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Full text of "A history and handbook of photography"

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Erratum 
Page 320, line 22, for 12 ounces read 12 grains 



Tissnndier's Photography. 



PHOTOGRAPHY 



LONDON : I'KINTED BV 

SPOTTISWOODE AND CO., NEW-STKEET SQUARE 

AND PARLIAMENT STREET 








/- 



HISTORY AND HANDBOOK 



OF 



PH OTOGR A PH Y 

Translated from the French of 

GASTON TISSANDIER 



EDITED BY 

J. THOMSON, F.R.G.S. 

AUTHOR OF 'ILLUSTRATIONS OF CHINA AND ITS PEOPLE,' 'THE STRAITS OF 
MALACCA, INDO-CHINA, AND CHINA,' ETC. 



WITH UPWARDS OF SEVENTY ILLUSTRATIONS 



LONDON 
SAMPSON, LOW, MARSTON, LOW, & SEA RLE, 

CROWN BUILDINGS, l88 FLEET STREET 
1876 



NEW YORK 

S C O \' I L L MANUFACTURING COMPANY 

Nos. 419 «!y: 421 Broome. Street 

1877 



P R K FACE. 



Arago placed the daguerreotype amongst the most 
remarkable conquests of genius, by the side of the tele- 
scope and the electric battery. And indeed to every 
enlightened mind, the fixing of the image or picture of 
the * camera obscura ' or dark chamber by chemical agents, 
must appear a great event in the history of progress. 
An art so novel, capable of producing at the very outset 
such strange results, at once stamped itself as something 
grand, extraordinary, as a work full of vitality and 
vigour. 

Franklin's words with respect to the balloon, * It is 
the infant just beginning to grow,' could not have been 
applied to the daguerreotype, which has grown and 
prospered with such rapidity as to have had, $o to 
speak, no childhood or growth at all. The daguerreo- 
type is one of the latest of the prodigies of modern 
science ; it was discovered in 1838. 

The daguerreotype, as soon as born, transformed 
itself into the photograph. Hardly forty years have 



iv PREFACE. 



elapsed and the new invention has spread abroad and 
become so well known, that it has penetrated everywhere, 
in every civilised country, into the dwellings of the poor 
as well as of the rich. Unhappy indeed is he who can- 
not have recourse, for the picture of that which he loves; 
to photography, that sublime and beneficent art which 
gives us at such little cost the human visage in its exacti- 
tude, which presents to our eyes as in a mirror the scenery 
of distant lands, which lends its aid to all the sciences, 
which accompanies the astronomer into the depths of the 
heavens, the micrographer into the invisible world, and 
which even comes to the assistance of the besieged city, 
reducing its messages to the easy burden of a bird ! 

In studying the plan of this work, the author was 
impressed with the importance of the subject ; in writing 
it^ he experienced a deep admiration, which it has been 
his aim to impart to the reader. He has endeavoured to 
make his sketch at once a practical guide to the amateur 
photographer, and an attractive and instructive history, 
as is that of all scientific conquests when narrated with 
truth and sincerity. 

In this second edition which follows so closely on the 
first, some gaps, which the development of the art 
rendered in some degree inevitable, have been filled up 
from the large number of new facts which have come 
to light. 

G. T. 



CONTENTS. 



PART I. 

THE HISTORY OF PHOTOGRAPHY 



CHAPTER I. 

THE ORIGIN OF PHOTOGRAPHY. 

PACK 

J. B. PORTA AND THE DARK ROOM — FABRICIUS THE ALCHEMIST — 
LUNA CORNEA — PROFESSOR CHARLES'S SILHOUETTES — WEDG- 
WOOD, HUMPHRY DAVY, AND JAMES WATT .... I 

CHAPTER II. 

DAGUERRE. 

DEGOTTI THE SCENE PAINTER — EARLY LIFE OF DAGUERRE — IN- 
VENTION OF THE DIORAMA — THE CAMERA OR DARK ROOM — 
CHEVALIER THE OPTICIAN— THE HISTORY OF AN UNKNOWN — 
FIRST LETTER OF DAGUERRE TO NIEPCE I4 

CHAPTER III. 

NICfiPHORE NIEPCE. 

THE TWO BROTHERS NIEPCE — THEIR YOUTH — THEIR WORKS — THE 
PYRELOPHORE — HYDRAULIC MACHINE— NICfiPHORE'S RESEARCHES 
IN HELIOGRAPHY— RESULTS OBTAINED 26 



VI CONTENTS. 



CHAPTER IV. 

THE NIEPCE-DAGUERRE PARTNERSHIP. 

PAGE 

CORRESPONDENCE EXCHANGED BETWEEN THE TWO INVENTORS — 
DISTRUST AND RESERVE OF NIEPCE — HIS JOURNEY TO PARIS— 
HIS INTERVIEWS WITH DAGUERRE — HIS JOURNEY TO LONDON 
— ACT OF PARTNERSHIP — DEATH OF NIEPCE . . . . 40 

CHAPTER V. 

THE DAGUERREOTYPE. 

DAGUERRE'S RESEARCHES AND STUDIES— HE CEDES HIS INVENTION 
TO THE STATE — ARAGO AND THE DAWN OF PHOTOGRAPHY — 
A BILL LAID BEFORE THE HOUSE — REASONS FOR ITS BEING 
PASSED — MEETING OF THE ACADEMY OF SCIENCES, AUGUST lO, 

1839 53 

CHAPTER VI. 

THE PROGRESS OF A NEW ART. 

THE DAGUERREOTYPE PROCESS — ACCELERATING SUBSTANCES — IM- 
PROVED LENSES — PORTRAITS — FIXING AGENTS — DISCOVERY OF 
PHOTOGRAPHY ON PAPER BY TALBOT — M. BLANQUART-EVRARD 64 

CHAPTER VII. 

PHOTOGRAPHY. 

SIR JOHN HERSCHEL — HYPOSULPHITE OF SODA— NIEPCE DE SAINT- 

VICTOR'S NEGATIVE ON GLASS— GUN-COTTON AND COLLODION 79 



CONTENTS. VU 



PART II. 

THE OPERATIONS AND PROCESSES OF 
PHOTOGRAPHY. 



CHAPTER I. 

THE STUDIO AND APPARATUS. 

I'AGE 

ARRANGEMENT OF A GOOD STUDIO— THE DARK ROOM — TERRACE 
— SITTING ROOM — THE INFLUENCE OF LIGHT — ARRANGEMENTS 
FOR LIGHTING THE OBJECT TO BE PHOTOGRAPHED— THE APPA- 
RATUS — LENSES AND CAMERAS 89 

CHAPTER II. 

THE NEGATIVE. 

MANIPULATION OF THE PHOTOGRAPH— CLEANING THE PLATE — 
COATING THE PLATE WITH COLLODION— PLACING IT IN THE 
SILVER BATH — EXPOSURE IN THE CAMERA — DEVELOPMENT, 
FIXING AND VARNISHING I05 

CHAPTER III. 

THE POSITIVE ON PAPER. 

PRINTING ON PAPER— OF THE NATURE AND QUALITIES OF PHOTO- 
GRAPHIC PAPERS — VIGNETTES — EXPOSURE TO THE LIGHT — 
TONING— FIXING — ROLLING THE PROOFS 122 

CHAPTER IV. 

THEORY AND PRACTICE. 

EXPLANATION OF PHOTOGRAPHIC OPERATIONS— NECESSITY OF LONG 
PRACTICE — MODIFICATIONS IN PROCESSES REQUIRED BY DIF- 
FERENT SORTS OF PHOTOGRAPHY— PHOTOGRAPHY AND TRAVEL 
— LANDSCAPES — SKIES — PORTRAITS — INSTANTANEOUS PHOTO- 
GRAPHY . . 132 



Vlil CONTENTS. 



CHAPTER V. 

RETOUCHING. 

PAGE 

ACCIDENTS WITH NEGATIVES AND PROOFS— METHOD OF REMEDYING 
THE SAME — RETOUCHING THE NEGATIVE — IMPERFECTIONS IN 
THE POSITIVE— RETOUCHING PHOTOGRAPHIC PROOFS WITH 
INDIAN INK— COLOURING PHOTOGRAPHS —PHOTOGRAPHIC CARI- 
CATURES ■ . . . 141 

CHAPTER VI. 

ENLARGEMENT OF PROOFS, 

APPARATUS EMPLOYED FOR ENLARGING NEGATIVE PROOFS — WOOD- 
WARD'S SYSTEM — MONCKHOVEN'S APPARATUS— UNIVERSAL SOLAR 
CAMERA 147 

CHAPTER VII. 

PROCESSES. 

THE DRY COLLODION PROCESS — EMPLOYMENT OF ALBUMEN, HONEY, 
AND TANNIN — WAXED PAPER PROCESS— PERMANENT PHOTO' 
GRAPHY BY THE CARBON PROCESS — METHODS OF POITEVIN, 
SWAN, ETC . . • . 153 

CHAPTER VIII. 

PROBLEMS TO BE SOLVED. 

THE FIXING OF COLOURS— A MYSTIFICATION — EDMOND BECQUE- 
REL'S experiments— ATTEMPTS OF NIEPCE DE SAINT-VICTOR 
AND POITEVIN— PHOTOGRAPHIC PRINTING .... 169 



CONTENTS. IX 



PART III. 

THE APPLICATIONS OF PHOTOGRAPHY. 



CHAPTER I. 

HELIOGRAPHY. 

PAGE 

THE DAGUERREOTYPE PLATE TRANSFORMED INTO AN ENGRAVED 
PLATE — D0NN6 — FIZEAU — THE PHOTOGRAPHIC ENGRAVING OF 
NIEPCE DE SAINT-VICTOR — PHOTO-LITHOGRAPHY AND HELIO- 
GRAPHY INVENTED BY A. POITEVIN — PROCESSES OF BALDUS, 
GARNIER. ETC. — THE ALBERTYPE — OBERNETTER'S PROCESS — 
MODERN HELIOGRAPHY 1/9 

CHAPTER II. 

PHOTOGLYPTY (THE WOODBURY PROCESS). 

WOODBURY — IMPRESSION OF A GELATINISED PLATE INTO A 
BLOCK OF METAL— WORKING OF PHOTOGLYPTIC METHODS IN 
PARIS — DESCRIPTION OF MESSRS. GOUPIL'S ESTABLISHMENT — M. 
LEMERCIER I99 

CHAPTER III. 

PHOTOSCULPTURE. 

AN UNEXPECTED DISCOVERY — PHOTOGRAPHY APPLIED TO SCULP- 
TURE — WILLEME'S process IN 1861 — DESCRIPTION OF PHOTO- 
SCULPTURE 208 

CHAPTER IV. 

PHOTOGRAPHIC ENAMELS. 

VITRIFICATION OF A PHOTOGRAPH — CAMARSAC'S PROCESS— JEWELRY 
ENAMEL — METHOD OF MAKING— POITEVIN'S METHOD — PER- 
MANENT GLAZE PHOTOGRAPHS 2I4 



X CONTENTS. 



CHAPTER V. 

PHOTOMICROGRAPHY. 

PAGE 

THE TOY MICROSCOPES OF THE PARIS INTERNATIONAL EXHIBITIONS 
—450 DEPUTIES IN THE SPACE OF A PIN's HEAD — ARRANGE- 
MENTS OF PHOTOMICROGRAPHIC APPARATUS — THE NATURAL 
SCIENCES AND PHOTOMICROGRAPHY — RESOU^RCES BORROWED 
FROM THE HELIOGRAPH 220 

CHAPTER VI. 

MICROSCOPIC DESPATCHES DURING THE SIEGE OF PARIS. 

APPLICATION OF MICROSCOPIC PHOTOGRAPHY TO THE ART OF WAR 
—THREE MILLION PRINTED LETTERS OF THE ALPHABET ON 
THE TAIL OF A PIGEON — ENLARGEMENT OF THE DESPATCHES 
— THEIR CONVEYANCE BY CARRIER-PIGEONS .... 235 

CHAPTER VH. 

ASTRONOMICAL PHOTOGRAPHY. 

CELESTIAL PHOTOGRAPHY — DIFFICULTIES OF ASTRONOMICAL PHO- 
TOGRAPHIC OPERATIONS— MESSRS. WARREN DE LA RUE, RUTH- 
ERFURD, GRUBB, ETC. —THE LUNAR MOUNTAINS — THE SPOTS ON 
THE SUN, ETC. — IMPORTANCE OF PHOTOGRAPHIC DOCUMENTS 
FOR THE HISTORY OF THE HEAVENS . • , . . . 249 

CHAPTER Vni. 

PHOTOGRAPHIC REGISTERING INSTRUMENTS. 

IMPORTANCE OF REGISTERING INSTRUMENTS — PHOTOGRAPHIC BARO- 
METERS AND THERMOMETERS — THE REGISTRATION OF THE 
VIBRATIONS OF THE MAGNETIC NEEDLE— RONALD'S PHOTO- 
ELECTROGRAPH — PHOTOGRAPHIC PHOTOMETRY — PHOTOGRAPHY 
OF COLUMNS OF WATER RAISED BY A TORPEDO — OF THE 
PHENOMENA OF THE INTERFERENCE OF THE RAYS OF THE 
SPECTRUM 268 

CHAPTER IX. 

THE STEREOSCOPE. 

A FEW WORDS ON STEREOSCOPIC VISION— MEANS OF MAKING PHO- 
TOGRAPHIC PRINTS APPEAR IN RELIEF— WHEATSTONE'S STEREO- 



CONTENtS. xi 



PAGE 
SCOPE — MONOSTEREOSCOPE — HOW STEREOSCOPIC PHOTOGRAPHS 
ARE PRODUCED 287 

CHAPTER X. 

PHOTOGRAPHY AND ART, 

IS PHOTOGRAPHY ART? — ITS USES IN RELATION TO PAINTING, 
REPRODUCTION OF ENGRAVINGS, VOYAGES OF DISCOVERY — 
PHOTOGRAPHY BY THE MAGNESIUM LIGHT — PHOTOGRAPHIC 
PORTRAITS CONSIDERED AS HISTORICAL DOCUMENTS . * . 297 

CHAPTER XI. 

THE FUTURE OF PHOTOGRAPHY. 

LAND-SURVEYING — THE ART OF WAR— WORKS OF ART — CRIMINALS 
AND JUDICIAL PHOTOGRAPHY — THE MIRACLES OF INSTANTA- 
NEOUS PHOTOGRAPHY 306 



APPENDIX. 



PANORAMIC PHOTOGRAPHY -PANORAMIC CAMERA— THE HELIOTYPE 
PROCESS — THE PHOTO-TINT PROCESS — EPITOME OF THE WET 
COLLODION PROCESS AND USEFUL FORMULAE— SENSITISING BATH 
— DARK ROOM OPERATIONS— FIXING — POSITIVE SILVER-PRINT- 
ING FORMULA— SIMPLE METHOD OF PREPARING DRY PLATES 
— ENGLISH AND FRENCH WEIGHTS AND MEASURES . . -313 



INDEX 323 

ADVERTISEMENTS relating to photography . 327 et seq. 



LIST OF ILLUSTRATIONS. 



FULL-PAGE ENGRAVINGS. 

PORTRAIT FROM LIFE BY THE PHOTO-TINT PROCESS . Frontispiece 

PROFESSOR CHARLES'S EXPERIMENT .... To face p. ID 

DAGUERRE'S DIORAMA ,,13 

THE DARK ROOM . ,,90 

SPECIMEN OF A HELIOGRAPHIC ENGRAVING. (After a Draw- 
ing by Gustave Dore ) . . . . . . , , , 1 96 

THE SOLDIER OF MARATHON ,,197 

FACSIMILE OF THE PHOTOGRAPH OF A FLEA, OBTAINED BY 

THE PHOTOMICROGRAPHIC APPARATUS . . . ,, 23O 

ENLARGING MICROSCOPICAL DESPATCHES DURING THE SIEGE 

OF PARIS ,,241 

DEPARTURE OF CARRIER-PIGEONS FROM THE CHAMPS- 

^LYSfiES, PARIS ,, 247 

SALLERON's photographic barometer and THERMO- 
METER ,, 275 

photo-electrographic instrument at kew observa- 
tory, FOR REGISTERING THE STATE AND VARIATIONS 
OF THE ELECTRICITY OF THE AIR .... ,, 277 

IOCKYER'S APPARATUS FOR ANALYSING AN ALLOY OF GOLD 

AND SILVER BY THE PHOTOGRAPHY OF ITS SPECTRUM ,, 285 



XIV LIST OF ILLUSTRATIONS. 

APPARATUS FOR OBTAINING THE TWO PROOFS OF THE 

STEREOSCOPE To face p. 295 

FAC-SIMILE OF A STEREOSCOPIC PHOTOGRAPH . . . ,, 296 

PHOTOGRAPHY AND EXPLORATION ,, 302 

THE POLfiMOSCOPE ,, 307 



WOODCUTS IN TEXT. 

PAGE 

THE DARK ROOM 2 

THE IMAGE OF THE SUN FORMED ON THE SHADOW OF A TREE 3 

JOSEPH NIEPCE '44 

DAGUERRE 59 

DAGUERREOTYPE POLISHER 6$ 

MERCURIAL DEVELOPING BOX 66 

GILDING THE DAGUERREOTYPE PLATE 69 

PHOTOGRAPHIC BELLOWS CAMERA 94 

THE LENS, WITH ITS RACKWORK AND CAP .... 96 

SIMPLE PHOTOGRAPHIC APPARATUS 97 

THE CAMERA STAND 99 

THE DARK SLIDE IOC 

TWIN-LENS CAMERA, SHOWING DARK SLIDE AND DIAPHRAGMS . lOI 

THE HEAD-REST IO3 

PLATE-HOLDER I06 

COATING THE PLATE. FIRST POSITION OF THE HANDS . . IO9 

SECOND POSITION OF THE HANDS IO9 

SENSITISING TRAY . Ill 

SILVER HOOK FOR RAISING AND LOWERING THE PLATE . . Ill 



LIST OF ILLUSTRATIONS. XV 

PAGE 

GLASS BATH IN CASE WITH GLASS DIPPER . . . . 112 

WASHING THE DEVELOPED IMAGE II4 

RACK FOR DRYING PLA'.'ES II 8 

PLATE BOX . . ._ 119 

fHE PRINTING FRAME 124 

PRINTING FRAMES EXPOSED TO THE LIGHT . . . . I26 

SIMPLE PRINTING FRAME I26 

THE ROLLING PRESS 1 29 

PORTABLE PHOTOGRAPHIC APPARATUS I36 

PHOTOGRAPHIC CARICATURE I44 

MONCKHOVEN'S ENLARGING CAMERA I49 

LIEBERT'S ENLARGING APPARATUS I50 

THE SOLDIER OF MARATHON 1 97 

PHOTOGLYPTIC PRESS 202 

TURN-TABLE REQUIRED FOR TAKING PHOTOGLYPTIC PROOFS . 203 

PHOTO-ENAMEL BROOCH 217 

DUSTING-SIEVE 2X8 

TOY MICROSCOPE OF THE EXHIBITION OF 1 867 .... 220 

MICROSCOPE FITTED TO THE CAMERA ..... 224 

ARRANGEMENT OF THE PHOTOMICROGRAPHIC APPARATUS ON A 

BENCH 226 

VERTICAL MICROSCOPE ADAPTED TO THE CAMERA FOR PHOTOMI- 
CROGRAPHY 228 

PHOTOMICROGRAPHIC APPARATUS FOR ARTIFICIAL LIGHT . . 229 

FACSIMILE OF THE PHOTOGRAPH OF SECTIONS OF IHE STEM OF 

A CANE 230 

SECTION OF THE WOOD OF A FIR-TREE 23O 

GROUP OF DIATOMS 23I 



XVI LIST OF ILLUSTRATIONS. 

