, a limit of 300,000
years ; and to the period of coolinj^ of the earth, from universal
fusion to its actual state, 98,000,000 years. These are the lowest
estimates sanctioned by any mathematician.

DIFFERENTIAL RHEOMETER.

Tn a note, on the em]iloyment of a double-wire rheometer in
experiments on radiant heat, sent to the Academy of Sciences by
M. P. Desains, the author states that he employs a kind of differ-
ential apparatus essentially comjiosed of a sino^le source of heat,
of two ])iles, of a doul)le-wire rheometer, and finally of a rheo-
stat. The apjiaratus is so arran<^ed that the equilibrium, once
ol)tained, remains uniform however the heat from the source
varies ; but if the smallest variation takes place in one of the
radiations, the needle quits the zero point. M. Desains has ap-
plied this api)aratus to the examination of the absorption of heat
by transparent gases, and finds that it gives very delicate and
certain indications. — Scientific American.

CONDUCTING POWER OF MERCURY.

M. Gripon has presented a note to the Academy of Sciences on
the conducting power of mercury for heat. Experiments made
after Peclet's method showed that, if tlie conducting power of
silver equals 100, that of mercury equals 3.54. It stands, there-
fore, the last of the metals, and a little before marble and gas
coke. The author mentions that, in this case, the conducting
power for heat and for electricity are very difi'erent, the former
being 3.54, the latter 1.80. — Mechanics' Magazine.

A NEW PYROMETER.

Messrs. St. Claire Deville and Trooste have invented a pyrome-
ter capable of measuring a temperature reaching as high as 1530°
C. At this heat, the inventors state, co^Dper and silver are va-
porized, and feldspar perfectly fused.

IMPBOYEMENT OF THE HYPSOMETER.

The boiling points of fluids depend on the pressure of the air ;
the greater the altitude of any place above the ordinaiy level of
the earth's surface, the lower the boiling point of a given fluid,
because the less the barometric pressure in that place ; and hence
the height of any place may be found by means of the boiling
point of water in that place. With this object, a peculiar kind of
thei-mometer, termed a hypsometer, or, more con-ectly, a hypso-
thermometer, has been constructed. It is marked not with degi'ees
of temperature, but with barometric pressure corresponding to these

NATURAL PHILOSOPHY. 155

degrees, oi', better still, according to the latest improvements of
M. Abaddie, with the altitudes corresponding to the tempei-atures,
supposing them to be the boiling points of water. The hypso-
meter is, for several reasons, more suitable for the purposes of
travellers than the barometer: it is more easily carried, and less
easil)^ injured, and it requires, not an observation, but an experi-
ment which is made with greater facility, and is less subject to
error. — Intellectual Observer, October, 186G.

THERMO-ELECTRIC ELEMENTS OF GREAT MOTIVE POWER.

^ Stefan has examined a variety of mineral substances, with rela-
tion to their thermo-electric power at high temperatures. The
mineral to be examined was placed upon one end of a strip of
copper, Avhile the end of a copper wire rested upon the minei-al,
the whole being pressed together to insure contact. The wire and
copper strip were connected with a galvanometer of gi-eat resist-
ance, and the copper strip was then heated by a spirit lamp. In
examining the mutual relations of the minerals, a copper strip was
placed between them, wires attached to the free ends of the frag-
ments of mineral, and the whole pressed together by a wooden
press. The free end of the copper stinp was then heated, and the
heat conducted to the minerals. In the following enumeration of
the elements employed, the positive element is always placed first ;
and the number apjjended signifies how many of the elements give
an electro-motive force equal to DanieU's cell : —

1. Foliated copper pyrites — copper; 26.

2. Compact copper pyrites — copper; 9.

3. Pyrolusito — copper; 13.

4. Compact copper pyrites — foliated copper pyrites; 14.

5. Copper — crystallized cobalt pyrites; 26.

6. Granular cobalt pyrites — copper; 78.

7. Copper — iron pyrites; 15.7.

8. Compact copper pyrites — iron pyrites; 6.

9. Foliated copper pyrites — iron pyrites; 9.8.

10. Copper — erubeseite; 14.

11. Fine bleischweif — copper; 9.8.

12. Coarse bleischweif — copper; 9.

13. Galena in large crystals — copper; 9.8.

14. Bleischweif — erubeseite; 5.5.

The great influence of stnicture upon the thermo-electric rela-
tions is seen in Nos. 1, 2, and 4, and still more in 5 and 6. A mass
of cubical crystals of galena was at some points negative, at oth-
ers positive, to copper. The densest. No. 14, has the greatest
electro-motive force yet observed in thermo-electric series ; but
the substances employed are all bad conductors. The author con-
siders, and we think justly, the above results as of great import-
ance for the physics of the earth, and proposes to continue the sub-
ject. In a note to vStefan's paper, Poggendortt" calls attention to
an observation of Marliach, made in 1857, according to which,
crystals of iron pyrites (Fe. S2) and ofcobaltine (Co. S2 — Co. Aso),
which cannot be distinguished, either in crystalline form or in

156 ANNUAL OF SCIENTIFIC DISCOVERT.

composition, are divided, so far as their thermo-electric relations
arc concerned, into two ji;roiips. Calling tiie two forms of the
minerals a and b, Mar!)ach j^ives the following series, reckoning
from negative to positive : Iron jn'rites, a ; cobaltine, a; bismuth,
German silver, platinum, lead, copper, brass, silver, cadmium,
iron, antimony cobaltine, 6; iron pyrites, 6. — Pogg. Ann., April,
1865, as quoted in American Joicrnal of Science, September, 1805.