TAGE 

SECTION OF THE FIN OF A WHALE 232 

EPIDERMIS OF A CATERPILLAR 233 

CARRIER-PIGEON WITH PHOTOGRAPHIC DESPATCHES . . 236 

QUILL CONTAINING MICROSCOPIC DESPATCHES FASTENED TO A 

TAIL FEATHER OF CARRIER-PIGEON 237 

STAMPS, SHOWING WHEN DESPATCHES WERE FORWARDED OR RE- 
CEIVED, PRINTED ON THE WING 238 

FACSIMILE OF A MICROSCOPIC DESPATCH DURING THE SIEGE OF 

PARIS 239 

CHINESE WHISTLES ATTACHED TO CARRIER-PIGEONS . . . 245 

LUNAR MOUNTAINS. AFTER A PHOTOGRAPH BY MR. WARREN DE 

LA RUE 254 

UNDULATING LINES TRACED ON THE CARRIER OF THE ELECTRO- 
GRAPH .... 278 

BREWSTER'S STEREOSCOPE 29O 

HEIMHOLTZ'S STEREOSCOPE 29 1 

MONO-STEREOSCOPIC PRINT 292 

FEVRIER'S pillar STEREOSCOPE 293 

PLATE FOR SUPPORTING THE CAMERA WHEN TAKING STEREO- 
SCOPIC VIEW 295 

PHOTOGRAPHY BY THE MAGNESIUM LIGHT IN THE CATACOMBS 303 

PANORAMIC CAMERA 314 



PART I. 

THE HISTORY OF PHOTOGRAPHY. 



CHAPTER I. 

THE ORIGIN OF PHOTOGRAPHY. 

J. B. PORTA AND THE DARK ROOM — FABRICIUS THE ALCHEMIST — 
LUNA CORNEA — PROFESSOR CHARLES' SILHOUETTES — WEDGWOOD, 
HUMPHRY DAVY, AND JAMES WATT. 

The discovery of photography ranks amongst the most 
wonderful applications of modern science ; we owe it 
almost solely to the genius of Niepce and Daguerre. 
We shall mention the obstacles which these great minds 
had to overcome before solving a problem which had long 
been looked upon as Utopian ; we shall thus see with 
what perseverance the inventor must arm himself to 
attain his ends. But before relating facts we think it 
would be useful to look a little farther into the past to 
seek their causes. Nothing is more instructive than the 
impartial history of great discoveries ; it shows us how 
slow is the march of progress, and how many beacons 

B 



THE HISTORY OF PHOTOGRAPHY. 



must shine along the course of centuries to guide the 
inventor into the region of the unknown. First appears a 
man who sows the germ, others follow and cultivate it, 
up to the time when some genius fertilises and renders it 
fruitful. 

The germ of photography is the dark room (or 
camera obscura), discovered in the second half of the 
sixteenth century by J. B. Porta, a clever Italian philo- 

Fig. I. 




THE DARK ROOM. 



sopher. The process which the illustrious Neapolitan 
employed was most simple. He made an aperture, 
hardly large enough to admit the little finger, in the 
shutter of a window so perfectly closed as entirely to 
exclude light. The rays of light penetrating through 
the circular hole into the dark room were projected on 
to a white screen, on which they depicted the reversed 



THE ORIGIN OF PHOTOGRAPHY. 



image of exterior objects. (Fig. i.) The simple ob- 
servation of Nature might have led at once to this dis- 

Fig 2. 




THE IMAGE OF THE SUN FORMED ON THE SHADOW OF A TREE. 

covery. The foliage of trees does not entirely intercept 
the sun's light, it often allows rays of light to pass 



THE HISTORY OF PHOTOGRAPHY. 



through the spaces which exist between the leaves, and 
the images of the ruler of the day appear as luminous 
discs in the midst of the well-defined shadows on the 
ground. (Fig. 2.) It is easy to reproduce this pheno- 
menon by passing the light of a candle across a small 
orifice, and projecting it on to a screen, on which a re- 
versed imiage of the flame will be seen. 

Porta, in his treatise on ' Natural Magic,' goes into 
raptures, and excusably, over his discovery, of which he 
seems to have foreseen all the future importance ; he 
describes it with irrepressible admiration, and after 
describing it, exclaims with enthusiasm, 'We can dis- 
cover Nature's greatest secrets ! ' 

And truly, indeed, must those have wondered whom 
Porta initiated into the mysteries of his dark room ! 
With what bewilderment would they not contemplate 
this sharp, lifelike, and delicate picture, drawn by the 
light on a screen, which was thus transformed into a 
faithful mirror ! 

Soon, by means of a convex lens, fixed in the aper- 
ture in his shutter, and by the aid of a glass mirror 
which reversed the image. Porta was enabled to contem- 
plate the representation of exterior objects no longer 
reversed, but in their natural positions. Porta lost no 
time in recommending the use of the dark room to all 



THE ORIGIN OF PHOTOGRAPHY. 5 

painters desirous of obtaining exact and minute delinea- 
tion, and shortly afterwards Canaletto profited by his 
advice and employed the invention for taking his ad 
mirable views of Venice. 

What would the Neapolitan philosopher and the 
Venetian painter have said had they been told that this 
image of the dark room would one day draw itself, not 
merely fugitively, but that it would print itself on a glass 
moistened with chemical agents, that it would transform 
itself into a durable picture, only to be compared for 
exactness to the reflection of a mirror ? This wonder 
was, indeed, to be accomplished unknown to Porta ; but 
his work was not in itself sufficient to conduct science to 
such a result, numerous labourers had also to add their 
stone to the edifice. 

To find another of the original principles of photo- 
graphy we must quit Naples and transport ourselves to 
France, and to a little earlier epoch, when alchemy 
seemed to have attained its utmost development. It was 
in the middle of the sixteenth century that the action 
of light on the nitrates of silver was accidentally dis- 
covered by an alchemist. 

The few isolated observations which had been made 
up to this time were very incomplete and little known. 
The Greeks knew that the opal and amethyst lost their 



THE HISTORY OF PHOTOGRAPHY. 



brilliance if exposed to the lengthened action of the solar 
rays. 'Vitruvius had noticed that the sun altered and 
changed certain colours used in painting, and therefore 
always placed his pictures in rooms with a northern 
aspect. But such observations as these can hardly be 
considered as the results of scientific study. 

The alchemists have often been the subject of 
calumny. Though it is true that amongst the adepts 
in the ^ Black Art' there were numerous charlatans and 
quacks, it must not be forgotten that a large number of 
the philosophers of the middle ages, men of indefatigable 
research, were possessed with a real love of their art ; 
which they cultivated if not with method at least with 
invincible perseverance. It was one of these laborious 
workers who first' produced chloride of silver, and 
recognised the important property possessed by this 
substance of becoming black under the action of light. 

This disciple of Hermes was named Fabricius. One 
fine day, buried probably in the confusion of his labo- 
ratory, after having conjured up the devil and all the 
imps of darkness, after having in vain ransacked the 
books of magic, which swarmed in the middle ages, for 
the formula of that panacea which was to prolong life, 
cure all ills, and transmute the metals, he threw some 
sea salt into a solution of nitrate of silver and obtained 



THE ORIGIN OF PHOTOGRAPHY. 



a precipitate (chloride of silver) to which the alchemists 
of those times gave the name of ' Luna cornea,' or 'horn- 
silver,' He collected it, and what w^as his astonishment 
when he perceived that this substance, as white as milk, 
became suddenly black as soon as a ray of sunlight fell 
on its surface ! 

Fabricius continued to study this remarkable pro- 
perty, and in his ' Book of the Metals,' published in 1556, 
he relates that the image projected by a glass lens on to 
a surface of ' Luna cornea ' imprinted itself in black and 
grey, according as the parts were completely illuminated, 
or touched only by diffused light. But here the alche- 
mist stopped ; this fact, so full of significance, remained 
a dead letter in his hands. The science of those times, 
powerless through want of method, ignored the art of 
inferring from observation, and of confirming by expe- 
riments the deductions thus obtained. The chemists of 
this epoch could not see because their eyes had not been 
trained to look ; they let the fact escape and pursued 
the fancy ; like the dog in the fable, they abandoned 
the substance to grasp the shadow. What did it signify 
to Brandt if he discovered phosphorus, to Basile Valentin 
if antimony issued from his crucibles, to Albert the 
Great if nitric acid was distilled in his retort.'* all 
this, to these preoccupied minds, was not the philoso- 



8 THE HISTORY OF PHOTOGRAPHY. 

pher's stone. They did not deem it worth while 
to stop at such inventions. They passed on, and con- 
^demned themselves to wander in labyrinths without 
issues, they travelled through life as if impelled by fate 
towards a chimerical goal, which they could never reach. 
They groped along regardless of the great opportunities 
with which chance strewed their path, and did not even 
stoop to lift the gems which good fortune threw in their 
way ! 

Fabricius missed the principle of one of the most 
astonishing arts of modern times. Why was he not 
struck with some sublime presentiment, of which genius 
seems to have the secret } why was he not suddenly seized 
with one of those fortuitous inspirations which seem to 
be the birthright of true genius .? 

It was thus that, in 1760, a fantastical writer, 
though not a Fabricius, nevertheless divined photo- 
graphy. If Cyrano de Bergerac, born two centuries 
before balloons, may be considered as an aeronaut, 
Tiphaine de la Roche may be equally regarded as a 
photographer. This Tiphaine was a native of Nor- 
mandy and a great lover of eccentricities ; he has left 
us a whimsical book in which there is much that is 
astonishing, buried though it is in an indescribable 
medley of nonsense. In one of the chapters of this 



THE ORIGIN OF PHOTOGRAPHY. 9 

curious old book he relates how he was caught up in a 
hurricane and deposited in the domain of the genii, 
who initiated him in the secrets of Nature. 'You 
know,* said one of them to Tiphaine, * that rays of light 
reflected from different bodies form pictures, paint 
the image reflected on all polished surfaces — for example, 
on the retina of the eye, on water, and on. glass. The 
spirits have sought to fix these fleeting images ; ^ they 
have made a subtle matter by means of which a picture 
is formed in the twinkling of an eye. They coat a piece 
of canvas with this matter, and place it in front of the 
object to be taken. The first effect of this cloth is 
similar to that of the mirror, but by means of its vis- 
cous nature the prepared canvas, as is not the case 
with the mirror, retains a facsimile of the image. The 
mirror represents images faithfully, but retains none ; our 
canvas reflects them no less faithfully, but retains them 
all. This impression of the image is instantaneous. 
The canvas is removed and deposited in a dark place. 



* This recalls a Chinese tradition which accords to the sun the power 
of photographing a landscape on a sheet of ice. An ancient sage, it is 
said, discovered a picture of the trees and shrubs on the banks of a stream 
engraven on its frozen surface. It seemed as if the reflected image were 
caught and frozen on the ice. But this early example of photography, 
if it ever existed at all, may have been produced by a powerful gleam 
of the hot sun of North China tracing the outlines of shadows thrown 
across a dark surface of ice thinly covered with snow. — Ed. 



10 THE HISTORY OF PHOTOGRAPHY. 

An hour after the impression is dry, and you have a 
picture the more precious in that no art can imitate its 
truthfulness.' 

In writing these truly prophetic lines, had Roche no 
knowledge of the book of F'abricius, or rather had he 
not himself experimented .with Porta's dark room, in sup- 
posing, as though in a dream, that the fleeting reflection 
had been fixed for ever ? We cannot say. But however 
that may be, to find really serious and scientific studies 
we must come down to the end of the eighteenth cen- 
tury — to that period, the most surprising perhaps in the 
history of progress, when the gloom of the past dispersed, 
when light appeared, when the savant rubbed his eyes 
and for the first time looked around him. 

In 1777, Scheele, the great Swedish chemist, dis- 
covered that chloride of silver is much more sensitive to 
blue and violet rays than to those of a green and red 
colour. About the year 1780, Professor Charles, the 
inventor of the hydrogen gas balloon, made the first 
use of the dark room for attempting to produce rudi- 
mentary photographs. He exhibited to the numerous 
and attentive audience at his course of lectures on 
natural science a curious, and at that time even 
wonderful experiment. By means of a strong solar ray, 
he projected a shadow of the head of one of his pupils 



THE ORIGIN OF PHOTOGRAPHV. II 

on to a sheet of white paper which had previously been 
soaked in a solution of chloride of silver. Under the 
influence of the light it was not long in becoming black 
in the parts exposed, remaining white on that portion of 
the sheet which had been shaded, and thus giving a 
faithful silhouette of the person's head in white on a 
black ground. (Fig. 3.^) This sheet of paper, which 
seemed as though endowed with magical properties, was 
passed from hand to hand ; but soon the light acting on 
the silhouette till then white, blackened it like the ground, 
and the profile disappeared little by little as though 
blotted out with ink. 

Professor Charles also reproduced, roughly, it is true, 
some engravings which he placed on a sensitised paper. 
The details of this experiment are, however, for the 
most part wanting in the historical documents relating 
to his works. 

Wedgwood, a clever English scientist, made a similar 
experiment to Professor Charles' ; he projected the image 



J Our illustration of this curious experiment of the celebrated chemist 
is based on the rather vague and incomplete accounts which were given of 
it at the time of its exhibition by Professor Charles. We suppose in our 
engraving that the experiment is just commencing ; the silhouette of the 
person is in black ; a few moments later, the part of the paper represented 
as white will become black, and, when the person retires, it is his shadow 
seen in black, which appears in white because the light could not affect 
this part of the silvered paper. 



12 THE HISTORY OF PHOTOGRAPHY. 

of the dark room on to a sheet of paper similarly sen- 
sitised, and obtained a rough picture, which could only 
be preserved in the dark. In 1802 Wedgwood and Sir 
Humphry Davy published a remarkable treatise on the 
reproduction of objects by light.' 

James Watt, the celebrated inventor of the steam 
engine, also studied this singular phenomenon ; and the 
problem of fixing the image of the camera occupied his 
great mind for some time ; but the results he obtained 
were doubtless insignificant, for he does not refer to 
them at all in his writings. It was much the same with 
the great English chemist, Humphry Davy, who has 
left us a few lines on the subject of Wedgwood's experi- 
ment. 

* All that is wanting,' said he, ' is a means of pre- 
venting the lights of the picture from being afterwards 
coloured by daylight ; if this result is arrived at, the 
process would become as useful as it is simple. Up to 
the present time it is necessary to keep the copy of the 
picture in the dark, and it can only be examined in the 
shade, and then but for a short time. I have tried in 

* This method was also employed to delineate profiles, or shadows of 
figures, the woody fibres of leaves, wings of insects, &c. Chloride of silver 
in a wet state was found to be more susceptible to the influence of light 
than nitrate of silver. Pictures produced at this time could not be 
fixed. — Ed. 



THE ORIGIN OF PHOTOGRAPHY. 1 3 

vain every possible method of preventing the uncoloured 
parts from being affected by the light. As for the 
images of the dark room, they were doubtless not suffi- 
ciently illuminated to enable me to obtain a visible 
picture with the nitrate of silver. It is that, nevertheless, 
which is the great point of interest in these experiments. 
But all attempts have been fruitless.' 

The problem which Davy thus clearly describes, and 
which neither Charles, Wedgwood, Watt, nor himself 
could solve, was destined to be overcome by two French- 
men, whose names ought to be reckoned amongst the 
glories of the national genius. 



14 THE HISTORY OF PHOTOrxRAPHY. 



CHAPTER- II. 

DAGUERRE. 

DEGOTTI THE SCENE-PAINTER— EARLY LIFE OF DAGUERRE— INVEN- 
TION OF THE DIORAMA — THE CAMERA OR DARK ROOM — 
CHEVALIER THE OPTICIAN — THE HISTORY OF AN UNKNOWN— FIRST 
LETTER OF DAGUERRE TO NIEPCE. 

At the commencement of the present century there 
was at Paris a scene-painter of the name of Degotti, who 
painted the finest scenes of the Grand Opera. At his 
celebrated studio this master produced truly wonderful 
pictures. He taught numerous pupils who by their 
natural disposition were drawn more towards inde- 
pendence of colour and freedom of pencil than towards 
the school of the Academy. One of the followers of 
Degotti soon signalised himself by his rare talents ; 
he attacked the canvas with the ardour of an artist 
thoroughly imbued with the grand effects of paint- 
ing. The name of this promising debutant was 
Daguerre. 

Daguerre was born in 1787 at Cormeilles near Paris. 



DAGUERRE. 1 5 



In the midst of the political paroxysms and cataclysms 
of the great Revolution his childhood was singularly neg- 
lected. Arrived at a suitable age, his parents allowed 
him to make his own choice of a profession. The youth- 
ful Daguerre gladly chose the career of an artist. From 
his tenderest childhood, as soon, indeed, as he could 
hold it between his fingers, he had exhibited a wonder- 
ful facility with the pencil. He excelled in rendering 
with fidelity the most difficult effects of the boldest per- 
spective, he studied especially scenic effect, and he thus 
soon found himself at home in Degotti's studio, where 
he was not long in equalling and then excelling the 
talent of his master. 

Not only was young Daguerre a genius at landscape 
scene-painting, the specialite of scene-painters, but he 
could readily solve the mechanical problems relating to 
the mysteries ' behind the scenes.' such as fixing, shift- 
ing, &c. He substituted for the movable frames of the 
side scenes large canvas backgrounds on which a whole 
vast landscape or an entire panorama could be repre^ 
sented. But not content with producing a masterly 
picture, he conceived the idea of giving it a value until 
then unknown, by having recourse to the untried re- 
sources of powerful illumination. His first attempts 
met with unexpected success. The unknown artist of 
yesterday had become the pet of the Parisian populace. 



1 6 THE HISTORY OF PHOTOGRAPHY. 

At the Opera, at the Ambigu Comique, in * The 
Dream,' in ' The Wonderful Lamp,' in * The Vampire,' 
the scenes of the new painter had an immense success 
every night. The papers and theatrical journals spoke 
of nothing but the effects of the rising moon and the 
setting sun ; and the name of Daguerre flew from mouth 
to mouth, carried by the eclat so resounding in Paris, es- 
pecially when it celebrates anything which affects the 
pleasures of the public. ' 

But Daguerre did not rest content with this ; he 
aimed at a more lasting fame ; his success far from ele- 
vating served only to stimulate him : he dreamt of new 
triumphs, and in spite of the dissipations of Parisian life, 
he never forgot that work and perseverance are the two 
levers capable of raising great results. He had doubt- 
less to struggle with the enticements of pleasure, for his 
temperament was ardent and his spirits lively and imagi- 
native. Educated in the midst of art studios and 
theatres, and naturally gay and light-hearted, he was a 
very * gamin de Paris,' as several well-authenticated facts 
in his biography sufficiently show. Unusually agile, he 
was at home in all manly sports ; he excelled in throwing 
summersaults and feats of strength, and he would some- 
times at social gatherings amuse his friends by walking 
on his hands with his legs in the air. It is even said 



DAGUERRE. 1/ 



that he loved to appear incognito on the stage at the 
Opera, where his paintings excited universal admiration. 
He donned the costume of the ballet corps and figured 
in chorographical acts, amused at the applause of the 
public, which had not the least idea that under the dress 
of this dancer was hidden an inventor of genius. But 
these somewhat puerile amusements did not hinder 
Daguerre from working, and dreaming of success 
and fame. His ingenious and inventive mind, once 
entered upon the road to celebrity, would follow it, mark- 
ing each of his steps with a new conquest ; his inven- 
tion of the Diorama excited universal enthusiasm, 

July I, 1822, saw crowds of people streaming towards 
a new establishment on the Boulevard. They were for 
the first time going to see a spectacle which was to be for 
many years an object of general admiration. Daguerre 
had entered into partnership with the painter Bouton, 
and together they had conceived the idea of imitating 
nature by means of immense sheets of canvas, the sub- 
jects on which were thrown in relief by a powerful and 
well-arranged system of lighting. 

These Dioramic scenes represented views, interiors, 
and landscapes with wonderful fidelity, and with a truly 
surprising finish in execution. But that which especially 
excited the admiration of the spectators was the gradual 

C 



1 8 THE HISTORY OF PHOTOGRAPHY. 

changing of the scenes, which appeared, so to speak, to 
dissolve into one another, one following another without 
appreciable interruption. All Paris wentto see Daguerre's 
Diorama, and applauded the beautiful pictures of the 
Valley of Sarnen, of the Tomb of Charles X. at Holy- 
rood, and of the Basilica of St. Peter. The effects pro- 
duced by the dioramic canvas were as beautiful from an 
art point of view as they were curious as changes of 
scene. 

One contemplated, for example, the Valley of Goldau, 
where fir-trees crowned as with a diadem of verdure the 
cottages of a humble village sleeping on the borders of a 
peaceful lake ; then suddenly the sky became gloomy, 
dark threatening clouds appeared, a violent concussion 
shook the mountain, the avalanche descended, impetuous, 
terrible, it rushed on the village, burying it in ruins ; to 
the peaceful picture of but a moment before, had suc- 
ceeded a dreadful scene of falling and crashing rocks in 
indescribable confusion. 

We are at the present day acquainted with the 
secrets of the Diorama, which, however, our space will not 
permit us to describe fully ; but it played such an im- 
portant part in the life of Daguerre that we cannot pass 
it by entirely in silence. The accompanying engraving 
shows the general aspect of the apparatus. We may 



DAGUERRE. 1 9 



add that the canvas was painted on both sides, and that 
as the light was thrown on the front or back — that is 
to say, reflected or transmitted — the one or the other 
picture appeared, and thanks to this ingenious artifice 
the spectator admired the changes of scenes so rapid and 
surprising. 

The success of the Diorama did not content Daguerre, 
and a still more brilliant fortune was in store for this 
active and ambitious mind. 

In executing his pictures, Daguerre constantly em- 
ployed the camera obscura (or dark room) ; he en- 
deavoured to reproduce faithfully the lively picture 
which the light after passing through the crystal of a 
lens traced on the screen at the back of his camera, but 
he felt that his art was powerless to copy such a model, 
that his genius strove in vain against obstacles which no 
painter could overcome. The dark room gave him 
nature to the life ; it was life, truth, and colour which 
he daily contemplated on his screen. ' Why,' cried he, 
'cannot I retain these inimitable wonders which the 
sun's rays draw at the focus of my lens ? Why cannot I 
fix the image, engrave it for ever ? ' 

Thus Daguerre nourishes this fantastic dream in- 
cessantly in his brain. He has not knowledge enough 
to comprehend all the difficulties of such a problem, nor 



20 THE HISTORY OF PHOTOGRAPHY. 

is he ignorant enough to believe that its solution is an 
impossibility. He is acquainted with Professor Charles' 
experiment ; he has heard talk of the shadows which im- 
print themselves so clearly on the sensitised paper ; he 
feels that the first step has been taken, that a supreme 
effort might enable a bold mind to bridge the abyss 
which separates the isolated fact from the grand solu- 
tion. This effort it will be his aim to accomplish. For 
the future he will have no rest until he can exclaim, like 
Archimedes, ' I have found.' 

Daguerre used very often to go to the shop of 
Chevalier, the optician on the Quai de L'Horloge, in 
order to procure all the apparatus he could pertaining 
to the dark room. 

' It was very seldom,' says Charles Chevalier himself,^ 
' that he did not come at least once in the week to 
our studio. As may be easily imagined, the subject of 
conversation did not vary much, and if now and then it 
digressed a little, it was only to return with fresh ardour 
to the arrangement of the dark room, the form of lenses, 
or the purity of the pictures ! ' 

At this time Chevalier's shop was much frequented 
by amateurs and others who came to obtain from the 
optician similar information to that which Daguerre was 

' Guide du Photographe. Paris, 1 854. 



DAGUERRE. 21 



in quest of. Chevalier mentions a circumstance which 
occurred at his shop in 1825, which seems to us so 
curious that we have felt bound to relate it, as one of the 
stirring chapters in the history of the fixation of the 
image of the camera. 

One day a young man, poorly dressed, timid, 
miserable, famished-looking, entered the optician's 
shop ; he approached Chevalier, who was alone, and 
said to him, * You are making a new camera in which 
the ordinary lens is replaced by a convergent meniscus 
glass : what is the price ? ' 

The optician's reply made his questioner turn yet 
paler. The cost of the object in question was doubtless 
as far above his means as if it had been equal to the 
riches of Peru or California. He lowered his head sadly 
without speaking. 

'May I enquire,' continued Chevalier, 'what you 
intend doing with a camera ?' 

' I have succeeded,' replied the unknown, ' in fixing 
the image of the camera on paper. But I have only a 
rough apparatus, a deal box furnished with an object- 
glass ; by its aid I can obtain views from my window. 
I wished to procure your improved camera lens in 
order to continue my experiments with a more powerful 
and certain apparatus.' 



22 THE HISTORY OF PHOTOGRAPHY. 

Whilst listening to these words Chevalier said to 
himself, * Here is another of these poor fools who want 
to fix the image of the camera obscura!' He well 
knew that the problem engaged the minds of such men 
as Talbot and Daguerre, but none the less deemed it a 
Utopian dream. 

* I know,' said he, * several men of science who are 
engaged with this question, but as yet they have 
arrived at no result. Have you been more fortunate?' 

At these words the young man pulled out an old 
pocket-book which was quite in keeping with his dress ; 
he opened it and quietly drew out a paper which he 
placed on the counter. 

* That,' said he, ' is what I can obtain.' Chevalier 
looked at it and could not control his astonishment ; he 
saw on this paper a view of Paris as sharp as the image 
of the camera. It was not a drawing nor a painting ; 
one might have said it was the shadow of the roof, 
chimneys, and dome of the Pantheon. The inventor 
had fixed the view of Paris as seen from his window. 

Chevalier questioned the young man further, and the 
latter then drew from his pocket a vial containing a 
blackish fluid. * You have here,' said he, ' the liquid 
with which I operate, and if you follow my instructions 
you will obtain like results.' 



DAGUERRE. 23 



The unknown explained to the optician how he 
should go to work ; then he retired, lamenting his hard 
fate which would not permit him to possess that object 
of his dreams, a new camera ! He promised to return, 
but disappeared for ever. 

Chevalier endeavoured to put in practice the instruc- 
tions he had just received ; but it was in vain that he 
made his experiments, he obtained absolutely no result 
with the liquid of his unknown visitor. It is probable 
that he did not operate under good conditions, and it 
is even possible that he omitted to prepare his sensitised 
paper in the dark. He waited long for another visit 
from the unknown, feeling somewhat remorseful at 
having been so reserved. He never saw him again. 

The name of this poor inventor is lost. It was never 
discovered what became of him. It may be, alas ! that 
an almshouse bed was his last refuge. 

Chevalier related this curious episode to Daguerre, 
who paid little attention to it while he carelessly ex- 
amined the remainder of the stranger's black liquid ; his 
mind was too preoccupied with researches of its own to 
attach much value to the work of another. 

It will thus be se^n that the history of this unknown 
person is worthy of fixing the attention for a moment; 
for, though it was fruitless, it is but fair to mention it as 



24 THE HISTORY OF PHOTOGRAPHY. 

the work of a man, of genius perhaps, whom poverty 
has fatally condemned to oblivion ! 

But to return to Daguerre. We find him pursuing 
his researches with fresh energy. He has constructed a 
regular laboratory provided with all the necessary appa- 
ratus and innumerable chemicals ; he studied the re- 
agents, he experimented unceasingly, ever anxious to 
attain a result looked upon as chimerical by men of 
science. Ere long Daguerre declared that he had suc- 
ceeded in fixing the fugitive image, but, nevertheless, 
gave no proof whatever that he had done so. In De- 
cember 1825 he told everyone who would listen to him 
that the great problem was at last solved. ' I have 
seized the light,' he cried with enthusiasm ; ' I have 
arrested its flight! The sun himself in future shall draw 
my pictures ! ' 

A few days later, in January 1826, he called on 
Chevalier to talk of his favourite subject. * Besides the 
young man I spoke to you about,' said the optician, ' I 
know a person in the country who flatters himself that 
he has obtained the same result as you. He has for a 
very long time occupied himself with reproducing en- 
gravings by the action of light on certain chemical 
agents. Perhaps you would do well to put yourself in 
communication with him.' 



DAGUERRE. 25 



* And what is the name of my fortunate rival ? ' de- 
manded Daguerre. 

Chevalier wrote a few words on a piece of paper 
which he handed to Daguerre. On it was this address — 
* M. Niepce, proprietaire, au Gras, pres Chalons-sur- 
Saone.' 

'^ A few days afterwards Daguerre addressed a letter 
to this stranger, which the latter, with provincial mis- 
trust, threw into the fire as soon as he had read, content- 
ing himself with murmuring between his teeth, ' There 
is another of those Parisians who would like to pump 
me!'^ It was under these auspices that the relations 
between the two inventors commenced ; they were, 
however, later on to unite their labours to create, as it 
were in common, an art which will be looked upon 
for centuries to come as one of the prodigies of our 
epoch. 

^ History of the Discovery improperly called '■Daguerreotype,^ preceded by a 
Notice of its real Inventor, the late M. Joseph Nice phore Niepce, by his Son, 
Isidore Niepce. Paris, 1841. 



26 THE HISTORY OF PHOTOGRAPHY. 



CHAPTER III. 

NICEPHORE NIEPCE. 

THE TWO BROTHERS NIEPCE — THEIR YOUTH — THEIR WORKS — THE 
PYRfiLOPHORE— HYDRAULIC MACHINE— NIC^PHORE'S RESEARCHES 
IN HELIOGRAPHY — RESULTS OBTAINED. 

JOSEPH-NlCEPHORE NiEPCE was born at Chalons-sur- 
Saone on March 7, 1765. His life and works are so 
interwoven with those of his elder brother Claude, to 
whom he was devotedly attached, that their history is a 
joint one, like that of the Brothers Montgolfier. We 
shall see them walk side by side through life, mutually 
sustaining and helping each other. 

Their father, Claude Niepce, was steward to the 
Duke of Rohan-Chabot ; their mother was the daughter 
of a celebrated barrister, Barault by name. 

'Joseph and his brother Claude,' says one of their 
biographers, ' were brought up with great care and soli- 
citude by their father. Their tutor was the Abbe 
Montangerand, a very clever man. 

* . . . The brothers made rapid progress in Ian- 



NICEPHORE NIEPCE. 2/ 

guages, sciences, and belles-lettres. They had real love 
for learning, and being of gentle and tinfid dispositions, 
were content in themselves, not joining in the games 
and amusements usual to children of their age. They 
seemed born for the contests of the mind and intel- 
lect. Nicephore and Claude employed their play 
time in constructing little machines of wood with cog 
wheels, with the aid of their knives only. These 
machines worked well, to the great joy of their makers ; 
they imitated the raising and lowering movements of the 
crane.' ^ 

Nicephore Niepce, like Daguerre, like all the men of 
his time, had to submit to the influence of the great 
Revolution. On May lo, 1792, he changed the clerical 
dress, which he had till then worn, for the military cos- 
tume, and entered as sub-lieutenant in the 42nd regi- 
ment of the line. 

Young Niepce was made lieutenant on the i6th 
Floreal of the year I. of the Republic (May 6, 1793), 
and took part in the expedition to Cagliari, in Sardinia. 

* We borrow these remarks on the life of Niepce from a remarkable and 
rare pamphlet by M. Victor Fouque, entitled The Truth with respect to the 
Invention of Photography. Nicephore Niepce^ his Life, Essays, and Works, 
fro7n his Correspondence and other unpublished Documents. Paris, 1867. The 
author of this pamphlet, which excited great attention on its first appear- 
ance, has, unhappily, fallen into totally erroneous ideas with regard to 
Daguerre, to whom he would deny any part in the creation of photography. 



28 THE HISTORY OF PHOTOGRAPHY. 

The same year (1793) he figures in the ranks of the 
army of Italy,*partaking in its glorious exploits. The 
1 8th Ventose, year II. (March 9, 1794) he was appointed 
assistant to adjutant-general Frottier, shortly after he 
was suddenly attacked by a severe and dangerous ill- 
ness, which obliged him to leave the regiment and seek 
an asylum in the town of Nice. There, thanks to the 
care of the mistress of the house in which he lived, 
Madame Romero, and the devotion of her daughter 
Mademoiselle Marie-Agnes, he regained his health. But 
whilst regaining his health he had been losing his heart, 
which he at last offered to Miss Marie-Agnes, and they 
were married the 17th Thermidor of the year II. 
(August 5, 1794). 

But the illness he had undergone had affected his 
constitution, and, obliged to give up his military 
career, he retired to Saint Roch, near Nice, where he 
lived with his wife and his brother Claude. It was 
during their stay at Saint Roch that the brothers 
conceived the idea of a motive power to propel 
ships without the aid of sails or oars. The machine 
which the brothers invented was put in motion by hot 
air ; they gave it the name of the pyrdophore, and, as 
soon as they returned to their native town of Chalons, 
they fitted up a boat with their new apparatus and ran 



NICEPHORE NIEPCE. 29 

it on the Saone. Later on, when the Government 
of the First Empire ofifered prizes for an improved 
hydraulic machine to take the place of Marly's, the 
brothers Niepce sent in the model of a pump which was 
as simple as it was ingenious, and for this new system, as 
also for their pyrelophore, they were thanked by the 
Institute. 

During the Continental blockade, the Government 
called on men of science if possible to replace the indigo 
procured from abroad, and so useful in dyeing wools, by 
ivoad, the juice of which might in some way be employed 
in the art of dyeing. In answer to the appeal the brothers 
turned their attention to the subject, and materially 
helped to lay the foundation of a new culture. In the 
years preceding the fall of the First Empire they ren- 
dered the greatest services to France. 

But the two brothers were soon obliged to separate. 
In 181 1 Claude quitted the paternal roof at Chalons, 
never to return, and went to Paris. His purpose was to 
launch the pyrelophore, and the great town seemed to 
him to be the only place where his work might at length 
be crowned with success. But against the invincible 
obstacles in his way all his efforts were in vain ; he 
failed alike in his trials and in his applications. 

He left Paris and France and settled definitely at 



30 THE HISTORY OF PHOTOGRAPHY. 

Kew near London. The two brothers, thus separated 
by exigency and distance, kept up an unbroken corre- 
spondence, which M. Foque has published in his beau- 
tiful book dedicated to the memory -of one of the 
inventors of photography. These letters are a rare 
example of mutual affection and solicitude, in which the 
ingenious conceptions of the laborious minds are as 
numerous as the marks of affection of tender and devoted 
hearts. 

Living alone in his country-house at des Gras near 
Chalons, Nicephore Niepce devoted himself assiduously 
to his researches, which were encouraged by the quiet 
country life and sweet solitude of the paternal home. 

It was a simple and modest building, this cradle of 
photography, shaded by a few trees and situate on the 
bank of the Sa6ne, which gave it a sweet and vivifying 
freshness. Under this humble roof, Niepce devoted ten 
years of his life to solving the problem of the fixing of 
the picture of the camera obscura. 

After his numerous researches in the making of new 
machines, in the cultivation of woad, &c., Nicephore 
turned his attention into a new direction, when litho- 
graphy made its appearance in France. This great dis- 
covery of the German Aloys Senefelder was brought 
into France in 1802 by the Count de Lasteyrie-Dus- 



NIC^PHORE NIEPCE. 3 I 

saillant, who, ten years after his first attempts, founded 
an admirable Lithographic Institution in Paris. This 
new art met with universal success. Niepce partook 
of the general enthusiasm, became enraptured with 
lithography, and taught himself how to use its appliances ; 
but, far from Paris, he could not procure proper appa- 
ratus and stones, he therefore determined to make them 
for himself. 

'In 1813,' writes his son Isidore Niepce, 'my father 
made some attempts at engraving and reproducing 
drawings, by lithography, which had recently been in- 
troduced into France, and which attracted his admi- 
ration. Some broken stones, intended for repairing 
the main road between Chalons and Lyons, which came 
from the Quarries of Chagny, seemed to him to be 
suited, from the fineness of their grain, to be usefully 
employed in lithography. We chose some of the largest 
of these stones, and my father had them polished by a 
marble-worker of Chalons ; I then made various drawings 
on them, which my father coated with a varnish he had 
prepared ; he then etched them by means of an acid. 