A NEW AND POWERFUL THERMO-ELECTRIC BATTERY.

In a communication to the Vienna Academy, dated March 16,
1865, S. Marcus di'.scril)t'd a nmv thermo-electric battery, which
possesses extraordinary interest, botli in a theoretical and practi-
cal point of view. The properties of the new battery are as
follows : —

1. The electro-motive force of one of the new elements is equal to
l-2oth of tiiat of a Bunsen's clement of zinc and carbon, and by
its internal resistance is equal to 0.4 of a meter of normal wii-e,

2. Six such elements are suJlieient to decomiJose acidulated water.

3. A battery of 125 elements evolved in 1 minute 25 cubic cen-
timetres of mixed oxygen and hydrogen, although decomposition
took place under disadvantageous circumstances, as the internal
resistance of the battery was much greater tlian that of the
voltameter in the circuit. 4. A jjlatinum wire of ^ millimeter in
thickn(!ss, introduced into the circuit, melted. 5. Thirty elements
develop in an electi-o-magnet a lilting power of 150 pounds. 6.
The current is generated by warming only one of the contact
sides of the elements, antl cooling the other, by means of water
of the ordinary temperature.

As positive metal in tliese batteries, Marcus employs an alloy
of 10 parts of co])per, 6 of zinc, and 6 of nickel. The addi-
tion of 1 part of cobalt increases the electro-motive force. For
the negative metal lie uses an alloy of 12 jiarts of antimony, 5
of zinc, and 1 of bismuth. The electro-motive force of the alloy is
increased Ijy repeated fusion. In place of these alloys, a partic-
idar kind of Germ.an silver, known as alpacca, may be used with
the same negati\ e metal ; or, as the positive metal, an alloy of 65
parts of copper and 31 of zinc, and, as the negative metal, an
alloy of 12 parts of antimony and 5 parts of zinc. The bars are
not soldered but screwed together. The mechanical arrangement
is such that only tlie positive metal is directly heated, the negative
metal being warmed by conduction; the former melts at about
1200° C, the latter at about 600° C.

An interesting fact in relation to the transformation of heat into
electricity in the thermo-electric battery, is, that the water wliieh
serves to cool one of the contact sides of each element, becomes
very slowly warmer so long as the circuit remains closed, but is
heated pretty rapidly when the circuit is open. The alloys em-
plo3-ed in this battery fulfil several conditions essential to the pro-
duction of powerful electrical currents by heat. These conditions
are, that the metals employed should be as far as possible from
each other in the thermo-electric series ; that they should permit

NATURAL PHILOSOPHY. 157

great differences of temperature, so as to avoid the necessity of
using ice ; that they should not be exi3ensive ; and that the insu-
lating material ^oukl resist a high temperature, and possess suf-
ficient solidity .uid elasticity. The thermo-electric battery in
question was constructed in reference to the use of a gas llame.
The single element consists of bars of unequal dimensions, the
positive bar being 7" long, 1'" broad, and h'" thick ; the negative,
6" long, 1'" broad, and &" thick. Marcus puts together 32
elements in such a manner that all the positive bars are on one
side, and all the negative bars on the other, and have thus the
form of a grating. The battery consists of two such gratings,
which are screwed together in tlie form of a roof, and strength-
ened together by an iron bar, mica being used as an insulator.
The under sides of the elements are cooled by a vessel of water.
The whole battery has a length of two feet, with a breadth of six
inches, and a height of six inches. Marcus has constructed a fur-
nace, which is calculated for a battery of 768 elements, which
would correspond to a Bunsen's battery of 30 pairs, and consume
240 lbs. of coal per day. The Vienna Academy, recognizing the
imijortance of the discovery, has voted to the inventor the sum of
2,500 guilders, the invention to be public projierty. Pogg. Ann.,
April, 1865; from " Amer. Journ. of Science" for, Sept. 1865,
the Editor of which appends the following note : —

" The importance of Marcus's invention, in a technical point of
view, can hardly be over-estimated, since it promises to fui-nish
the cheapest method of obtaining an intense light for light-houses
and public buildings ; and even holds out a prospect, perhaps not
remote, of applications in domestic economy.

"It must be remembered that the step taken by Marcus is, after
all, a first step in the right direction. Bunsen, E-. Becquerel, and
Stefan, have shown that there are thermo-electric combinations
of much higher electro-motive force than those employed by
Marcus, although the internal resistance is too great to permit of
their use in constructing large batteries. If the i^rogi'ess of
science should make us acquainted with metallic alloys, which,
when combined and arranged as thermo-electric elements, de-
velojj electro-motive force as high as one-tenth of that of a Bun-
sen cell, the thermo-electric battery will again become a new
instrument. Iji this connection, we suggest that the thermo-
electric relations of the highly crystalline alloy of iron, manganese
and carbon, known as ' spiegeleisen ' (that from the Franklinite
of New Jersey for examjile), deserve a careful studJ^ The i^os-
session of a galvanic battery in which coal is consumed in i^lace
of zinc and acids, can hardly fail to revive an interest in electro-
magnetic engines, like that of Page, even if only for cases in
which comparatively little jjower is required, since bur best steam
engines do not yield ten per cent, of the work which the con-
sumption of the coal is capable of doing."
14

158 ANNUAL OF SCIENTIFIC DISCOVERT.

WILDE'S MAGNETO-ELECTRIC MACHINE.