' But finding that the grain of these stones was not 
sufficiently fine and regular, my father replaced them by 
polished tin plates ; he coated these plates with various 
varnishes, then placed on them the drawings which he 



32 THE HISTORY OF PHOTOGRAPHY. 

had previously varnished to render them transparent, and 
exposed the whole to the action of light. This was 
the commencement, very imperfect if you like, of helio- 
graphy.' 

Once on the road to discovery, Niepce continued his 
studies with that unwearying perseverance of which the 
inventor seems to have the sole monopoly. 

He was not long in having recourse to the camera, 
but he was alone in a country far from any scientific 
centre, and he had to tax his ingenuity and make for 
himself what he wanted ; he was his own cabinet-maker 
and optician, he manufactured his cameras and his ap- 
paratus, and as a rest from his labours took the pen and 
opened his heart to his dear Claude. His progress in 
heliography was rapid, as is proved by the following 
letter (a remarkable document and precious for the his- 
tory of photography), dated May 5, 18 18, which we repro- 
duce entire : — 

' You have seen,' he says to his brother, * that I had 
broken the object-glass of my camera ; but that I had 
another which I hoped to be able to make use of My 
attempt was a failure ; this glass has a shorter focus than 
the diameter of the box, and so I could not make use of 
it. We went to town last Monday ; I could only find at 
Scotti's a lens of longer focus than the first, and I have 



nic:6phore niepce. 33 



had to lengthen the tube which holds it, and by means of 
which the exact focus is adjusted. We returned here 
Wednesday evening ; but since then the weather has 
always been dull, preventing me from continuing my 
experiments ; moreover, I am too worried and fatigued 
with paying or receiving visits to be able to give much 
attention to them. I would prefer, I assure you, to live 
in a desert. 

* When my object-glass was broken, no longer 
being able to make use of my camera, I made an arti- 
ficial eye with Isidore's ring box, a little thing from 
16 to 18 lines square. I had, luckily, the lenses of the 
solar microscope, which, as you know, belonged to, our 
grandfather Barrault. One of these little lenses proved 
to be exactly of the focus wanted ; and threw a picture 
of objects in a very sharp and life-like manner on to a 
field of thirteen lines diameter. 

' I placed this little apparatus in my workroom facing 
the open window looking on to the pigeon-house. I 
made the experiment in the way you are acquainted with, 
my dear friend, and I saw on the white paper the whole 
of the pigeon-house seen from, the window, and a faint 
impression of the window frame itself which was not ex- 
posed to the sunlight. One could distinguish the effects 
of the solar rays in the picture from the pigeon-house up 

D 



34 THE HISTORY OF PHOTOGRAPHY. 

to the window-sash. This is but a very imperfect ex- 
p)eriment, but the images of the objects were extremely 
minute. The possibility of painting by this means 
appears almost clear to me ; and if I am able to perfect 
my process, I shall hasten to respond to the interest 
which I know you will take in it, by imparting it to you. 
I do not hide from myself that there are great diffi- 
culties, especially as regards fixing the colours, but with 
work and patience one can accomplish much. What 
you had foreseen has proved true. The ground of 
the picture is black, and the objects are white, that is 
to say lighter than the ground.' 

In the course of his correspondence with his brother, 
Nicephore continually mentions his efforts, researches, 
and experiments. On May 19, 18 16, he says to him, * I 
shall occupy myself with three things ; 1st. To give 
more relief to the representation of the objects. 2nd. To 
transpose the colours [by this must, most likely, be 
understood, to reproduce the exact tones of nature] ; 3rd 
and lastly to fix them, which will not be easy.' On the 
28th of the same month he sent Claude four metallic 
plates which bore impressions produced by light. Un- 
fortunately, it is impossible to know what substance 
Nicephore used for sensitising his plates ; through pru- 
dence and from fear of some indiscretion he never men- 
tions it in any of his letters. His writings, however, show 



NIC^PHORE NIEPCE. 35 

US that whatever it was, h£ was not satisfied with it ; for 
he says later on, in a letter to his brother, that he had 
been trying to make use of alcoholic solutions of chloride 
of iron. In 1817, he had recourse, in h\s Heliographic 
studies, as he already calls them, to chloride of silver, and 
then to organic matters such as guaiacum (a resin), and 
at last to phosphorus, which, as is well known, from white 
turns gradually to a red colour under the action of light. 
But he was not long in love with this new agent, which 
he very justly terms a ' dangerous combustible.' 

On July 2, 1 8 17, he declares that his efforts have 
not yet been completely successful, but he adds, with- 
out losing hope, ' I have not varied my experiments 
sufficiently to consider myself as beaten, and I am by no 
means discouraged.' 

Here the interesting documents relating to the early 
history of photography cease for a time ; no letter of 
Niepce's for the next nine years (18 17-1826) is to be 
found ; but it is certain that the illustrious and pains- 
taking inventor never abandoned his researches. In 1826 
we find him stopping definitely at balm of Judcea, a 
resinous substance which, when spread out thinly and 
exposed to the light, turns white and becomes in* 
soluble in essence of lavender. When placed at the 
focus of the camera a whitish delineation of the picture 



36 THE HISTORY OF PHOTOGRAPHY. 



thrown on to it is obtained. In possession of this fact, 
which he had so patiently conquered at the price of the 
most persevering researches, Niepce was enabled to re- 
produce engravings by the action of light and fix in a 
transient manner the image of the camera. 

As regards the first point, Niepce varnished the back 
of the engraving to be reproduced, thus rendering it trans- 
parent ; then he placed it on a tin plate which had pre- 
viously been covered with a thin coat of bitumen of 
Judaea. The transparent parts of the engraving, i.e. those 
which had not come in contact with the ink, allowed the 
light to pass through and whiten the bitumen of Judaea. 
A tolerably faithful copy of the engraving placed on it 
was thus obtained on the metal plate, which was then 
plunged into a bath of essence of lavender in order to 
dissolve those parts of the bitumen which had been pro- 
tected from the light. The picture thus obtained was 
permanent, the light having no further action on it. 

But this reproduction of engravings could only be 
considered as a scientific curiosity ; the grand problem 
was the fixing of the image of the camera. Niepce laid 
down the first plans for its solution. 

He placed at the focus of his camera a tin plate 
coated with bitumen of Judaea. The light whitened the 
resin wherever it fell on it, and rendered it insoluble in 



NICEPHORE NIEPCE. 37 

essence of lavender. The exposed plate was plunged 
into a bath of the fixing liquid, which dissolved only 
those parts of the bitumen not affected by the light ; a 
photograph was thus obtained in which the lights corre- 
sponded to the lights and the shadows to the shadows ; the 
former being produced by the whitened resin, the latter 
by the metal laid bare by the solvent. 

These metallic pictures, as may be supposed, were 
not of any great value ; they were feeble, pale, and dull. 
Niepce endeavoured to strengthen the tones by exposing 
the plate to vapours of iodine or sulphuret of potassium ; 
but his attempts were in vain. In his hands the new 
art of Heliography made no further progress ; the in- 
ventor, exhausted by ten years of labour, had done his 
part. 

Niepce's invention, important though it was, was but 
the germ of photography, and was subject to some 
grave defects. Bitumen of Judaea is a substance which 
is only acted upon very slowly and feebly by light. 
It was necessary to expose the metal plate in the 
camera for more than ten hours ; the sun displaced the 
lights and shades during this long space of time, the 
picture was therefore wanting in sharpness and definition. 

Niepce's chief aim was to apply his discovery to tho 
reproduction of engravings ; he succeeded in etching 



38 THE HISTORY OF PHOTOGRAPHY. 



with an acid those parts of his plates not protected 
by the resinous coating which had been rendered in- 
soluble by the action of the light, and was thus enabled 
to produce a plate for printing from as in the copper- 
plate press. He thus invented Heliography, and during 
his lifetime an artist named Lemaitre published some 
truly remarkable prints by this ingenious process. 

But the apparatus which Niepce had to work with 
was imperfect ; his cameras were roughly and badly 
made, his lenses were greatly inferior to those of the 
present day ; in spite of his fertile imagination, in spite 
of his unceasing toil, the boldness of his conceptions, and 
his indomitable perseverance, this great * working man ' of 
science could do no better with such poor tools. Niepce, 
we repeat, went no farther. Perhaps he did unwisely in 
abandoning the salts of silver which his predecessor 
had employed, perhaps he occupied himself too ex- 
clusively with the reproduction of drawings, but, how- 
ever it may have been, it is certain he had not the 
slightest idea of the developing agents^ i.e. the substances 
used at the present time for the purpose of making the 
latent picture, which has been mysteriously printed on 
the photographic plate, gradually appear. Some writers 
have, indeed, unjustly endeavoured to deprive Daguerre 
of the glory which is rightly his, as we shall see, in the in- 



NICEPHORE NIEPCE. 39 

vention of photography, in ascribing it solely to Niepce. 
Whilst recognising the latter as a great mind and ac- 
cording him all the marks of admiration which are his 
due, let us not separate his name from that of his 
future associate, Daguerre. The inventor of the Diorama 
would perhaps have done nothing without a predecessor, 
but he far surpassed the work of Niepce. If Daguerre 
did not conquer his America until another had pointed 
out the way he should follow, he had at least the glory 
of following to the very end this road bristling with 
barriers and impediments. 

The history of photography has been handled by 
some writers with regrettable prejudice ; their sincerity 
we are far from suspecting, but they have certainly 
allowed themselves to wander from the truth, pro- 
bably because, without sufficient scientific knowledge, 
they were incapable of rightly understanding even the 
principles of photography. To add to Niepce's fame 
they have tried entirely to suppress the name of Daguerre 
in the history of the art. We believe we are keeping 
within the bounds of strict impartiality in repeating 
that the names of Niepce and Daguerre should be placed 
together ; each of these great minds has had its part in 
the work we are studying. 



40 THE HISTORY OF PHOTOGRAPHY. 



CHAPTER IV. 

' THE NIEPCE-DAGUERRE PARTNERSHIP. 

CORRESPONDENCE EXCHANGED BETWEEN THE TWO INVENTORS— DIS- 
TRUST AND RESERVE OF NIEPCE — HIS JOURNEY TO PARIS — HIS 
INTERVIEWS WITH DAGUERRE — HIS JOURNEY TO LONDON — ACT OF 
PARTNERSHIP— DEATH OF NIEPCE. 

We have seen with what mistrust the first letter from 
Daguerre to Niepce was received by the latter. The 
inventor of the Diorama allowed almost a whole year to 
pass without giving further attention to the matter, but 
at the end of January 1827 he again wrote to Niepce, 
telling him explicitly that he was engaged in fixing the 
image of the camera, and that he had arrived at im- 
portant though very imperfect results. He solicited a 
mutual exchange of the secrets of which each was in 
possession. On receipt of this request, Niepce, without 
abandoning his prudent reserve, and after making en- 
quiries about Daguerre of Lemaitre (whom he had en- 
trusted with the working of his heliographic plates), and 
after receiving a favourable reply from that celebrated 
engraver, wrote as follows to the Parisian painter : — 



the niepce-daguerre partnership. 4i 

'Monsieur Daguerre, 

' I received yesterday your reply to my letter of the 
25th January, 1826. For the last four months I have 
been unable to work ; the bad weather entirely prevent- 
ing me. I have perfected in an important degree my 
process for engraving on metal, but the results obtained 
not having as yet furnished me with sufficiently correct 
proofs, I am unable to comply with your wish. This I 
regret more for myself than for you, Sir, as your process 
is very different, and promises you a degree of supe- 
riority of which engraving will not admit ; this, however, 
does not hinder me from wishing you all imaginable 
success.' 

It will be seen that Niepce, strong in his work, 
refuses as yet to disclose his secrets. This industrious 
and persevering genius knew the difficulties of the 
problem, and believed that no one was better able to 
solve them than himself. The compliments which he 
pays Daguerre evidently hide a little delicate irony under 
their prudent laconicism. 

But Daguerre would not be repulsed. Anxious to 
become acquainted with the processes of the experimenter 
of Chalons, he sent him a picture resembling a sepia 
drawing done by a process of his own. This fact is 



42 , THE HISTORY OF PHOTOGRAPHY. 

confirmed by a letter which M. Foque reproduces in his 
interesting historical work. 

* I forgot to tell you in my last letter,' writes Niepce 
to Lemaitre, the engraver, under date of April 3, 1827, 
* that M. Daguerre has written to me and sent me a little 
picture very elegantly framed, done d la sepia^ and 
finished by his process. This drawing which represents 
an interior, is very effective, but it is difficult to determine 
exactly what is the result of the process as the pencil 
has intervened. Perhaps you. Sir, are already acquainted 
with this kind of drawing, which the inventor calls 
smoked pictureSy and which are for sale at Alphonse 
Giroux's. 

* Whatever may have been Monsr. Daguerre's inten- 
tion, as one good turn deserves another, I have sent him 
a tin plate lightly etched by my process, choosing as the 
subject one of the engravings which you sent me. This 
communication cannot in any way compromise my 
discovery.' 

Shortly afterwards Daguerre received a little case 
from Chalons containing a tin plate engraved by Niepce's 
heliographic process. But the prudent Nicephore had 
taken care to wash the proof so thoroughly that not the 
slightest trace of the bitumen of Judaea was to be found 
on it. This engraving was, however, as Niepce himself 



THE NIEPCE-DAGUERRE PARTNERSHIP. 43 

says, very defective, and much too feeble. * I expect, 
Sir,' adds the inventor of hehography, * that you have 
followed up your former attempts ; you were succeeding 
too well not to go on ! We areoccupied with the same 
object, we should find an equal interest in our mutual 
efforts to attain the same end. I shall hear with much 
pleasure that the new experiment which you were to 
make with your improved camera has been successful as 
you expected. In that case, Sir, and if it is a fair offer, 
for my part I shall be as desirous of knowing the result 
as I shall be flattered to offer you such of my researches 
of a similar nature as I am occupied with.' 

It will be seen that the two inventors are being 
gradually drawn together by a bond of union. Here is 
Niepce making an offer to Daguerre ; he consents to 
give him his secrets in exchange for those which the 
latter may have to impart. 

But an event was about to occur which would bring 
these two geniuses together. In the month of August 
1827, Nicephore received intelligence that his brother 
Claude was seriously ill, and that his life was in danger. 
Nicephore, accompanied by his wife, started for England ; 
he had to pass through Paris, and being unexpectedly 
detained there some days, he took advantage of his 
stay in the capital to see Lemaitre and Daguerre. The 



44 



THE HISTORY OF PHOTOGRAPHY. 



details of his curious interview with the inventor of the 
Diorama are preserved to us in a very interesting letter, 
which we do not hesitate to reproduce entire. 



Fig. 5. 




t'j.y.o.r« 



JOSEPH NIEPCE. 



'I have had,' writes Niepce, on September 4, 1827, 
to his son Isidore, 'several long interviews with M. 
Daguerre. He came to see us yesterday, and stayed 
three hours ; we are to visit him again before we leave, 



THE NIEPCE-DAGUERRE PARTNERSHIP. 45 

and I don't know how long we may stay, as it will be 
for the last time, and we cannot find enough to say on 
the interesting subject of our interviews. 

* I can only repeat to you, my dear Isidore, what I 
said to M. de Champmartin. I have seen nothing here 
which has given me more pleasure than the Diorama. 
M. Daguerre himself conducted us there, and we were 
able to contemplate at our ease the most magnificent 
views. The view of the interior of St. Peter's, at 
Rome, by M. Bouton is certainly admirable and perfect 
in its illusion. But none are finer than the two scenes 
painted by M. Daguerre ; the one of Edinburgh by 
moonlight at the time of a fire ; the other of a Swiss 
village taken from the entrance of the main road and 
opposite a prodigious mountain, covered with eternal 
snows. These representations are so faithful even in the 
most insignificant details, that one seems to see wild and 
savage nature, with all the enchantment which is lent it 
from the charms of colour and the magic of light and 
shade. The illusion is even so complete that one is 
tempted to leave one's seat and cross the plain to 
clamber to the summit of the mountain. This I assure 
you is not the least exaggeration on my part. The objects 
either were or appeared to be of their natural size. They 
are painted on a canvas or taffeta covered with a 



46 THE HISTORY OF PHOTOGRAPHY. 

varnish having the drawback of sticking, which necessi- 
tates care when these species of decorations have to be 
rolled for transport, as it is difficult in unrolling to 
avoid tearing. 

* But to return to M. Daguerre. I told you, my dear 
Isidore, that he persists in thinking I am farther ad- 
vanced than he in the researches in which we are engaged. 
What is at least plain now is that his process and mine 
are totally different. His has something marvellous 
about it, and a celerity of action comparable to the 
electric fluid. M. Daguerre has succeeded in fixing on 
his chemical substance some of the colours of the solar 
spectrum ; he has already united four and hopes to 
obtain the other three, and thus to have the complete 
spectrum. But the difficulties he encounters increase 
in proportion to the modifications which the substance 
itself must undergo in order to be able to retain several 
colours at the same time ; a great hindrance, and one 
which foils him completely, is that totally opposite effects 
are produced by these combinations. Thus a blue glass, 
which produces a deeper shade on the said substance, 
produces a clearer tint than the part exposed to the 
direct action of light. Then again in this fixing of the 
primary colours the results obtained are so feeble that 
the fugitive tints are invisible in broad daylight ; they can 



THE NIEPCE-DAGUERRE PARTNERSHIP. 47 

only be seen in an obscure light, and for this reason : 
the substance in question is of the nature of Bolognese 
stone (sulphate of barytes) and pyrophorus ; it is very 
readily acted upon by light, but cannot retain the effect, 
because a somewhat prolonged exposure to the action of 
the sun ends by decomposition. M. Daguerre himself 
does not pretend to fix the coloured representations of 
objects by this process; even if he succeeds in surmount- 
ing all the obstacles in the way, he will only be able to 
make use of it as a sort of intermediary means. From 
what he has said to me, he seems to have little hope of 
succeeding, and his researches will hardly have any 
object but pure curiosity. My process appears to him 
to be certainly preferable, and much more satisfactory 
as regards the results which I have obtained. He is 
sensible how interesting it would be to obtain pictures by 
aid of a process equally simple, easy, and expeditious. 
He wishes that I should make some experiments with 
coloured glass in order to see if the impression pro- 
duced on my substance is the same as that on his. I 
shall procure five of these from Chevalier, who has 
already made them for M. Daguerre. The latter insists 
principally on rapidity of action in the fixation of the 
pictures ; a very essential condition indeed, and which 
must be the first object of my researches. As regards 



48 THE HISTORY OF PHOTOGRAPHY. 

the method of engraving on metal, he is far from de- 
preciating it ; but as it would be necessary to retouch 
and to deepen the impressions, he thinks that this process 
would succeed only very imperfectly for views. He 
thinks that for this sort of engraving the employment 
of glass and hydrofluoric acid would be much preferable. 
He is convinced that lithographic ink, carefully applied 
to the surface bitten by the acid, would produce on a 
white paper the effect of a good proof, and would more- 
over have a certain originality about it which would be still 
more attractive. The chemical composition employed by 
Daguerre is a very fine powder which does not adhere to 
the surface on which it is spread, and must therefore be 
kept horizontal. This powder on the least contact with 
light becomes so luminous that the camera is quite lit up 
by it. This substance, as far as I can remember, is very 
analogous to sulphate of baryta (cawk), or Bolognese 
stone, which also has the property of retaining certain 
prismatic rays. . . . 

* Our places are taken for Calais, and our departure 
is definitely fixed for next Saturday at eight in the morn- 
ing. We were unable to secure the places earlier, the 
King's journey to Paris having attracted many people in 
that direction. 

'Adieu — our best love to Jenny, yourself, and the 
youngster.' 



THE NIEPCE-DAGUERRE PARTNERSHIP. 49 

Nicdphore, on arriving in England, found his brother 
Claude dangerously ill, enfeebled by work, and his mind 
affected through over-study. He remained some weeks 
at Kew, and made the acquaintance of a distinguished 
Englishman, Sir Francis Baur, who undertook to lay the 
results of his heliographic researches before the Royal 
Society of London. But Niepce would not reveal his 
discoveries, and the learned English Society accepts no 
communication from an inventor who keeps his processes 
secret. 

Nicephore soon returned to Chalons and kept up a 
lively correspondence with Daguerre, ending by a pro- 
posal to enter into a partnership with him. After much 
hesitation and many delays,, the inventor of the Diorama 
at length visited Niepce at Chalons, and there they 
signed an agreement. 

In accordance with this agreement Niepce and 
Daguerre were mutually to acquaint each other with their 
processes. They were to work out and improve these 
processes in common, and together attain the object of 
their labours, viz., the fixation of the image of the tamera. 
The company thus formed was to go by the name of the 
Niepce-Daguerre ; its place of business was at Paris ; and 
the proceeds of working the new discovery were to be 
divided between the two partners. 



50 THE HISTORY OF PHOTOGRAPHY. 



After signing this agreement Niepce acquainted 
Daguerre with the processes which he employed in pre- 
paring his heh'ographic plates. Feeble indeed was the 
result, as we have already seen. But the inventor of the 
Diorama had even less to give for the little he received. 
He returned to Paris after seeing Niepce's apparatus in 
action, resolved to work without ceasing until success 
crowned his efforts. 

' Suddenly,' says Charles Chevalier, * Daguerre be- 
came invisible. Shut up in a laboratory which he had 
had constructed in the Diorama building, where he 
resided, he set to work with fresh ardour, studied 
chemistry, and for nearly two years lived almost con- 
tinuously in the midst of books, assay crucibles, retorts, 
and melting pots. I have caught a glimpse of this 
mysterious laboratory, but neither I nor anyone else was 
ever allowed to enter it. Madame Daguerre, Messrs. 
Bonton, Sebon, Carpentier, etc. can bear witness to the 
truth of these recollections.' ' 

In the midst of his researches and experiments, 
Daguerre was at last favoured with one of those accidents 
which often happen to the persevering worker. He had 
left a silver spoon on a metal plate which had been 

* Guide du Photographe {^Souvenirs Historiques). 



THE NIEPCE-DAGUERRE PARTNERSHIP. 5 1 

treated with iodine, what was his surprise to find on lift- 
ing the spoon that its image was clearly and sharply 
imprinted on the iodised surface ! 

This observation was a precious revelation to 
Daguerre. He abandoned the bitumen of Judaea, and 
substituted for it iodide of silver, which darkens with 
wonderful rapidity under the action of light. To make his 
preparation, he exposed a silvered plate to the influence 
of vapours of iodine, and he thus obtained a surface 
which impressed itself with the picture thrown on it by 
the lens of the camera. But the plate only presented a 
faint shadowy image of the picture which existed still in 
a latent state ; after trying numberless chemical sub- 
stances and agents of every description, Daguerre at 
last discovered that petroleum oil possessed the property 
of developing the image on his plate. This discovery 
was a great step towards success ; Daguerre had put his 
hand on a developing agent. He did not rest con- 
tent here, but went on unceasingly, and at last substituted 
for petroleum oil the vapours of mercury, causing the in- 
visible image which the light had printed on the iodised 
silver .plate, to appear as if by magic and with mar- 
vellous distinctness. 

Photography was henceforth a fact. Daguerre had 
not failed to write to his partner : he told him of his 



52 THE HISTORY OF PHOTOGRAPHY. 

having made use of iodide of silver, but Niepce did not 
believe in the efficacy of this substance. Before learning 
the almost definite results which Daguerre had obtained, 
he was seized with congestion of the brain and died 
July 5, 1833. 



53 



CHAPTER V. 

THE DAGUERREOTYPE. 

DAGUERRE'S researches and studies — HE CEDES HIS INVENTION TO 
THE STATE— ARAGO AND THE DAWN OF PHOTOGRAPHY— A BILL 
LAID BEFORE THE HOUSE— REASONS FOR ITS BEING PASSED — MEET- 
ING OF THE ACADEMY OF SCIENCES, AUGUST ID, 1839, 

Daguerre is thus left alone to solve the problem — a 
task which, in spite of its many difficulties, he had 
determined to accomplish. The ingenious artist has 
discovered a fact full of promise ; he has seen that the 
image, traced so to speak in a latent state by the light 
on a plate coated with iodised silver, gradually reveals 
itself, that is to say becomes visible and manifest, when 
exposed to the action of vapour of mercury. The in- 
ventor held in his hand the thread which would conduct 
him in the labyrinth of his enquiries ; he was no longer 
working in the dark, for he was in possession of the guide 
which would lead him to the light. 

But the days and months passed in continual labours, 
and it was only at the price of two years entirely devoted to 



54 THE HISTORY OF PHOTOGRAPHY. 

toil that Daguerre at last perfected the beautiful art 
which was to immortalise his name. 

In 1835, Daguerre was in a position to acquaint 
Isidore Niepce, son of Nicephore, with the improvements 
which he had effected. It was time to publish the dis- 
covery of heliography. An additional clause was added 
to the before-mentioned agreement. Two more years 
were passed in constant toil and study. At length in 
1837, Daguerre and Isidore Niepce signed a regular act 
of partnership and endeavoured to start a company to 
work the new discovery. 

On March 15, 1838, the subscription was opened ; but 
the incredulous public did not respond to the call ; funds 
were not forthcoming ; capitalists seemed to run away 
from the new art of photography.^ 

^ To give a true idea of the impression which the appearance of the 
Daguerreotype produced, we give almost entire an article which appeared 
in the Moniteiir [/niversel of ]anvia.ry 14, 1839; at this time, the results 
obtained by Daguerre were already known, and were the universal theme 
in all the papers. 

'The discovery of M. Daguerre,' says the writer of the article, 'has been 

for some time past a subject of some wonderful accounts After 

fourteen years of research M. Daguerre has succeeded in fixing the natural 
light on a solid surface, in giving a body to the impalpable and fugitive 
image of objects reflected in the retina of the eye, in a mirror, in the 
apparatus of the camera obscura. Figure to yourself a glass which after 
receiving your image presents you your portrait, as indelible as painting, 
and much more faithful. 

' What is the inventor's secret ? What is the substance endowed with 
such astonishing sensibility as not only to become penetrated with light, but 



THE DAGUERREOTYPE. 55 

Daguerre then decided to cede his invention to the 
State. He addressed himself to several men of science 
and knocked at Arago's door. The illustrious astronomer 
and man of science was thunderstruck at first sight of 
the Daguerreotype plate, and was boundless in his ex- 
pressions of admiration. The inventor had found his 



also to retain the impression, thus operating at the same time like the eye 
and like the optical nerve, like the material instrument of the sensation and 
like the sensation itself? Indeed we cannot say. M. Arago and M. Biot, 
who have read reports on the effects of M. Daguerre' s discovery, have 
declined to define their causes. By the courtesy of the inventor we have 
been able to examine his chefs-d^ auvre^ in which Nature herself is drawn. 

* Each picture placed before us called forth some admiring exclamation. 
What fineness of touch ! what harmony of light and shade ! what delicacy ! 
what finish \ . . , . With a magnifying glass we can see the slightest fold 
in a stuff, the lines of a landscape invisible to the naked eye, .... In a 
view of Paris we can count the paving stones — we see the dampness pro- 
duced by rain ; we can read the name on a shop. All the threads of the 
luminous tissue have passed from the object into the image.' 

A little further on the writer indulges in a singular supposition : — 

* M, Daguerre,' he says, ' has as yet only made experiments at Paris, and 
these experiments, even under the most favourable circumstances, have 
always taken so much time as only to enable him to obtain complete results 
of nature inanimate or at rest, movement escapes him or only leaves vague 
and indefinite traces. It is presumable that an Afi-ican sun would give him 
instantaneous autographs of nature in action and in life.' 

The author concludes with more sensible remarks: — 'The discovery, 
as far as at present developed, to judge from the results which we have 
seen, promises to be of great importance to art and science. Some persons 
seem to be afraid that it will leave nothing for draughtsmen, and perhaps 
even for painters, to do. It seems to us that it can only prove prejudicial to 
the copyist. We have never heard that the invention of moulding on nature 
has put the genius of the sculptor in the shade. The discovery of printing 
did serious injury to the scribes, but not to the writers.' 



$6 THE HISTORY OF PHOTOGRAPHY. 

advocate. Arago sent him to Duchatel, the then Home 
Minister, who offered Daguerre and Isidore Niepce Hfe 
pensions (modest enough ! ) in exchange for their secrets. 

On June 15, 1839, Duchatel laid before the House a 
bill relating to the new discovery, preceded by the fol- 
lowing reasons for its acceptance : — 

' You all know, and some among you have already 
been able to prove for yourselves, that after fifteen years 
of persevering and costly research, M. Daguerre has suc- 
ceeded in fixing the image of the camera, and of thus 
creating, in four or five minutes by the aid of light, 
drawings in which the objects preserve their forms, even 
to the slightest detail, in which linear perspective and the 
degradation of tone produced by aerial perspective are 
reproduced with a delicacy hitherto unknown. 

' It is not necessary to dwell upon the utility of such 
an invention. It will easily be understood what new 
facilities it must offer for the study of the sciences ; and 
as to the arts, the services it can render to them are 
incalculable. 

' These reproductions so true to nature would be a 
constant object of study to artists and painters, even the 
most talented ; and on the other hand, this process offers 
them a ready and easy means of forming collections of 
studies which, if they made themselves, they could only 



THE DAGUERREOTYPE. 57 

obtain at the cost of much time and labour and in a much 
less perfect manner, 

' The art of the engraver would take a new degree of 
interest and importance, when employed to reproduce 
and multiply these pictures drawn by Nature herself 

' Finally, to the traveller, to the archaeologist, as well 
as the naturalist, the apparatus of M. Daguerre would 
become a continual and indispensable necessity. It will 
enable them to fix their impressions without having re- 
course to the hand of a stranger. Every author would 
become his own illustrator ; he would halt a few seconds 
before the most extensive view, and obtain on the spot 
an exact facsimile of it. 

* Unfortunately for the inventors of this beautiful 
discover}'-, they find it impossible to make a matter of 
business of it, and to indemnify themselves for the sacri- 
fices which were necessitated by such numerous attempts 
so long fruitless. 

* Their invention is not one which can be protected 
by a patent. As soon as it is known, anyone can make 
use of it. The most awkward person will be able to 
make pictures as exact as a practised artist. It thus 
follows that this process must belong to all the world or 
remain unknown. And what just regrets would not be 
expressed by all the lovers of art and science if such a 



58 THE HISTORY OF PHOTOGRAPHY. 

secret remains impenetrable to the public, if it must be 
lost and die with the inventors ! 

' In such an exceptional circumstance it behoved the 
Government to intervene. It is for it to put society in 
possession of the discovery which it demands to enjoy in 
the general interest by giving to its authors the price, or 
rather the recompense, of their invention. 

* These are the motives which have led us to conclude 
a provisional agreement with Messrs. Daguerre and 
Niepce, for which the object of the bill we have the 
honour to lay before you is to ask your sanction. 

* Before acquainting you with the bases of this treaty, 
it will be necessary to give a few more details. 

* The possibility of transiently fixing the image of 
the dark room has been known for the last century ; but 
this discovery promised no useful results ; the substance 
on which the solar rays pictured the image had not the 
property of retaining it, and became completely black as 
soon as exposed to the light of day. 

' M. Nicephore Niepce invented a means of render- 
ing these pictures permanent. But, although he had 
solved this difficult problem, his invention still remained 
very imperfect. He could obtain only the outline of 
objects, and he required at, least twelve hours to obtain 
the slightest drawing. 



THE DAGUERREOTYPE. 



59 



' It was by totally different means, and by putting 
aside the traditions of M. Niepce, that M. Daguerre has 
been able to arrive at the admirable results which we 



Fig. 6. 




DAGUERKE. 



have witnessed, namely, the extreme rapidity of the ope- 
ration, the reproduction of aerial perspective, and all the 
play of light and shade. M. Daguerre's method is his 
own ; it belongs to him alone, and is distinguished from 



6o THE HISTORY OF PHOTOGRAPHY. 

that of his predecessor as much in its cause as in its 
effects. 

'At the same time, as before the death of M. N. 
Niepce an agreement was made between him and M. 
Daguerre, by which they engaged to share mutually all 
the advantages they might receive from their discoveries, 
and as this stipulation has been extended to M. Isidore 
Niepce, it is impossible to treat alone with M. Daguerre, 
even respecting the process which he has not only per- 
fected but invented. It must not be forgotten, moreover, 
that M. Niepce's invention, although it is still im- 
perfect, is perhaps susceptible of being improved and of 
being employed usefully under certain circumstances ; it 
is therefore of importance to history and science that it 
should be published at the same time as that of M. 
Daguerre. 

' These explanations will show you, Gentlemen, for 
what reason and by what title Messrs. Daguerre and 
Isidore Niepce are made parties in the agreement which 
you will find annexed to the bill.' 

After reading this document, which, believing im- 
partiality cannot be too strictly adhered to in history, 
we have thought it our duty to reproduce entire, the 
Home Minister read the bill which assigned a life pension 
of 6,000 francs a year to M. Daguerre, and to Isidore 



THE DAGUERREOTYPE. 6 1 

Niepce a life pension of 4,000 francs a year, the half of 
each pension being reversionary to the widows of 
Daguerre and Niepce. 

One is astounded at the smallness of the sums ac- 
corded in exchange for one of the grandest of modern 
inventions, the importance of which was well understood, 
and from which there was no doubt great results would 
be obtained. It is true something was added to the 
value of these pensions by ornamenting them with the 
name of National Reward. But if the Government was 
thus careful of the public money, the nation at least 
was lavish in bestowing on Daguerre the marks of its 
great enthusiasm and admiration,^ 

The bill was passed with acclamation by the House 
and also by the House of Peers. Arago, as perpetual 
secretary of the Academy of Sciences, was charged to 

' In oui- historical account we have rendered to Daguerre the glory 
which is due to him in the invention of photography, A distinguished 
writer, who has done us the honour to notice our work in the press, has 
accused us of partiality in saying that Nicephore Niepce was the real dis- 
coverer of the art in question, Daguerre has been violently attacked by a son 
of Nicephore, dispossessed of his titles by M, Victor Fouque, a critic, 
evidently sincere, but whose ignorance in the matter of chemical reagents 
has drawn him aside from the truth. We have endeavoured to judge imparti- 
ally the old disputes which have been brought forward, and we make bold to 
say that we have retraced the facts in the light in which they ought to be 
studied. Is it necessary to add that in our work the researches of the 
illustrious inventor of the Daguerreotype have been estimated by the light 
of historical documents, that is to say without any preconceived ideas ? 



62 THE HISTORY OF PHOTOGRAPHY. 

communicate to that learned society the description of 
the Daguerreotype process. This was the name by 
which the marvellous discovery was to be henceforth 
known. 

August 10, 1839, was the day fixed, and crowds 
of people curious to hear the secret thronged the ap- 
proaches to the Institut. On this exceptional occasion 
the Academy of the Fine Arts had assembled at the 
Academy of Sciences. The seats reserved for the 
public were filled with those whom Paris counted her 
most eminent men. Every eye was fixed upon Da- 
guerre, who, in his modesty, shunned the public gaze, 
and seemed to wish to divest himself of a triumph 
which the great Arago had taken under his special care. 
It would not be necessary to know the Parisian 
public, so eminently impressionable and easily excited, 
to ask if the approaches to the Institut were crowded 
with people. All that Paris contained in the shape of 
artists, of young students, and inquisitive persons were 
to be found at the doors of the Mazarin Palace. Arago 
had spoken ; his words were repeated by a hundred 
mouths, they circulated in the corridors, they burst forth 
on the quays, where comments flew about more or less 
explicit. * It is the iodide of silver and mercury,' cried one 
person.' * No,' said another, ' it is the bitumen of Judaea.' 



THE DAGUERREOTYPE. 63 

* It is nitrate of silver, I tell you,' replied a third. Such 
exclamations as these were bandied about, but none 
had understood anything about Daguerre's secret. 

Meanwhile the time passed, the papers appeared 
containing accounts of the solemn sitting of the 
Academy ; they explained more clearly the Daguerreo- 
type process. The opticians made experiments and ex- 
posed cameras and the necessary apparatus for taking 
Daguerreotypes in their shop-windows ; these were at 
once pounced upon and disputed for by everybody who 
could afford to buy them, and all Paris had caught the 
Daguerreotype fever. The artists were seized with 
astonishment and admiration : Paul Delaroche sought 
out Daguerre, obtained a Daguerreotype plate from 
him and showed it everywhere, exclaiming — ' Painting is 
dead from this day !' 

The art of Raphael and Michael Angelo was not 
killed ; on the contrary, it was to find new resources in 
the inspirations of a great inventor, and Science was 
about to give her hand to Art ! 



64 THE HISTORY OF PHOTOGRAPHY. 



CHAPTER VL ^ 

THE PROGRESS OF A NEW ART. 

THE DAGUERREOTYPE PROCESS — ACCELERATING SUBSTANCES— IMPROVED 
LENSES— PORTRAITS— FIXING AGENTS —DISCOVERY OF PHOTOGRAPHY 
ON PAPER BY TALBOT — M. BLANQUART-EVRARD. 

Soon after the memorable sitting of August lo, the 
processes of Daguerre were known to all Paris, all 
France, and one may even say, for so rapid was the 
success of the new art, to the entire civilised world. 

All over the capital cameras were to be seen, 
perched on the balconies of houses, on the boulevards, 
before the monuments, everywhere. But these newly- 
improvised photographers obtained for the most part but 
poor results ; the pictures they sought to fix in their 
cameras were generally indistinct, and showing perhaps 
but a few secondary objects of the coveted view. The 
method was simple and precise, but it required, never- 
theless, a certain amount of practice in its delicate 
manipulations, and it required some time even for a good 
operator to make it profitable. 