The principle is this : An armature wound round with insulated
wire is made to revolve rapidly in front of the poles of a larj^e
permanent magnet. The eurrents of eleetricity, thus induced in
the insulated wire, ai'C carried rounil a large electro-magnet, which
is thereby excited to a very iiigh degree. In front of tiiis electro-
magnet, a second covered armature is rotated ; and (lie electric
current thus generated is carried round a third electro-magnet.
It is from a rotating armature in front of this third magnet that
the electric current, ultimately used for heating or lighting ellects,
is produced. At each passage rouiul the electro-magnets, and
induction in the rotating armatures, the electric current becomes
magnitied to an extraordinary degree, until ultimately it is pow-
erful enough to melt iron bars in a minute or two, an<l to i)roduce
a light surpassing that of the sun itself. The machine is driven by
means of a steam engine, and, as almost the only current expense
is for motive power, it is not an improbable sujiposition that ere
long electric lights of the most intense description will be as
common in large factories and public buildings, as gas lights are
at the present time.

The great, advantages of this over the old system of magneto-
electric machine ai)pears to l)e that it is capable of amplifu;aLion to
any required power, by a mere enlargement of the size of the dif-
ferent parts. His largest machine weighs about three tons. If,
instead of using the electric current generated by it to produce
dynamic elfects, we pass it round a still larger electro-magnet,
we should at once produce a vastly greater development of force.
The only limit which we see to this multiplication of power is the
excessive heat which would be developed in the rotating arma-
tures. One very interesting i)ractical ai)plication of this brilliant
and economical light is to photography, for which it is more con-
venient than the sun. By its aid more than two hundred nega-
tives can be exposed in a day, to secure gelatine reliefs. This is
the lirst practical application of the electric light to the commer-
cial working of photography, its constancy rendering it here more
valuable than an uncertain sunlight. — Quarterly Journal of Sci-
ence, 1866.

ELECTRICITY AS A MOTIVE FORCE.

Mr. !Moses G. Farmer, who has paid great attention to the ori-
gin and measm*e of electro-motive force, and the resistance which
the current encounters in its passage through metallic wires and
plates, has pointed out the numerical rules for computing the
mechanical power derivable from a given consumption of metal
in the battery, as compared with that furnished by an equal
weight of coal ; from which it aj^pears that, until some much
cheaper mode of generating electricity shall be discovered, this
force cannot compete, as a motor, on a large scale, with the force
derived from ordinary comljustion.

NATURAL PHILOSOPHY. 159

PNEUMATO-ELECTRIC ORGAN.

Electricity has been vei-y ingeniously and effectively applied to
fonu a connection between the keys of an organ and the valves
which permit air to pass to the pipes. Comjilicated mechanism is
thus got rid of, an extremely simple arrangement, whatever the
distance between the keys and the pii^es, being substituted.
According to the "Scientilic Review," when any key is depressed by
the finger, a small commutator under it completes communication
with a galvanic battery, by di^iping its lower ends into minute
cups of mercury. Electricity then passes along a wire to a small
electro-magnet, that immediately becomes excited, and, attract-
ing a keeper, opens a valve, allowing air to pass into the organ-
pipe, which sounds at once, and continues to do so as long as tlie
finger presses down the key. It is clear that, however powerful
the organ, or distant the pipes, the fingers are not in the slightest
degree disti'essed in playing. The battery used is simple, inex-
pensive, and permanent in its action. It consists of glass vessels,
arranged on the upper surface of the bellows, and each containing
a solution of sulphate of mercuiy ; into the latter plunges a plate
of zinc, which is placed between two plates of gas retort graphite,
when the bellows is raised by the action of blowing. No effect,
therefore, is produced, except when required, which prevents
waste of battery power. The zinc requires to be rej^laced, and
the mercury, thrown down by the zinc which is dissolved, to be
re-formed into sulphate, about every six months.

SUN-SPOTS VS. MAGNETIC VARIATION.

Father Secchi has just completed the reduction of the observa-
tions made during the years 1859 to 1865, inclusive, of the amount
of magnetic variation, on the one hand, and of the number of
groups of spots visible on the sun, on the other. The i-esults are
very interesting, as showing the intimate relation between the
two phenomena, — a minimum of spots invariably corresi^onding
to a minimum of magnetic variation.

DEVIATION OF THE COMPASS.

INIr. E. S. Ritchie read a paper before the Massachusetts Institute
of Technology, in February, 1865, on the deviation of the compass,
caused by the iron used in the construction of vessels, and the best
mode to correct it. The causes of the disturbance are : 1. The
presence of soft iron, which attracts equally each pole of the
needle, with a force nearly constant in all positions of the ship on
the earth's surface, and for all time. 2. The magnetism induced
by the earth in iron placed in or near a vertical position, causing
in the Northern hemisphere the lower end to become a North
pole, while in the opposite hemisphere it becomes a South pole.
3. Magnetism induced in the iron by rolling, hammering, etc.,
during the building of the ship : this is more or less permanent
according to the hardness and quality of the iron ; and, among

100 ANNUAL OF SCIENTIFIC DISCOVERT.

Other chanfrcs, is liable to be increased by the often-ropeatcd
strokes of iho waves.