THE PROGRESS OF A NEW ART. 65 

The photographic images obtained by the henceforth 
illustrious inventor of the Diorama were formed on the 
surface of a plate of silvered copper. The first opera- 
tion was to iodise the silver. The silvered plate had to 
be perfectly polished and clean. First of all it had to 
be rubbed with a pad, or buff polisher (fig. 7), in order 
to give it the utmost possible brilliancy, and to remove 
from its surface the slightest trace of any foreign 
particles which might have got attached to it. 

Fiff. 7- 




DAGl'ERREOTYPE POLISHER. 



The silvered plate thus prepared was placed in the 
iodising box, in which it was supported by a frame over 
crystals of iodine. 

The fumes of iodine act on the silver, combine with 
it, and form a yellow coating of iodide of silver. 

The plate thus sensitised is then exposed in the 
camera, where it receives the image projected on to the 
prepared surface at the focus of the lens. The rays of 
light which form the image decompose the iodide of 

F 



66 



THE HISTORY OF PHOTOGRAPHY. 



silver just in proportion to their intensity, the parts ex- 
posed to the high Hghts of the picture undergoing the 
greatest change, while in the shadows the iodised surface 
remains unaltered. The most curious feature in this 



Fig. 8. 




MERCURIAL DEVELOPING BOX. 



preliminary stage of the process is, that the plate when 
removed from the camera presents no visible signs of 
chemical change, although there is a latent image caught 
in the most delicate beauty of light and shadow upon its 
surface. In order to render this image visible it is neces- 



THE PROGRESS OF A NEW ART. 6") 

sary to submit the plate to the operation of develop- 
ment, by placing it in a box above a bath of mercury gently 
heated to a temperature of about 50° Reaumur, ascer- 
tained by a thermometer. (See fig. 8.) The mercury 
emits fumes which, coming in contact with the prepared 
surface, have a liking for and condense upon the parts 
decomposed by the light, while the shadows protected by 
unaltered iodide of silver are shielded from the attack of 
this subtle developing agent. Thus gradually, as if by 
magic, the mysterious plate reproduces every detail of 
the scene before which the camera has been placed. 

After the picture has been developed it becomes 
necessary to fix it, as, still susceptible to the influence of 
light, it would soon be blotted from the surface of the 
plate. In order then to remove the unaltered iodide of 
silver it is immersed in a solution of hyposulphite of 
soda,^ which clears the shadows and leaves the lights and 
half-tones of the image intact. 

The Daguerreotype image is thus fixed and is formed, 
as we have seen of a delicate coating of mercury ; this 
metal, spread over the silvered surface, appears brilliant in 
the lights, whilst in the shadows it has not taken hold ; 

' The use of hyposulphite of soda as a photographic developing agent 
was made known in a paper by Sir John Herschel, published soon after the 
invention of the Daguerreotype process. — Ed, 

F 2 



6S THE HISTORY OF PHOTOGRAPHY. 

the latter are represented by the polished surface of the 
metal plate, where the developer has laid it bare. But 
the picture thus obtained offered several grave drawbacks. 
Its mirror-like nature was one of the worst : in order 
to see the picture as fixed on the plate, it was necessary 
to hold it at a certain angle to the light, and it often 
appeared to have more of the properties of a mirror 
or stained tin plate than of an artistic drawing. 

In Daguerre's time the exposure in the camera had 
to be prolonged for at least fifteen minutes ; consequently 
to dream of taking portraits Avas out of the question; 
whilst if a landscape was attempted, the masses of 
verdure were represented by white silhouettes or monoto- 
nous blots.^ 

Besides these inconveniences, the Daguerreotype 
would not resist the slightest touch ; a finger passed over 
it destroyed the whole picture ; moreover, it did not long 
remain intact, a short time sufficed to deprive it of its 
sharpness. 

These difficulties were, however, overcome. A 
method of protecting the Daguerreotype picture by a pro- 
cess called gilding was discovered. This process consists 
in imparting a hardness to the coated surface by means 

• The process was subsequently accelerated and rendered available for 
portraiture by Goddard's discovery of the rapid action of bromine.— Ed. 



THE PROGRESS OF A NEW ART. 



69 



of a liquid containing gold in solution. Hyposulphite 
of gold and soda give excellent results. 

This salt is dissolved in a large quantity of water, the 
Daguerreotype plate is immersed in this solution,and then 
gently heated over a spirit lamp, as shown in fig. 9. 




GILDING THE DAGUEKKEOTVPE PLATE, 



It is a fact in chemistry that one oxidable metal will 
displace another less easily oxidable ; for this reason, the 
mercury is dissolved and replaced by the gold on the 
silvered surface. As may be supposed, after this substi- 



70 THE HISTORY OF PHOTOGRAPHY. 

tution of gold for mercury, the picture has assumed a 
different aspect, but it has gained notably by the ex- 
change ; it has acquired vigour, and become more pleas- 
ing in appearance, and, most important of all, is capable 
of resisting moderate rubbing. When the gilding is 
completed, the plate, after being well washed to remove 
the excess of salt is then dried, and finished. 

As soon as Daguerre's invention was known, a great 
number of artists and men of science applied themselves 
to the practice and improvement of it. It will be readily 
understood that an essential improvement consisted in 
diminishing the time of exposure in the camera. To 
arrive at this result, it was above all necessary to alter 
the lens which produced the pictures. Daguerre 
had given rules which fixed the dimensions of the lens 
according to the different sizes of silvered plates 
used. But these observations of the clever experimen- 
talist referred specially to the reproduction of general 
views of landscapes or objects at a distance. From all 
parts came anxious enquiries as to whether the Daguerreo- 
type would not produce portraits ; and whether, as a 
writer of the time says, the prodigy accomplished in a 
story of Hoffmann was not soon to be realised, and, to 
quote the words of the author of the ' Contes fantas- 



THE PROGRESS OF A NEW ART. 7 1 

tiques,' ' the lover would present his mistress with a mirror 
in which she would see his image.' 

To solve this problem it was indispensable that the 
focus of the lens should be shortened, and a greater quan- 
tity of light condensed on the plate in order to illumi- 
nate more vigorously, and thus more rapidly impress 
the sensitised surface. Charles Chevalier constructed 
a camera with two achromatised object-glasses, which 
gave a very sharp and brilliantly lighted image. ^ 
With this improvement the time of exposure was reduced 
to a few minutes. 

' However,' says M. L. Figuier in his excellent essay 
on photography, * this most important problem of lessen- 
ing the exposure to the light was not completely solved 
till 1 84 1, and then, thanks to a discovery of great value. 
Claudet, a French artist, who had bought of Daguerre 
the exclusive right to introduce the photographic pro- 
cesses in England, discovered the properties of accelerat- 
ing substances.* 

In photography the name accelerator is given to 
certain substances which, when applied to a plate 
previously iodised, increase in an extraordinary degree 

' The double combination achromatic portrait lens was invented by Prof. 
Petzral of Vienna, and brought to a high degree of perfection by M. 
Voglander, whose lenses, some twenty years ago, were eagerly sought after, 
and are prized by photographers at the present day. — Ed. 



72 THE HISTORY OF PHOTOGRAPHY. 

its sensitiveness to light. Alone, these substances are 
non-photogenic J that is to say they are not in themselves 
capable of producing a combination which would be 
chemically influenced by light, but if applied to a plate 
already iodised they give it the property of receiving the 
impress of an object in a few seconds. 

The substances capable of thus stimulating the 
iodised silver are numerous. The first, introduced by 
Claudet, is chloride of iodine ; but it yields considerably 
in sensibility to substances which were afterwards dis- 
covered. The fumes of bromine, bromide of iodine, 
bromide of lime, chloride of sulphur, bromoform, 
chloric acid, Hungarian liquid, Resier's liquid, and 
Thierry's liquid, are the quickest-acting accelerators: 
with chloric acid perfect pictures have been obtained in 
half a second. 

By the discovery of these accelerating substances 
Daguerreotypes could now be taken of animate objects, 
and thus the long-desired portraits were at length attain- 
able. Already in 1840, attempts had been made to 
obtain portraits with the Daguerreotype ; but the long 
exposure necessarily rendered them fruitless. These 
attempts were made with the long-focus lens, which only 
admitted a light of feeble intensity into the camera ; it 
was also necessary to place the person in full sun-light. 



THE PROGRESS OF A NEW ART. 73 

and prolong the exposure for a quarter of an hour As 
it is impossible to keep the eyes open so long a time to 
the effect of the solar rays, the sitter was obliged to 
close them. Many bold amateurs made martyrs of 
themselves in this way, but the result was not what their 
courage merited. In 1840 at Lusset's shop in the Place 
de la Bourse, might have been seen a row of sad 
Belisaires, labelled ' photographic portraits ' ! ^ 

The invention of short -focus object-glasses allowed — 
in the execution of portraits — the torment of the patient 
condemned to absolute immobility to be reduced to 
four or five minutes. But it was still necessary to sit in 
full sun-light. The model took a graceful attitude, rest- 
ing one hand on the back of a chair, and looking as 
amiable as possible. But the sun fell full in his eyes ! 
The operator gives the final warning to keep perfectly 
still ! The seconds pass, succeed each other, and seem 
to expand into centuries ; the sitter, in spite of all his 
efforts, is overpowered by the solar rays, the eyelids 
open and close, his face contracts, the immobility to 
which he is constrained becomes a torture. His features 
shrivel up, tears fall from his eyes, perspiration beads on 
his forehead, he pants for breath, his entire body shakes 
like that of an epileptic who wants to keep still, and the 

L. FiguUr^ les Merveilles de la Science. 



74 THE HISTORY OF PHOTOGRAPHY. 

Daguerreotype plate represents the image of a poor 
wretch undergoing all the tortures of the ordeal by fire. 
Shortly afterwards the discovery of the accelerating sub- 
stances permitted Daguerreotype portraits to be taken 
with something of artistic feeling. 

It is not our purpose to describe minutely the dif- 
ferent Daguerreotype operations, and the various im- 
provements effected ; we shall content ourselves with 
noticing only the discoveries made by M. Fizeau, a 
French experimentalist. This clever operator discovered 
the means of fixing the Daguerreotype picture by cover- 
ing it with a slight coating of gold. He arrived at this 
result, as we have seen, by pouring a solution of chloride 
of gold and hyposulphite of soda on to the plate and then 
gently heating it. With this discovery the complement 
of the processes used in photography was completed ; the 
image of the camera fixed in a latent state on a sensi- 
tive substance was made to appear by developing 
agents, the time of exposure was lessened, and the 
picture could, by the action of chemical agents, be fixed, 
that is to say, rendered indelible. 

Soon, other new discoveries were to transform, in 
every way, the art of Daguerre ; but the illustrious in- 
ventor had not the consolation of knowing them. He 
died on July lo, 1851, foreseeing in his thoughts the new 



THE PROGRESS OF A NEW ART. 75 

horizons to the conquest of which the wondrous art he 
had created was rapidly marching. 

Whilst Daguerre was carrying on his researches in 
France, in 1834 Mr. Talbot in England was also en- 
deavouring to fix the image of the camera ; but his aim 
was to fix it on paper.' 

This modest and almost unknown inventor subjected 
a sheet of paper, which had been soaked in iodised silver, 
to the action of light in the camera ; and he developed 
the picture, formed as in the Daguerreotype, in a latent 
state, with gallic acid. The employment of this sub- 
stance was another great help to photography. 

Talbot was in the midst of his researches when he 
heard of the publication of Daguerre's invention. He 



' The English have claimed, but wrongfully, the merit of the invention 
of photography. Talbot's method was not practicable. If Talbot kept 
silence before Daguerre had published his discovery, it was because he was 
aware of the imperfections in his method. Before offering it to the public 
he desired to give it the certainty and facility of working which it arrived 
at in the hands of Blanquart-Evrard. The publication of the results 
obtained by Niepce and Daguerre established their titles as inventors of 
photography. 

(While I am at one with the author in according to Daguerre the full 
credit of the beautiful invention which bears his name, yet the claims of 
Talbot can hardly with justice be relegated to a position inferior to that of 
the famous French inventor. Talbot in 1834, about five years before 
Daguerre's method was made known to the world, had solved for himself 
•the problem of fixing the photographic image on paper. See Abridgment 
of Specifications, printed by order of the Commissioners of Patents in 
England, 1854.— Ed.) 



76 THE HISTORY OF PHOTOGRAPHY. , • 

sent the results of his experiments to France, to Biot, 
who brought them before the Academy of Sciences. But 
the Daguerreotype seemed to have the sole right to 
occupy the attention of Paris ; people got tired of the 
numberless * improvements ' which were continually 
announced, for the most part merely the empty dreams 
of excited and inexperienced minds. Talbot's discovery 
had not the good fortune to attract the attention of the 
learned world. It was, however, estimated at its true 
value by a laborious spirit, Blanquart-Evrard, who cleverly 
profited by the facts made known by the experimentalist 
across the Channel, and who soon brought out an 
interesting memoir of photography on paper. Such a 
result was anxiously waited for; it was generally ac- 
knowledged that the mirror-like character of the 
Daguerreotype plate was incompatible with a really 
artistic picture ; it was thought with reason that a proof 
on paper would be softer and would resemble a sepia 
drawing. Thus, as soon as Blanquart-Evrard of Lille 
published his method, his communications were received 
with expressions of joy by all photographic amateurs. 

Blanquart-Evrard plunged his paper in a sensitising 
solution ; when it was dry he fastened it between two 
pieces of glass and so exposed it in the camera. These 
tiQw manipulations, it must be admitted, were almost 



THE PROGRESS OF A NEW ART. 77 

exactly similar to those employed by Talbot. The latter 
made use of iodised silver as a sensitising agent for pro- 
curing a positive proof on paper ; he employed chloride 
of silver on the negative paper, and fixed the picture by 
means of gallic acid.^ He had the first idea of making 
a negative picture to be used in the production 
of positive proofs ; he must be considered as the inventor 
of proofs on paper, and his name ought to be inscribed 
in the annals of photography directly after those 
of Niepce and Daguerre. 

Blanquart-lEvrard, profiting by the interesting studies 
of Talbot, contributed to the improvement of the photo- 
graphic art ; he studied it wholly from an artistic point 
of view ; he asked himself what were the rules which 
should be observed in order to obtain pictures possessing 
true harmony and worthy of being considered by a 
painter. He found out ingenious methods of gfving force 
to the shadows, and of colouring the positive proof, and 
that by mixing certain chemical substances with the re- 
agents already in use. 

Blanquart at length was able to produce thirty or 

' Amongst those who from its origin have contributed to popularise 
photography must be mentioned Bazard, who after patient researches suc- 
ceeded in producing some, for his time, remarkable photographic proofs. 
They were exhibited to the students of the Sorbonne University of Paris 
by M. Despretz in 1846. 



78 



THE HISTORY OF PHOTOGRAPHY. 



forty positives from a negative, whilst before, two or 
three were the utmost that had been obtained. It would 
be ungrateful to omit his name in the history of the 
photographic art.^ 

' See for further details on this subject the Treatise on Photography on 
Paper, by Blanquart-Evrard (of Lille), Paris, 1851. 



A list of some of the processes which the publication of the discoveries 
of Daguerre & Talbot gave rise to is here given. Being quite out of date 
and superseded by processes subsequently discovered, a detailed description 
is unnecessary. 

A?7iphitype. A paper process proposed by Sir John Herschel. 

Anthotype 

Calotype 

Chromatype 

Chrysotype 

Cyanotype 

Energiatype ,, ,, ,, Mr. Hunt. 

In another process for producing instantaneous views, galvanism was ap- 
plied, the sensitised plate being under the influence of the fluid when 
exposed. 



invented and perfected by Mr. Talbot, 
in which chromatic acid was used, 
discovered by Sir John Herschel. 



79 



CHAPTER VII. 

PHOTOGRAPHY. 

SIR JOHN HERSCHEL — HYPOSULPHITE OF SODA — NIEPCE DE SAINT- 
VICTOR'S negative on glass — GUN COTTON AND COLLODION. 

It is a remarkable fact in the history of great discoveries 
that the inventor himself is rarely able to give those 
finishing touches and improvements to the results of his 
genius which time and practice are sure to develop in 
them. The mind of the inventor, however ingenious he 
may be, creates only slowly and painfully. How often 
has it not been the case that after supplying some new 
materials to the edifice of science, the inventor seems to 
exhaust himself, and has had to give up his task to other 
hands ! Many examples might be quoted in proof of 
this. Fulton, for instance, started to the conquest of the 
seas on a steamboat, rude and primitive enough : with 
this first effort his mind seemed to have exhausted itself ; 
one might say that his faculties had not the gift of pro- 
ducing ; they had invented this novelty, they were in- 



8o THE HISTORY OF PHOTOGRAPHY. 

capable of promoting its growth ; it was reserved for 
others to give it the development of ripe age. Daguerre, 
after fifteen years of toil, gave the world the Daguerreo- 
type plate, the first rudiment of photography ; but here 
he stops, his genius can carry him no further. 

But the seed sown on the field of discoveries is culti- 
vated by other eminent minds, whose labours ensure the 
fruits of harvest. By the side of the inventor appear a 
crowd of those who, whilst capable of improving, are 
often incapable of inventing. The history of photography 
is a remarkable example of this. Fizeau, Chevalier, 
Talbot, Blanquart, have added their stones to the monu- 
ment which was founded by Niepce and Daguerre ; other 
great workers arrived from time to time to contribute 
their valuable aid to the work of building ; the monu- 
ment grows more magnificent and grand as the years 
pass on. 

The new discovery had excited the admiration of all ; 
thQ attention of the whole world was drawn to it. Here 
is the great Herschel, the illustrious English astronomer, 
taking photographic proofs ; the attention of such a 
mind could not be directed to the Daguerreotype without 
exerting a salutary influence on it. He fixed the image 
on paper by the method of which he had read the 
description ; the idea occurred to him of substituting 



PHOTOGRAPHY. 8 1 



hyposulphite of soda for the agents until then employed. 
He succeeded beyond all expectation, and from that day 
the hyposulphite of soda has been counted amongst 
the most valuable substances of the photographic 
laboratory. 

As soon as Blanquart-Evrard had published his pro- 
cess of photography on paper, it was immediately tried 
by everybody, and the use of the silvered plate aban- 
doned. This last, it must be owned, certainly offered 
the advantage of being practical and of producing very 
clear, sharp pictures, with extreme fineness of execution 
in the details ; it gave proofs of great delicacy of feature 
and matchless softness. But with paper, no more mirror- 
like reflection, no more of those metallic gleams which 
only permitted the picture to be seen after inclining it in 
every direction towards the light. 

But everything has its good and its bad side ; and the 
employment of paper, it must not be disguised, was ac- 
companied with more than one inconvenience : the tex- 
ture of the paper itself was not very smooth, its fibrous 
nature produced traces and unevennesses which prevented 
it from being impressed to an equal extent all over its 
.surface. The paper was, moreover, too porous, it 
expanded and did not always uniformly absorb the 
liquids in which it was plunged ; the photographic proof 

G 



82 THE HISTORY OF PHOTOGRAPHY. 

obtained was no longer characterised by the same abso- 
lute sharpness of line, by the same harmonious degrada- 
tion of light and shade. To alter this it was necessary 
to improve the photographic paper, to purify its pulp, to 
get rid of the grain and irregularities of its surface, and 
to make it homogeneous, smooth, and as clean as that of 
the Daguerreotype plate. 

This problem was carefully studied and cleverly 
solved by an experimentalist, who has played a con- 
siderable part in the history of photography, Niepce de 
Saint-Victor, nephew of the inventor of the heliograph. 
He conceived the happy idea of having recourse to glass,^ 
the surface of which is as smooth and level as that of 
metal, and of covering it with a slight coating of a vis- 
cous liquid, which possessed the property of solidifying 
and in which the impressionable substances could be 
dissolved. 

To obtain his negative, Niepce de Saint-Victor coated 
a sheet of glass thinly with albumen (white of egg), which 
formed a homogeneous, smooth surface, extremely well 
adapted under good conditions to be used in the fixing of 
the image. To sensitise this coat of albumen, the in- 

' Sir John Herschel used glass plates in photography as a support for 
sensitive films in 1839. It is a curious coincidence that Niepce de Saint- 
Victor, some years later, discovered, independently, the use of glass plates 
as supports for his albumen pictures. — Ed. 



PHOTOGRAPHY. 8^ 



ventor impregnated it with iodide of silver, in the follow- 
ing manner : he first plunged it into a bath of iodide of 
potassium, and then into a solution of nitrate of silver ; 
when dry the sensitised glass was ready to use for ob- 
taining a negative picture at the focus of the camera. 
The negative, when fixed, gave paper positives, by means 
of the processes we have already described. 

This discovery of Saint- Victor's was of immense 
importance to photography. But it was not the only 
help the photographic art was to receive from him, his 
various improvements indeed were of such real impor- 
tance that we think it our duty to give a few details 
respecting the clever nephew of Nicephore Niepce: 

Like the discoverer of heliography, he was destined 
for the military career ; leaving the military school at 
Saumur in 1827, he was made a lieutenant of the 1st 
Dragoons in 1842. It was at this time that he began to 
devote himself especially to the study of physics, which 
had always attracted his eminently scientific mind. 

During his stay at Paris, Abel Niepce de Saint- 
Victor's taste for scientific studies received a fresh im- 
pulse. His relative's discovery had given an imperish- 
able glory to the name, and, by a sort of family feeling, 
he seemed to be drawn into the pursuit of science. He 
commenced by studying physics and chemistry, and 



84 THE HISTORY OF PHOTOGRAPHY. 

turned his attention particularly to the investigation of 
the Daguerreotype phenomena. But a provincial town 
offered slender resources to a person in Niepce's position. 
Convinced that the capital would afford him greater faci- 
lities to carry on his researches, he applied to enter the 
Municipal Guard of Paris. 

He was admitted with the grade of lieutenant in 
1845. At the quarters of the Paris Municipal Guard in 
the Saint-Martin suburb, was a room belonging to the 
under officer of police, which was always empty. It was 
in this strangest of laboratories he installed himself 
The camp bed formed his work table, and the shelves 
round the room held the apparatus, the reagents, and all 
the material necessary for his work. It was a curious 
spectacle,, this laboratory in the midst of the barracks, 
this officer perseveringly prosecuting his scientific studies 
in spite of the continual calls of his profession. Our 
men of science are, usually, more at their ease ; they can 
pursue their studies under the most favourable conditions, 
everything which money can obtain to aid them is at 
their disposal ; they have vast well-stored laboratories 
calculated to facilitate their work ; after having had 
masters to teach them, they have pupils to whom they 
impart their learning. When success crowns their efforts 
they have the public, which applauds their discoveries, the 



PHOTOGRAPHY. 85 



Academy which rewards them, and finally Fame which 
smiles upon them. Niepce de Saint-Victor was alone, 
as he was without a master so he was also without 
pupils ; his budget consisted of his lieutenant's pay only, 
a police room served him for laboratory. During the 
day surrounded with all the paraphernalia of the savant, 
he gave himself up to his scientific studies, which were 
constantly being interrupted by the calls of his office ; 
at night, with helmet on head and sword at side, he 
watched in silence over the tranquillity of the city streets, 
endeavouring to chase from his mind the thought of the 
work which was dearest to his heart. 

The laboratory of this clever officer was burnt down 
on February 24, 1848, but afterwards M. Niepce de 
Saint-Victor was enabled to continue his interesting 
studies under excellent conditions, and other facts of the 
highest interest in photography were yet to be discovered 
by the relative of the illustrious Nicephore Niepce. 

In 1847, M. Chevreul laid before the Academy the 
new process of Niepce de Saint- Victor. But a few years 
later, in 1850, albumen was to be replaced by a new 
substance, which offered such advantages that it was not 
long in coming into general use to the exclusion of all 
others : we refer to collodion. 

Gun-cotton was discovered in 1846 by Schoenbein, 



86 THE HISTORY OF PHOTOGRAPHY. 

who published it to the world of science principally as a 
fulminating substance. The new explosive caused uni- 
versal astonishment. This cotton, apparently different 
in no way from ordinary cotton, which exploded like 
gunpowder on contact with fire, caused a veritable stupe- 
faction ; it is obtained by submitting cellular substances 
such as cotton and paper to the action of a mixture of 
nitric and sulphuric acid. M. Schoenbein's method was 
to submit carded cotton to the action of a mixture 
of these acids. As often happens on the invention of 
new products, gun-cotton, which was to change the whole 
art of war, did not in reality bring it many new re- 
sources, but it was to prove of immense importance 
to photography. 

The introduction of collodion in photography is due 
to M. Legray ; ^ a pamphlet published by this clever pho- 
tographer near the end of 1856, makes mention of this 
substance, which Messrs. Bingham and Cundell, some 
months later, also attempted to substitute for albumen. 
Shortly after these experiments were made known, Scott 
Archer, in England, made collodion the basis of a nega- 

' It is well known that M, Legray proposed the use of collodioh in 
1850, while Mr. Archer was prosecuting his independent researches in 
England, but it is to the latter we are indebted for the first practical details 
of a collodion process piiblished in i8'5i, — Ed. 

[See also Mr, Archer's letters to the Athencrnin^ in January 1852, and 
his Manual of the Collodion Photographic Process, published March 1852.] 



PHOTOGRAPHY. S"; 



tive process remarkable for its clearness and finish. It 
is this process, improved and perfected from time to time, 
which for more than twenty years has been the basis of 
nearly every photographic operation. Its principle is 
simple, thus : gun-cotton is dissolved in a mixture of 
alcohol and ether, and the collodion obtained, with the 
addition of iodides, and sometimes of soluble bromides, 
is poured on a glass plate. As soon as it has set 
through evaporation, it is plunged in a bath of nitrate of 
silver in order to impregnate it with iodide and bromide 
of silver. Charged with these insoluble compositions, 
and covered still with free nitrate of silver, the plate is 
exposed for a few seconds to the action of light in the 
camera. It is then removed to a dark room and sub- 
mitted to the action of reducing agents to complete the 
decomposition which the light has commenced, and 
transform the latent image into a visible and negative 
picture. Sulphate of iron and pyrogallic acid are chiefly 
employed to produce this effect. 

After development the picture or image is Jixed, 
that is to say, deprived of the unaffected and still sensi- 
tive salts by means of hyposulphite of soda or cyanide 
of potassium. From a negative thus obtained any 
number of positive pictures on paper may be taken by 



88 THE HISTORY OF PHOTOGRAPHY. 

exposing paper sensitised with silver — placed under and 
in contact with the negative — to the action of light. 

On the appearance of collodion the art of photo- 
graphy may be said to have been completed. We there- 
fore close its history at that epoch. 



PART II. 

THE OPERATIONS AND PROCESSES OF 
PHOTOGRAPHY. 



CHAPTER I. 

THE STUDIO AND APPARATUS. 

ARRANGEMENT OF A GOOD STUDIO— THE DARK ROOM — TERRACE- 
SITTING ROOM — THE INFLUENCE OF LIGHT — ARRANGEMENTS FOR 
LIGHTING THE OBJECT TO BE PHOTOGRAPHED— THE APPARATUS — 
LENSES AND CAMERAS. 

The photographic studio should consist of a room in 
which the camera and photographic accessories may be 
freely used, and of a dark room. It is necessary that 

[In the Appendix the reader will find some formulae in general use for 
obtaining negatives and printing positives on paper by the ordinary ' Wet 
Plate Process' as it is called, in contradistinction to the 'Dry Plate Pro- 
cess,' which is referred to farther on. By the Dry Process excellent results 
are to be obtained, but for general work the Wet Process is greatly to be 
preferred. But whichever process is employed, to get good results, it is a 
sine qua non that the chemicals used are of the best quality. The beginner 
will find it most economical to prepare all the mixtures himself, with the 
exception of the collodion. Before purchasing the more expensive pho- 
tographic tnateriel, such as cameras or lenses, he would do well to get the 
advice of some friend acquainted with the subject.] 



90 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

the latter should not be absolutely dark, as various 
manipulations have to be conducted in it ; it may be 
lightened by means of a window with yellow glass or a 
yellow blind, or even by a lamp with a yellow shade (the 
yellow decomposes the light, allowing only the non- 
actinic or non-sensitive rays to pass through). 

That part of the studio set apart for work not re- 
quiring protection from daylight needs no special de- 
scription. It should have shelves arranged around its 
walls for holding bottles of chemicals, &c. ; a work-table 
for cleaning glasses on, and a pair of scales are the prin- 
cipal necessaries. 

The dark room should be arranged with the greatest 
care ; in it the sensitive plates are prepared, and the 
various delicate processes which have to be guarded from 
daylight are performed. We have said that every ray 
of white light must be carefully excluded. It should be 
conveniently arranged, so that the operator has ready 
at hand all the things he requires when manipulating, 
which he has to do as quickly as possible. {Fig..io.) A 
narrow table is fixed to the wall for supporting the sen- 
sitising baths, which have to be placed in a somewhat 
inclined position. There should be a row of shelves for 
holding the bottles of collodion and other chemicals. It 
is well to have a sink near the table with a tap above it 




Fig. io 
the dark room. 



[Page 90 



THE STUDIO AND APPARATUS. QI 

for washing the proofs ; this tap may be advantageously 
fitted with a piece of indiarubber tubing having a rose 
at the end so that the water may be quickly and easily 
applied over a large surface. 

A terrace well exposed to daylight is also necessary 
for exposing the printing frames containing the nega- 
tives to be reproduced on paper. If possible, there 
should be a second dark room placed near this terrace 
for the preparation of the photographic paper for taking 
positives. 

The room in which the sitter is placed is the most 
important part of a good photographic establishment : 
it should be constructed in a position very accessible to 
the light, and lighted in a special manner. The mode 
of distributing the light in the posing room contributes 
to give the pictures produced that harmony which cha- 
racterises really artistic photographs. 

If the sitting room is only lightened by horizontal win- 
dows placed on one side, or if it receives light from all 
sides at once, the effect of the too strong or too feeble 
light thus obtained is equally prejudicial to obtaining 
good pictures. 

The first condition in a good posing room is that it 
should face the north ; if it is placed at the top of a 
house it should be glazed on one side and on the roof like 



92 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

a conservatory — glass of a clear blue,^ coloured with co- 
balt, should be chosen in preference to all other sorts ; it 
has the property of sifting the light, allowing the chemical 
rays to pass, and producing a soft and harmonious effect. 
The side window and glass roof should be provided with 
large blue blinds capable of being easily drawn across 
any part where it may be necessary to intercept the light. 
To these preliminary precautions should be added others, 
which are particularly recommended by Mr. Liebert, an 
expert photographer. 

' Cleanness of the glass,' says this clever experi- 
mentalist,^ ^ is likewise of great importance in regard to 
the rapidity of operations. The windows should be 
cleaned as often as necessary, so that the light may pro- 
duce its maximum of rapidity. In order to soften and 
modify the effect of the intense glare on the eyes, the 
interior walls should be painted blue or light grey ; 
green, yellow or red colours should be excluded from the 
room as giving unfavourable reflections.' 

We subjoin some further hints from M. Liebert, 
which will be found useful in the employment of light 

' Blue glass used to be greatly in vogue, but the pure homogeneous blue 
which admits only the most actenic rays of the solar spectrum is so difficult to 
obtain that its use has been for the most part abandoned in England. A 
skilful photographer, with the aid of a well-devised set of blinds and white 
glass, may manipulate the light so as to produce any effect he may desire. — Ed. 

2 La Photographie en Amerique. Paris, 1864. 



THE STUDIO AND APPARATUS. 93 

for photography. * The chemical action of light varies 
considerably, according to the state of the atmosphere ; 
on a bright, clear day it is more rapid than in dull, 
gloomy weather. The light, in order to act on the 
chemical substances employed to form the photographic 
picture, should be white. Gas-light, candle-light, even 
the light of the sun passed through a yellow glass, has 
hardly any effect on the nitrate of silver The electric 
light, magnesium light, and daylight darken it. 

* All colours are not reproduced with equal rapidity ; 
thus black, red, yellow, and green take much longer to 
impress themselves than white, blue, lilac, and rose. The 
colours of the object to be photographed must therefore 
be taken into account in regulating the duration of 
exposure.' 

For out-of-door views the most favourable conditions 
are those which place the different points of the land- 
scape to be reproduced in a light of a nearly even in- 
tensity throughout, when the sun, approaching the zenith, 
projects the light from above, because the shadows are 
then least considerable. The light of sunrise and sunset, 
which produces such beautiful effects in Nature, is not 
so well adapted for photography, by reason of the feeble 
photogenic colours which are reflected in red or yellow, 
over the whole landscape. Nevertheless, certain pictorial 



94 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

effects may be obtained by a photographer who is master 
of his art, when, soon after sunrise, or just before sunset, 
long transparent shadows veil the landscape. The time 
should therefore be chosen by the amateur when the sun, 
being at its highest lustre, is in the greatest possible 
harmony with the sky, in order that the objects in the 




PHOTOGRAPHIC BELLOWS CAMERA. 



view should produce an almost equal impression in the 
camera ; the effect of solarisation is thus avoided. 

The apparatus with which photographs are taken, 
and which takes the place of the dark room, is called the 
camera ; ^ it consists of a plain or bellows box, at the 
back of which is a movable frame of ground glass. 



• In the Appendix will be found an illustrated description of a 'rotating 
camera,' for taking panoramic views, &c. 



THE STUDIO AND APPARATUS. 95 

The front is furnished with a brass tube (fig. ii)% con- 
taining the lens. 

The lens is the soul of photography. It should be 
constructed in the best manner possible by means of 
glasses thoroughly achromatised. 

' Everybody knows that the lens as it is used in the 
ordinary camera is a convergent glass, giving a reduced 
and an inverted image of exterior objects. This image 
is projected on to the ground focussing glass, which is 
placed at the back of the camera. It is hardly necessary 
to say that the size of the picture thus formed de- 
pends on the size of the lens and the distance from the 
object. 

There are two sorts of lenses used in photography : 
the simple lens and the compound lens. The first is prin- 
cipally used for landscapes : it is constructed in such a 
manner as to give to all parts of the picture the same 
character of fineness, sharpness, and exactitude. The 
second is chiefly employed for the execution of portraits ; 
the greater convexity of its glasses throws a very 
luminous image on the centre of the plate, though 
becoming less so as its edges are approached, thus 
enabling the operator to obtain a picture almost instan- 
taneously. 

The single lens consists of two glasses, the one con- 



96 OPERATIONS AND PROCESSES OF PPIOTOGRAPHY. 

cave, which fits into the convexity of the other. This 
system of two glasses thus forms a single achromatic 
lens, the object of which is to destroy the coloured fringe 
which appears round the edges of non-achromatised 
glasses, and to render the foci of the different coloured 
rays of light coincident. The double or compound lens 
consists of the single achromatic lens with the addition 
of two other glasses, the first convergent, and the second 



Fig. 12. 




THE LENS, WITH ITS RACKWORK AND CAP. 

concavo-convex. With the compound lens on a bright 
day, it is possible to obtain a photograph in one or two 
seconds; it is therefore employed, as we have already 
said, for taking portraits. Lenses are also made which 
can be used either for portrait or landscape work ; in 
every case the lens-tube is furnished with a diaphragm,^ 

' In Fig. 1 7 the diaphragm is the piece of metal with circular opening 
in the centre in the slit of the lens tube ; when pushed down into its place 
between the glasses the amount of light admitted into the camera is regu- 
lated by the size of its aperture. 



THE STUDIO AND APPARATUS. 



97 



the object of which is to confer sharpness on the 
image which would otherwise be indistinct ; it is mova- 
ble and can be used of various sizes, according to cir- 
cumstances. The camera is also provided with a small 

Fig. 13. 




SIMPLE PHOTOGRAPHIC APPARATUS. 



pinion which works in a line of teeth on the inner 
movable brass tube containing the lenses, by means 
of which the focus may be adjusted wi^h the greatest 
nicety. 

Fig. 12 represents the brass tube containing the 
lens ; the milled head and rackwork are seen on the top 

H 



98 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 



of the tube ; and the remaining piece is the cap for ex- 
cluding light. 

The lens tube fixes on to the camera by means of a 
screw which works in a metal worm fixed to the camera. 
The body of the camera is formed of two distinct parts, 
sliding one into another in such a way that the operator 
can at will vary the distance which separates the lens 
from the focussing glass. This mobility of the focussing 
glass has been realised in a very simple practical manner, 
on the bellows principle, combined with a hinge, by 
means of which the focussing glass and the dark slide 
can be placed in all the positions necessary in the various 
conditions of taking a photographic picture. 

Fig. 1 1 represents a bellows camera with hinge which 
is light and very portable, and can be shut up into a 
very small space. 

In the majority of cases, very good results can be 
obtained with a camera formed as shown in fig. 13, with- 
out bellows. The two parts of 
this camera are made of wood, 
and represented by M and N. 
A and B are the tubes contain- 
ing the lenses movable by 
means of the pinion V which 
'^' ^^' turns the rackwork. The cap 

is shown a little above the lens tube. The frame con- 




THE STUDIO AND APPARATUS. 