The method usually adopted to coiTect these deviations is, by
so plaeing^ bar-uiairnets as to eoniiteract the uiaijnctism of the sliip.
But, as every vessel has its own luajjnetie peculiarities, — as in
some vessels the error is coni))aratively small, or nearly constant
for a considerable time, while in others the amount of deviation
chanj^cs <>^reatly and suddt-uly, — the bar-ma irnets, remaining
constant in foree, cannot ije relied on to correct the deviation.
The prevalent idea among shipmasters, that the deviation was
necessarily of the same amount, and opposite in direction on op-
posite conrsi'S of tiie vessel, is erroneous, and the placing of the
local magnets for correction in consecjuence of no a^'ail.

It is of great importance that masters of vessels should make a
table of errors for at least sixteen points of the compass, with a
proper allowance therefor, and frequently verify or correct this
table of errors, and test the course daily by means of the azimuth
comjiass. If this precaution were used by all masters of vessels,
not only would the list of disasters be very greatly reduced, but
the length and expense of voj'ages, and the premium of insur-
ance, would be diminished.

ACTION OF SULPHUE IN A NEW FORil OF VOLTAIC BATTERY.

M. Zyiatteucci communicated to the French Academy of Sci-
ences a memoir on the above subject, the chief jjoints of interest
in which are as follows : —

The autlior recently had his attention directed to the action of
sulphur in a new form of battery invented by M. Blanc Filipo.
This battery has for its positive electrode a plate of zinc plunged in
a solution of conmion salt, and for the negative metal a plate of lead
covered by electrolysis with a very thin layer of copper; enough
flowers of sulphur were then mixed with the liquid in the cell to
form a thin paste. The needle of a galvanometer, Avhich had
been included in the circuit, immediately began to move upwards :
after some hours it i-eached nearly the same deflection as would be
shown by employing a Daniell's cell of equal size, and remained
at the same degree for four or five days, the circuit being closed
during the whole of this time. At the end of this period, the
layer of copper was found to have changed into sulphide of cop-
per, and the liquid had become highly charged with sulphide of
sodium, mixed with traces of sulphide of copper. The only dis-
advantage at present connected with this battery appeared to be,
that, during its action, a small quantity of sulphuretted hydrogen
was liberated : notwithstanding this, it is likely to be a most valu-
able instrument for telegraphic purposes.

M. Matteucci found that plates of platinum, iron, copper, silver,
or any other electro-negative metal, when covered with a layer of
copper, which is absolutely necessary, gave a constant current,
similar to the coated plate of lead. When, instead of copper, the
plates were coated with silver or lead, the same action took place,
the metal being changed into its sulphide. With copper, how-
ever, the action was most prompt, intense, and i^ermanent.

NATURAL PHILOSOPHY. 161

The author then shows, by exiDeriments, that to ohtain the
proijer etiect of sulphur in the battery, it is necessary that the
suli)hur should be mixed with a solution of common salt, or with
any other salt of soda, or j^robably with any alkaline base ; it is
also essential that the sulphur should come in contact with the
copper. Experiments showed that this action of sulphur was
subject to the fundamental law of the battery ; for, taking into
account the traces of sulphui'etted hydrogen which are disen-
gaged, and the very small quantity of sulphur which is combined
with the copper, the conclusion was arrived at that the zinc dis-
solved, and the suljihur combined with the sodium, as protosul-
phide, in the exact ratio of their equivalents. Summing up his
results, M. Matteucci arrives at the following conclusions : —

1. That finely-divided sulphur, placed in contact with the elec-
tro-negative metal of a battery composed of zinc, copper, and
solution of common salt, notably augments the electro-motive
force, the constancy and the duration of the battery. It is thus
hoped, that, by the employment of sulphur, a voltaic combination
may be obtained having many advantages over those batteries
which are ordinarily used in industry.

2. The suljihur, though insoluble, and uncombined, enters into
combination with the sodium set free by the electric current.

The action exercised by the small quantity of sulphide of cop-
per which is formed still remains to be exijlained. This action
appeal's to be essential to the battery. Instead, however, of offer-
ing any theory on this sul)ject, M. Matteucci has undertaken fur-
ther experiments to elucidate this point.

INDUCTION COILS.

At a recent meeting of the Royal Scottish Society of Arts, held
in their hall, George Street, Edinburgh, Sheriff Hallard presiding.
Dr. Ferguson read a paper on a new method of constructing
induction coils, an abstract of which will be interesting to our
readers. One peculiarity of the method consists in coiling the
secondary wire round the jjrimary coil, in lengths proportionate
to the power of the primary coil at the point where the wire is
coiled, there being least at the ends and most in the middle. By
this construction, the length of the spark given by the induction
coil is not purchased, as it generally is, at the expense of its vol-
ume. Another peculiarity is, that the wire is wound in two parts,
separated by a diaphx-agm, and the poles stand at the same dis-
tance from the primary coil. Both poles are thus alike a power.
In the usual arrangement, one pole is weak and the other strong.
A coil constructed on this method by Mr. Hart, of College Street,
was exhibited, which gave readily dense sparks of eight inches in
length. The insulation of the coil has been so applied and pro-
tected as to secure the permanent power of the coil. The length
of the wire on the secondary bobbin is nearly seven miles.
Another paper on a new cun^ent interrupter for the induction coil,
also by Dr. Ferguson, was read. In this contrivance, a spiral of
copper wire, free to oscillate in the middle, is fixed at its end to
14*

162 ANNTAL OF SCreXTIFIC DISCOVERT.

a rod of iron as a case. A wire, soldered to the coil, comes out
at riglit anij^lcs IVoin it; and, bcinij l)ont down at tlie end, dips
into a cup contaiiiirig mercury. The batter}' connection is so
arranged, that when the dipping wire is in the cup the galvanic
circuit is closed. On th(^ closing of the circuit, the dippi'r is
drawn out of the cup, and tiic circuit is thereby broken ; and tiie
coil, under the action of its electricity, returns to its former j)osi-
tion. The dipper is thus alternately lifted up, and plunged into
the cup, and a rapid series of interruptions is made. This inter-
ruption admits of a simjile and perlVnit system of regulation, so
that it can l^e made to move at any speed. It does away with
the armature and spring of ordinary self-acting brakes, is quite
continuous;, and introduces almost no resistance into the primary
circuit. Tiie interruption was used with the coil, and several
experiments illustrative of the merits of botli were performed.

ELECTRIC SIGNALS ON RAn.ROADS.

Before the Institution of Civil Engineers, an interesting paper
was read l)y W. H. Treece, Associate, "On tiie best means of
conununieating between the passengers, guards, and di'ivers of
trains in motion." Mr. Preece exi)lainod tliat tlie essentia! ]mn-
ciple of the system he had introduced in the trains of the South
Western, the Midland, and the tlreat Northern, was the exten-
sion of a single isolated wire throughout tlie wiiol*; train, wliich
was maintained in a state of electrical equilil)rium by having the
similar poles of every battery in each van and engine attached to
it, while tlieir opposite poles were connected witli the earth, so
that when this Cijuilibrium was disturljed by placing the wire to
earth tlu'ougli the framework, wlieels, and rails in any carriage
or van, the current from each battery acted upon the l)e]l in its
own van, and upon a signal on the engine. Its i^eculiarity con-
sisted in tliis, that the commutators in each compartment of every
carriage Avere protected from the miscliievous and idle I)y being
covered with glass, which had been found experimentally to be
tlie best material for the purpose, as any opaque substance excited
inquisitiveuess and interference.

MUTUAL ACTION OF ELEMENTS OF ELECTRIC CURRENTS.

The law of Ampere — that commonly recognized as expressing
the action of two independent elements (or infinitesimal portions
of electric currents) — was based on a certain assumption, and on
four cases of equilibrium experimentally determined. The as-
sumption of Ampere was, that the direction of the action was
constant, independent of the X'clative direction of the elements,
and that the quantity or intensity of the action varied with the
direction of the elements. The new assumption is the reverse of
this, to w-it, that the intensity of the resultant is independent of
the direction of the elements ; but that the direction of tlie result-
ant varies with that of the elements. The latter view moi-e closley

NATURAL PHILOSOPHY. 163

corresponds to the doctrine, now generally admitted as estab-
lished, of the correlation of the physical forces. It is also, in
form, more closely analogous to the law expressive of the mutual
action of material masses under the influence of gravity.

In the case of gravity, the action was proportioned dii-ectly to
_ the product of the masses, and inversely to the square of their
'distance. _ In the case of electrical currents, the direction of the
elements is to be taken into consideration ; and the resulting force
may be expressed as the product of the quotients of each element
(considered both as to strength of current and length and direc-
tion of the element), divided by their distance (also considered
both as to length and direction). The consideration of direction
involves the application of the newly-developed principles of the
mathematical science of quarternions.

The law above mentioned being assumed, all of the other ordi-
nary special laws of electrical action flow readily and necessarily
therefrom ; as, for example, the mutual action of closed circuits,
and the action of magnets considered as solenoids. — E. B.
Elliot, in Froc. Am. Ass'n,for Adv. of Science, 1866.

INSTRUMENT FOK SHOWING MINUTE CHANGES OP MAGNETIC

DECLINATION.

Dr. Joule described, before the Literaiy and Philosophical Soci-
ety, an instrument he had constructed for rapidly showing minute
changes of magnetic declination. A column of small magnetic
needles is suspended by a filament of silk. Attached to the lower
end of the column is a glass lever with a hook at its end. A
second fine bent glass lever is suspended by another filament of
silk ; its shorter arm l^eing connected with the first lever by means
of the small hook. The whole is enclosed in a stout copper box.
Light is admitted into the box through a lens, cemented into an
orifice immediately under the object-glass of a microscope, placed
over the free extremity of the bent lever. The microscope mag-
nifies about three hundred linear, and has a micrometer in its eye-
piece, with divisions corresponding to one two-thousandth of an inch.
One division corresponds to a deflection of the needle of four and
one-half minutes, and, as a tenth of a division can be vei-y readily
observed, the instrument measures deflections to within half a
second. So rapid is the action, that, on aj^plying a small mag-
netic force, the index takes up its new position steadily in two
seconds of time. Besides being a damper to the motion of the
needle, the copper box, by its conducting power, equalizes the
temperature rapidly, so that the indications are not to any consid-
erable extent disturbed by currents of air. The success of the
present instrument encourages the hope that very much greater
delicacy may yet be obtained. Dr. Joule said that he had ob-
served an extensive magnetic disturbance the preceding evening,
the index being driven entirely out of the field of view.

IGi ANNUAL OF SCIENTIFIC DISCOVERT.

. ELECTRICAL FLYING FISH.

The experiment of the "flying fish" has excited attention in
Paris. M. rAl)l)e L:il)onle and M. Sallei-on have both written to
•' Les Mondes " on the subji.'ct. Each suggests making use of the
conductor of an electrical machine in place of a charged Leyden
jar. M. TAblie Laborde says, in the following manner the exper-
iment can be easily made by any who possess an ordinary electri-
cal machine : A piece of gold leaf or silvered paper is cut into the
shape of a kite ; this is then i)laced on the conductor of a machine,
and a ball connected with tiie rubber slowly approached to the
blunt end of the leaf. Soon the leaf rises and springs from the
conductor, remaining iiovering in the air between it and the ball.
The finger can be substituted for the ball, and the leaf led even ver-
tically round the conductor with a considerable intervening space.
The tlistance of tlie leaf from the ruljlier almost entirely depends
upon the size of the blunt angle, — the more obtuse this angle, the
nearer the leaf approaches to the rubber. The explanation given
by M. TAbbe Laborde is, that the jioint presented to the electrified
body, receiving electricity of the same name, is repelled, which
it would be altogether, were it not that it i)arts with its elec-
tricit}' by the other point, can be again attracted to the electrified
bo(h', and is again repelled. Thus repulsion takes place in ap-
proaching the conductor, because it receives more than it loses ;
but immediately attraction ensues, because now it loses more than
it receives. The equililjrium between these two opposing forces
enables the gold leaf to maintain itself in the air at a distance from
both solid bodies.

ELECTRICITY IN DEEP-SEA SOUNDING.

In deep-sea sounding, the greatest difficulty is felt, even by ex-
perienced persons, in ascertaining the precise moment at which
the lead of the sounding-line touches the bottom, — a matter on
■which the whole value of the sounding dejiends. An apparatus
invented in France, at Lyons, removes, it is said, evei*y difliculty
on the point. The sounding-line contains within it, along its whole
length, two insulated conducting wii'es, the uiiper ends of which
ai'e connected i*espectively with the poles of a galvanic battery in
the ship. The lead is in two paits, the lower one of which is jjartly
inserted into the upper, and is capable of a limited vertical motion
within that of the other, so that, when left to hang freely, a small
empty space is left within the upper portion by the spontaneous
descent for a short distance of the lower portion. To the upj^er
end of the lower portion, and within the ujjper jjortion, is attached
a commutator, which is contained in an insulating and water-proof
sheath, and which, when the lower portion of the weight is raised
by contact with the ground, comes in contact with the ends of the
conducting wires, so as to complete the circuit. Instantly, by
means of the ordinarj- electro-magnetic apj^aratus, a bell is rung
on board the ship to attract the attention of the sounder, and a
ratchet is thrown into action, which "Urrests the unwinding of the

NATURAL PHILOSOPHY. 165

line from the drum on which it is coiled, so that no more can run
out. This appai-atus is applical)le also when the lead is kejjt hano--
inof down at a certain distance from the ship, for the purpose of
indicating^the presence of rocks or reefs, or that the water has be-
come shallow, so as to give timely notice of approaching dano-er.
— Scientific American.

LIGHTING OF THE CAPITOL DOME.

The efforts of Mr. Samuel Gardiner, of New York, in this en-
terprise have been crowned with triumpiiant success. For two
years and a half tlie arrangements have Ijeen quietl}' pei-fectino-,
and on the evening of the 2od of January, 18(36, the dome was
illuminated from three circles of burners, invisible from the floor,
and containing 1100 jets, from 6 to 12 inches apart, bringing out
in splendid relief the picture executed by Mr. Brumidi on the
ceiling of the inner dome, at a height of 180 feet from the floor of
the rotunda.

The means for operating the battery, turning on and off the
gas, and lighting each tier of burners, are brought within a space
of two feet square in a passage-way within a few feet of the
floor of the rotunda, and consists of a silvei'-mounted dial-plate
with keys, eleven in number, one in the centre, by which the
jDrimary connection is made, and the required amount of bat-
tery brought into oj^eration, the others being for the gas and
lighting connections of the respective tiers. Tlaese tiers, it may
be here mentioned, are three in number at present; the first,
containing 300 burners, at the lower cornice, 45 feet from the
floor ; the second, of 325 burners, at a cornice 80 feet from the
floor; the third tier, 425 burners, 165 feet from the floor, sur-
rounding the balustrade, and near the margin of the picture on
the ceiling.

The flrst and second series of burners are entirely inaceessilile,
all are invisible from any part of the floor, and every possible
manipulation is executed at the dial-plate on the floor by the ex-
ertion of a few ounces pressure on tlie ajipropriate key, the gas
stop-cock to each tier being operated by an electro-magnetic en-
gine in its vicinity, which receives its imjiulse from the battery,
the central heart of the concei'n, communicating light, heat, and
force, under the guidance of the brain which directs the current at
will through the five miles of wire. This lieart of the apparatus,
whose impulses are thus directed, is housed in and fully occupies
an elliptical room 45 by 36 feet, and consists of 200 jars, arranged
on tables in concentric series, eacli jar being 13 inches in diame-
ter, 14 inches deep, and so arranged as to he thrown on or oft" in
sections of 20, by the key on the before-named dial-plate in a
passage remote from the battery. A vernier on the dial-plate, in
connection witli a pointer on the central key, indicates the extent
of the battery which is brouglit into ojjeration by the revolution of
the key. Openings in the dial expose dark and light segments
of the wheels on the gas keys, so as to indicate the shut or open
positions of the gas stop-cocks at the tiers 45, 80, 165, and the

166 ANXTAL OF SCIENTIFIC DISCOVERT.

cluster 2G4 feet above. Owing to the heij^ht, a gas regulator is
proviilod at the stop-cock of each tier, which equalizes tlie flow.
Ko. 10 copper wires are used throughout; and, after being
wrapped with linen, are inclosed in India-rubber tubing, and
incased, or otherwise secretly laid, passagt!s in the walls being
drilled therefor through a thickness of from 3 to 20 feet. The
return circuit is made through the gas })ipes, saving a duplication
of the nine thousand 3ards of wire. The burners used have an
indestructil)le lava ti|), which acts as an insulator, and each is
provided with an insulated coil of jdatinum wire on one side of
tlie orilices, so as not to interfere with the free exit of the gas,
while exposing one side of the jet to the action of the red-hot
metal when the electric connection is made.

The experiments liave covered a period of nearly ten years, and
six patents cover the main features of the invention. The ex-
periments, on so grand a scale as the Capitol dome, with 1100
burners, at such distance and elevation, settle the question of
success; and the invention will come into general use for lighting
theatres, concert and public halls, and eventually, by large central
batteries, will ramify over city districts, to aiibrd to residents,
merchants, and manufacturers, a connection for the purpose of
iustautaucous illumination to any extent desired. — Sciait. Am.

PROTECTION AGAINST LIGHTNING.

The present summer, so far, has been remarkable for the num-
ber of accidents from discharges of electricity. We believe there
has been no storm this season, accompanied with lightning, which
has not resulted in damage to person or proj^^rty. In view of
tliese facts, the importance of providing adequate protection to
buildings and ships, from lightning, can hardly be over-estimated.
The failure of lightning-rods, in some instances, to protect the
structure to which they were attached, has had the effect to im-
pair confidence in such means of protection ; but it can be clearly
demonstrated that, when made on scientific principles, honestly
consti'ucted, and properly applied, they are the only means which
can be relied upon for protection, and that they are deserving of
entire confidence.

The electric fluid does not always descend in a vertical path,
nor in a coui'se approaching that direction. Many instances are
on record where the bolt travelled horizontally, and much dam-
age has occurred from "earth strokes" or ascending discharges.
These facts have not alwa\"s been recognized by constructors of
lightning-rods, their idea being that a building was sufliciently
insured against lightning by having the rods jiroject above the
highest poilion of the building, leaving all the other parts unpro-
tected. Experience has added its evidence to the instructions of
science in demonstrating the unreliability of such protectors.

From Lyon's " Treatise on Lightning-Conductors," we copy the
following requisites of a good rod : —

"1. The conductor should be made of good conducting sub-
stance.

NATURAL PHILOSOPHY. 167

«*2. It should have great electrical capacities; a square i-od
requires less metal than a round rod.

"3. It should be perfectly continuous, i. e., it should have no
breaks in the connections, — no links or hooks, but a perfect
metallic union of every part.

"4. It should be insulated from the building to be protected,
except from such masses of metal as are likely to offer other lines
of discharge.

"5. It should have numerous lateral points ; one in six or seven
feet will answer. The more numerous these points are, the
gi'cater the conducting power of the rod. Besides, these lateral
points provide for an oblique discharge, each being as good a
receiving point as the higher jioint at the chimney or other prom-
inences. They also guard against a lateral explosion, or a divi-
sion of the charge, which is liable to happen in case the rod is
overcharged, especially if it be fastened to the house with pointed
stajiles ; and, in case of an ujDward sti'oke, the electric fluid being
discharged at so many diflferent points, no harm can possibly
occur.

" 6. Its upper extremity should project freely into the air,
should be pointed, and may be triangular, somewhat similar to a
bayonet, or it may have several bi'anches. The only scientific
advantage in having a branching head or point for the sui^erior
termination is this : all points are not likely to become blunt at
the same time. Some have supposed that the point should be
magnetized ; and little needles, called " magnets," have sometimes
been added. But it is difficult to see the practicability of this
recent discovery ; for most are aware that magnetized iron or
steel soon loses its magnetic influence. But is there an}' truth or
science in this application of magnetism? If there is, we confess
that we have not been able to discover it in any exijeriments in
the laboratory ; neither can we learn that the subject has even
been mentioned by any wi'iter whatever on the subject of elec-
tricity.

"7. The upper termination should be plated with silver or
gold, to prevent corrosion.

"8. Every branch rod running to chimneys and other promi-
nences should have a perfect metallic union with the main rod.

"9. In cases where metallic vane spindles, or other points,
exist, the conductor may commence from these, and should be
applied immediately to the part to be protected, and not at a dis-
tance from it ; and should be so applied that a discharge of light-
ning falling on the general mass could not possibly find its way
to the ground through the building by any circuit of which the
conductor did not form a part; that is to say, the conductor
should be so carried over the several parts of the building, that
the discharge could not fall upon it without being transmitted
safely by the conductor. Hence, the rod should run along the
whole length of the ridge, and down to the ground, at least on
two sides of the building. If the building is large, it should run
down on each corner.

" 10. Every conductor running to the ground should terminate

168 ANNUAL OF SCIENTIFIC DISCOVERY.

suiruicntlv beneath the suvlacc to insure moisture in the di-yest
part of the season. If circumstances permit, it should connect
■with a spring of water, a drain, or some other conducting
channel."

Numerous instances of the ascending stroke have occurred, the
records of which are extant. It must be evident that a single rod,
extending above only one point of the building, will not properly
protect the structure to which it is applicul from one of these up-
ward strokes, neither is it cllieient against an oblique or divided
discharge. The whole building, top and sides, must be protected
by a continuous rod with numerous projecting points for receiving
and discharging the electric lluid.

Passing the rod through glass insulators does not seem to be
always elfectual to pnjtect the building. The interposition of a
glass knob between the rod and the building, appears to be
preferable. In cases where the rod has passed tia-ough a hollow
cylinder of glass, it has l)e<Mi found that tlic glass would l)urst,
and the lluid enter the building by the iron staple which hekl the
glass ring.

Some of the old-fashioned and erroneous notions entertained
and religiously believtMl by j)ersons in relation to the ellects of
liglitning, and particularly the means of protection, have been
exploded by the occurrences of this season. That feathers afford
no protection against electricit}' is i^roved I)y the case of a woman
in St. Louis, who was killed by a stroke of lightning while lying
on a featlier bed. An instance of one of three persons sitting
near a closed window being struck also dispels the illusion that
the interposition of window-glass is an effectual bar to the action
of the destructive element.

The only elheient protection is that of a good i"od, properly put
up. The subject is too imjwrtant to be lightly })assed over ; and
it is no less important that the confidence of the purchaser should
not be betrayed, and life and property endangered, by accept-
mg an inelKeient conductor, or one improperly applied.

Many buildings are now constructed, both in this city and in the
country, with metallic-covered roofs, and very few are erected
without metallic eaves, troughs, and conductors. In all such
cases, the efficiency of lightning pi'otectors is impaired by the pre-
ponderance of conducting surface on the roof and down the sides
of the buildiu":. This metallic covering?, and these rain-conduc-
tors, whether of tin, zinc, or lead, are better conductors of elec-
tricity than the building of stone, brick, or wood, and should be
utilized as a means of protection against lightning. For this pur-
pose, strips of iron, zinc, or copper, should connect the lower
extremities of the water-spouts with the damp earth, a well, or
a running stream of water, and the eaves-troughs should have a
connection Avith the metal roofing and with the vertical conduc-
tors. Water is a good conductor of electricity ; and when, in a
thunder storm, the rain is jjouring down the conduits of a build-
ing, their conducting properties are largely increased. Properly
connected, these useful appliances can be mad6 doubly valuable
as hai-mless conductors of electricity.

NATURAL PHILOSOPHY. 169

In cities and enterprising towns there are systems of water-
pipes and gas-conductors, of metal, ramifying in tlie interior of
dwellings and other structures. Such buildings should be cai-e-
fully protected 'outside. If the conducting medium, whether of
water or gas-pipes, preponderates in the interior of the building,
the electric fluid may leave the external conductor, and through a
thick wall seek that which facilitates its passage to the earth. In
such cases, it seems that nothing but a rod, having numerous
points for collecting the electricity and adequate means for convey-
ing it innocuously to the earth, would be an etfectual protection.
Some authorities recommend a connection to be made between
the system of water and gas-pipes inside a building and the ex-
ternal conductor. — Scientijic American.

ALL THINGS IN MOTION.

In imagining the ultimate composition of a solid body, we have
to reconcile two apparently contradictory conditions. It is an
assemblage of atoms which do not touch each other, — for we are
obliged to admit intermolecular spaces, — and yet those atoms
are held together in clusters by so strong a force of cohesion as
to give to the whole the qualities of a solid. This would be the
case even with a solid undergoing no change of size or internal
constitution. But solids do change, under pressure, impact, heat,^
and cold. Their constituent atoms are, consequently, not at rest.
Mr. Grove tell us: "Of absolute rest, nature gives us no evi-
dence. All matter, as far as we can ascertain, is ever in move-
ment, not merel}' in masses, as with the planetary spheres, but
also molecularl}^ or throughout its most intimate structure.
Thus, every alternation of temperature produces a molecular
change throughout the whole substance heated or cooled. Slow
chemical or electrical actions, actions of light or invisible radiant
forces, are always at play ; so that, as a fact, we cannot predicate
of any portion of matter, that it is absolutely at rest."

The atoms, therefore, of which solid bodies consist are supposed
to vibrate, to oscillate, or better, to revolve, like the planets, in
more or less eccentric orbits. Suppose a solid body to be rc^jre-
sented by a swarm of gnats dancing in the sunshine. Each gnat
or atom dances up and down at a certain distance from each other
gnat, within a given limited space. The path of the dance is not
a mere straight line, but a vertical oval — a true oi'bit. Suppose,
then, that, in consequence of greater sun heat, the gnats become
more active, and extend each its respective sweep of flight. The
swarm, or solid body, as a whole, expands. If, from a chill or the
shadow of a cloud, the insect's individual range is less extensive,
the crowd of gnats is necessarily denser, and the swarm, in its
integrity, conti-aets.

Tyndall takes for his illustration a bullet revolving at the end
of a spiral spring. He had sj^oken of the vibration of tlie mole-
cules of a solid as causing its expansion, but he remarks that, by
some, the molecules have been thought to revoh'e round each
otlier ; the communication of heat, by augmenting their centrif-
15

170 ANNUAL OF SCIENTIFIC DISCOVERT.

ugal force, was supposed to push them more widely asunder.
So he twirls the wciglit at the end of the spring, in the open air.
It tends to fly away ; the spring stretches to a certain (sxtent, and
as the speed of re\olution is augmented, the spring stretches still
more, the distance between tlie hand and the weiglit being thus
increased. The spring rudely figures tlie force of cohesion, while
the ball rejn'csents an atom under tlie inlliience of heat.

The intellect, he truly says,