99 



taining the focussing ground glass marked G works in a 
groove, into which also fits the dark slide (see fig. 14), con- 
taining the plate to be exposed. When the focus has 



Fig. 15- 




THE CAMERA STAND. 



been obtained on the ground glass the latter is drawn out, 
and the dark slide containing the sensitised plate slipped 
into its place, so that when it is exposed to the light 



lOO OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

exactly the same picture is thrown upon it as on the 
ground glass. A section of the lens arrangement used in 
this camera is shown in fig. 14. A is the fixed tube ; B the 
sliding tube which is enclosed by the former, and which 
allows the two systems of glasses at E and D to be moved. 
The object of the lens, as we have explained, is to 



'ig. 16. 




THE DARK SLIDE. 



project a picture of exterior objects on to a screen 
placed at the back of the camera. This screen consists 
of a sheet of ground glass ; to examine the picture, which 
is reversed, the operator has to exclude as much light as 
possible from it, and for this purpose places a dark cloth 
over his head and shoulders ; but this is a manoeuvre too 
well known to need description. 



THE STUDIO AND APPARATUS, lOI 

Fig. 1 5 represents a camera stand, by means of which 
the camera can be raised or lowered or fixed at any in- 
clination desired. This is done by the aid of a comph- 
cated arrangement of screws as shown in our illustra- 
tion. 

To expose the sensitised plate in the camera, it is 




TWIN-LENS CAMERA, SHOWING DARK SLIDE AND DIAPHRAGMS. 

fixed in a frame called the dark slide, which, as before 
mentioned, fits into the camera in the same plane as the 
focussing glass. 

The dark slide is shown in fig. i6 ; it is made up of 
a frame forming a box. At the back of the frame is a 
door which opens and shuts. The sensitised plate on 
being removed from the bath in the dark room is placed 



102 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

in the dark slide, film side inwards, and the door being 
shut, a spring, as shown in the illustration, presses 
against the uncoated surface of the glass, and holds it 
firmly in its place. On the front of the dark slide 
is another door, also made of wood, which slides in a 
groove, and when it is lifted up in the camera, until it 
can be turned over on hinges as shown in the drawing, 
the light of course falls on the sensitised surface of the 
plate as soon as the lens cap is removed. On the other 
hand, when it and the other door are both shut they 
keep the plate in perfect darkness, and thus permit the 
operator to carry it from the dark room to the camera 
and vice versa. 

Figure 17 represents the different positions of the 
dark slide before commencing operations. It shows at 
the same time the general appearance of a good twin lens 
camera. The photographer has examined on the 
ground glass the picture to be reproduced ; he has 
obtained the necessary distinctness or sharpness by 
moving the brass tube containing the lens by means of 
the pinion ; he has, in fact, focussed the picture, that is to 
say 'found, by trial, the optical focus point, the only point 
at which the picture presents perfect sharpness. He can 
now place the sensitised plate at this focus. He carries 
it in its dark slide, and after removing the ground glass. 



THE STUDIO AND APPARATUS. 



103 



carefully slides it into its place. 
He now pulls out the movable 
door, and the plate is then only 
protected from the light by the 
brass cap on the lens tube. He 
gives a last caution to the 
sitter to 'keep quite still,' re- 
moves the cap, and instantly 
the picture of the sitter im- 
prints itself on the sensitive 
film. The cap is replaced, the 
sliding door again pushed 
down, and the plate in its 
slide removed to the dark room 
to be developed, intensified if 
necessary, and lastly fixed, as 
will be explained farther on. 

We shall have occasion to 
describe a great variety of 
other apparatus employed in 
photography in the course of 
our account of the different 
processes and methods which 
require their use. We shall, 
however, close this chapter "^^ 
with a short description of 



Fig. 18. 




THE HEAD-REST. 



104 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

the head-rest represented in fig. i8, an instrument 
which no portrait studio should be without. There 
are very few persons who can keep perfectly still, even 
for a few seconds. Their heads move without their 
being aware of it. They should, therefore, after taking 
graceful pose be supported by resting the head in the 
half-circle of the head-rest. 

In adjusting the latter care should be taken that the 
position of the sitter is not altered, otherwise it will very 
often happen that a most objectionable stiffness is im- 
parted to the patient, and a caricature rather than a por- 
trait is the result. 



I05 



CHAPTER II. 

THE NEGATIVE. 

MANIPULATION OF THE PHOTOGRAPH — CLEANING THE PLATE— COATING 
THE PLATE WITH COLLODION— PLACING IT IN THE SILVER BATH — 
EXPOSURE IN THE CAMERA — DEVELOPMENT,FIXING, AND VARNISHING. 

Having thus got ready our studio, and the most neces- 
sary apparatus, we shall proceed to describe the delicate 
manipulations required to obtain a good photograph. 

Cleaning the Plate. — After carefully selecting a 
number of glass plates of the required size, free from 
scratches, air-bubbles, or stains, and perfectly flat, the 
next process is to clean them. This operation does not 
consist, as might be supposed, in simply rubbing them 
with a cloth, but is much more minute ^nd delicate. The 
plate is placed in a plate-holder (fig. 19), a wooden 
frame provided with a screw vice by means of which the 
glass can be held firmly without its being necessary to 
touch it with the fingers. The slightest contact with the 
hand, always a little greasy, is sufficient to prevent the 
perfect adhesion of the collodion. A plate-cleaning paste 



I06 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

is now made by mixing Tripoli powder and alcohol in a 
bottle. After shaking the bottle well, a little of the 
mixture is poured on to a piece of flannel, and the plate 
well rubbed with it. It is next dried with filtering paper, 
or, better still, with a paper of great delicacy called 
Japanese paper. In winter it is well to heat the plates 
slightly, to get rid of the humidity caused by the pre- 



Fig. 19. 




ni 



PLATE-HOLDER. 



cipitation of moisture from the warmer atmosphere. We 
cannot insist too strongly on the extreme importance of 
perfectly clean plates ; if sufficient care is not taken in 
this respect, the success of the operation is at once com- 
promised. 

Collodion, its preparation. — Collodion is a thick trans- 
parent liquid, which possesses the property of solidifying 
when exposed to the air. It is made by dissolving gun- 
cotton in a mixture of alcohol and ether. Although it 



THE NEGATIVE. 10/ 

is easy to procure good collodion ready made, we think 
it may be useful if we give the method of making it.^ 

Coating the plate with Collodion. — The collodion being 
thus obtained and ready to our hand in the dark room, 
we will proceed to describe the process of taking a pho- 
tographic negative. 

• Mix one part of dry pulverised nitrate of potash with three parts of 
concentrated sulphuric acid in a porcelain capsule, the nitrate of potash being 
put in first, and the sulphuric acid slowly added little by little. The 
mixture must be constantly stirred with a glass rod. It is then gently warmed 
to a heat of 60° centesiviaux, ascertained by the mercurial thennometer. 
This may be done by adding water to the mixture, the quantity depending 
on the specific gravity of the acid. The cotton, which should be of good 
quality, well carded, very fine and clean, is now immersed in the mixture 
and well stiiTed and moved about with a glass spoon, so as to soak it well 
all through. It is left in contact with the sulphuric acid for the space of 
two hours, and is then well washed. It only remains to diy it and the 
gun-cotton is made. 

To test the quality of the gun-cotton a little of it is ignited ; it should 
burn very rapidly, without leaving any black residue. 

The gun-cotton thus prepared is now dissolved in a mixture of alcohol 
and ether in the following proportions for plain negative collodion : — 

Alcohol, sp. gr. 725 2\ fluid ounces. 

Sulphuric Ether, sp. gr. -805 . . . 5 ,, ,, 

Sixty grains of gun-cotton can be dissolved in the above quantity of 
alcohol and ether. The alcohol is first poured into a large-necked glass 
bottle with ground-glass stopper. The gun-cotton is next introduced, and 
the bottle well shaken in order to thoroughly soak it. Lastly the sulphuric 
ether is added, and the whole well shaken again until all the cotton is 
dissolved. A viscous syrupy liquid is thus obtained ; it should be allowed 
to stand for forty-eight hours, and then decanted into a clean dry bottle, in 
which it can be kept until required to be sensitised. 

To sensitise the collodion it is necessary to add certain chemical agents 
which, combined with the nitrate of silver, form a solution sensitive to light. 



I08 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

The plate, which has been cleaned with the greatest 
care, has now to be covered with a slight coating of sen- 
sitised collodion. This operation of pouring on the 
collodion is a somewhat delicate one, and requires a little 
skill and practice. The plate is held by one of the 
corners in a horizontal position between the thumb and 
forefinger ; taking the collodion bottle in the other hand 
a small quantity, sufficient when spread out to cover the 
plate (fig. 20), is poured gently on to the middle. By 



Various substances are employed for this purpose, but the iodides and 
bromides are chiefly used. The following alcoholic solution is recommended 
by Mr. A. Liebert for sensitising collodion : — 

ns. (Eng.) 



Iodide of Potassium . 


330 grai 


Bromide of Potassium 


120 , 


Iodide of Ammonium . 


270 , 


Bromide of Ammonium 


150 , 


Iodide of Cadmium . . 


300 , 


Bromide of Cadmium 


150 , 


Iodide of Zinc 


180 , 


Alcohol of 40** . . . . 


if Imp. Pint = 35 oz. 



The recipes for making sensitised collodion vary to an almost infinite 
extent, and we cannot pretend to give a list of formulas, which woidd take 
us too far out of our way, and give the book too much the form of a 
treatise. We repeat that amateurs, and even photographers themselves, 
are in the habit of procuring their collodion ready sensitised of good 
makers. The methods we give are chiefly to enable the reader to under- 
stand the simple operations of photography. 

[I need hardly add that it would be unwise for the amateur who has 
not made himself thoroughly acquainted with the chemistry of the operation 
to attempt to make his own collodion, as he would encounter a number of 
technical difficulties which can only be overcome by those who have made 
the manufacture of collodion their special study.— Ei).] 



THE NEGATIVE. 



09 



inclining the plate the liquid is made to flow first to the 
corner where the glass is held, avoiding contact with the 

Fig. 20. 




COATING THE PLATE. FIRST POSITION OF THE HANDS. 



Fig. 21 




SecOKD POSITION OF THE HAND.'?, 



thumb, then to the top left-hand corner, then to the right 



no OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

one, and lastly the surplus is poured back into the collo- 
dion bottle from the remaining corner (fig. 21).' Care 
must be taken that the collodion does not flow twice over 
the same spot, or, instead of being level, the surface will 
present unevennesses which will prove injurious to the 
development of the image. In order not to waste un- 
necessarily so expensive a substance as collodion, the 
beginner should get his hand in a little by practising 
with gum-water of a similar consistency. When the 
plate is coated and found to be free from streaks, 
points or blurs of any sort, and clear and trans- 
parent, it is allowed a few seconds to set by evaporation, 
it is then ready for immersion in the silver bath. 

The sensitising silver bath for negatives may be 
made as follows : — 

Recrystallised neutral Nitrate of Silver . . 350 grains. 

Distilled Water 10 fluid ounces. 

Glacial Acetic Acid i drop. 

Iodide of Potassium i grain. 

Dissolve and filter. 

The bath for positives should be of 40 grains silver to 
the ounce of water. 

Immersion in the sensitising bath. — The operation of 
plunging the plate into the silver bath must be performed 

^ Whilst the surplus liquid is running off into the bottle, and until it 
sets, which will be almost directly, the plate must be moved backrt'ards 
and forwards, or ridges will form on the film. 



THE NEGATIVE. 



Ill 



rapidly without stopping, in order that the collodion film 
may be brought into contact with the liquid over its 

Fig. 22. 




SENSITISING TRAY. 



whole surface at the same moment. The 
dish containing the bath is tilted a little, 
so that the liquid collects at one end ; the 
edge of the plate is then placed (see fig. 22) 
against the other end, and by means of a 
silver hook lowered into the liquid, the 
dish being brought back to the horizontal 
position at the same time ; by this means 
the silver is made to flow evenly over the 
whole surface. The plate is allowed to 



Fig. 23. 



SILVER HOOK FOR 
RAISI.NG AND LOW- 
ERING THE PLATE. 



112 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

remain for a few seconds in the bath and then examined 
by raising one end with the hook ; it should present a 
smooth, clear surface of an opaline tint ; should this not 
be the case, and the plate have a greasy appearance, 

Fig. 24. 



GLASS BATH IN CASE WITH GLASS DIPPER. 



it must be allowed to remain a little longer in the 
bath. Gently raising the plate in and out of the 
liquid accelerates the action of the silver. 

Fig. 24 represents another and very convenient form 
of bath, usually made of glass ; its interior sides are 



THE NEGATIVE. II3 



concave, so that when the plate is slid in by means of a 
glass or other dipper, only its edges come in contact with 
the sides of the bath, the film being thus protected from 
scratches. Though this form of bath requires a larger 
quantity of the silver solution, it has nevertheless the 
advantage of being much more slowly exhausted, and 
can be protected from dust even when in use by means 
of a cap fitting on to the top. 

The plate thus prepared is placed in the dark slide 
and kept in a perpendicular position, and is now ready for 
exposure in the camera. 

Exposure in the camera. — It is impossible to give 
any definite rule as to the time the plate should be ex- 
posed in the camera ; the power of the lens, amount of 
light, quality of the collodion, colours of the object to be 
reproduced, &c., have all to be taken into consideration. 
Practice can alone guide the photographer. 

In the studio the time of exposure varies from three 
to thirty seconds. For landscapes the plate should be 
exposed in accordance with the nature of the collodion, 
the developer used, &c. 

The amateur should accustom himself to count the 
seconds mentally, instead of always having to rely on a 
watch. As soon as the plate has been sufficiently ex- 
posed to the light, the sliding door is shut down and the 

I 



114 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

plate removed in its frame to the dark room, where the 
picture has next to be developed. 

Development of the image. — After carefully exclud- 
ing all white light from the room the plate is now re- 
moved from the dark slide and held by a corner between 
the thumb and forefinger in a horizontal position ; the 
developing solution is then rapidly poured over its sur- 
face in such a way that the entire film is covered at 
once, as if it is arrested and allowed to remain for a second 

Fig. 25. 




WASHING THE DEVELOPED IMAGE. 



longer in one place than another, it will certainly produce 
an indelible stain.* After the liquid has been made to 



The developer for collodion negatives is formed of a solution of proto- 



THE NEGATIVE. II5 



flow in all directions it is returned to the glass and the 
operation repeated until the image is sufficiently de- 
veloped. Before the application of the developer the 
plate presents an exactly similar appearance to what it 
did prior to exposure, and not the slightest trace of 
any picture is visible, but almost the instant the develop- 
ing agent is applied a change takes place ; first the 
lights appear, then the shadows, then the half-tones. 
But it is a negative, that is to say the whites of the 
model appear in black on the glass and vice versa. 

It is during this operation that one may easily de- 
termine if the time of exposure has been correctly calcu- 
lated. If it has been too short, the whites appear in- 
stantly almost like ink blots, whilst in the shades and 
blacks the collodion remains opaline and unaltered. If, 
on the other hand, the exposure has been too long, the 
whole surface becomes covered with a greyish cloudiness 
on contact with the developer, and the picture is without 

sulphate of iron in distilled water. A little acetic acid is usually added 
with a few dops of alcohol. The following makes a good developer : — 

Distilled Water ...... i ounce. 

Protosulphate of Iron . . . . • '5 grains. 

Acetic Acid 20 minims. 

Alcohol ....... 25 minims. 

This solution can be made just before it is wanted for use. The 
strength and proportions of the ingredients in this solution may be greatly 
modified, but the alcohol should be added little by little until the developer 
flows freely and evenly over the plate. 

I 2 



Il6 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

sharpness. In either case it is necessary to recommence 
the operation. 

When the exposure has been nicely timed, the pic- 
ture appears gradually as if by enchantment, clear, pure, 
sharp ; the details are admirably distinct ; the lights are 
free from stains, and the blacks are represented by 
distinct tones varying according to the depths of the 
shadows. 

A great number of substances are known at the 
present time which are capable of developing the picture; 
bisulphate of iron and ammonia, pyrogallic and formic 
acid, have been recommended by some operators. 

It often happens that a negative picture is perfect as 
regards sharpness, but is wanting in intensity. In this 
case the vigour necessary to obtain a positive proof may 
be imparted to it by the process of intensifying. 

Intensifying, — The developed plate is well washed, 
and is then subjected to the action of the developing 
solution, which must, however, contain a small quantity 
of the silver solution (one or two drops of the bath will 
do very well).' An intensifying solution may also be 
formed of water to which pyrogallic acid dissolved in 
alcohol and acetic acid has been added. 

• Re-developing solution : — 

Pyrogallic Acid . . . . .2 grains. 

Citric Acid ...... 3 grains. 

Water i ounce. 



THE NEGATIVE. 11/ 



After the operation of intensifying, as also after that 
of development, the plate must be well washed, to re- 
move all traces of the iron and reagents which have been 
used. At least a quart of water should be poured on 
to the plate, care being taken that it does not get under 
the collodion film. 

Fixing the negative. — To fix the negative it is neces- 
sary to deprive it of the iodide of silver, which, not 
having been affected by the light, would darken when 
exposed to it. 

Hyposulphite of soda dissolves the unaltered iodide 
of silver. 

The negative being developed and washed is now 
plunged into a solution of hyposulphite of soda in water 
contained in a porcelain dish (8 oz. of hypo, to 40 oz. of 
water), and allowed to remain there for a minute or two 
until the yellow coating of iodide of silver is entirely 
dissolved. The plate should be raised out of the bath with 
a hook and carefully examined and returned to the 
bath if the slightest trace of the silver is visible. When 
perfectly clear it must be well washed as before to get 
rid of the hyposulphite adhering to its surface. 

Cyanide of potassium (a most deadly poison) is also 
used for fixing purposes ; it is employed in the same way 
as the developing solution, and is cleaner and gives per- 



Il8 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

haps a more vigorous, sharp picture, with finer detail 
than the hypo. (8 or lo grains of cyanide of potassium 
to I oz. of water). 

The negative is now finished and may be exposed to 
light. But the collodion film is liable to be scratched on 
the least contact with a hard surface or with the finger 
nails ; it is therefore necessary to protect it by covering 
it R\'ith a coat of varnish. 

A special varnish is sold for this purpose, which is 



Fig. 26. 




RACK FOR DRYING PLATES. 



transparent, soon dries, and becomes very hard. The 
plate should be gently heated over a spirit lamp or 



THE NEGATIVE. 



119 



before a fire (the safer plan), until it can be just borne on 
the back of the hand, the varnish is then poured on 
exactly as if coating a plate with collodion, and the 
excess returned to the bottle ; the plate is then again 
gently heated until quite dry, when the picture will be 
protected from the effect of any accidental abrasion. 

A less perfect temporary protection is afforded by a 
solution of gum arable (10 parts of gum to about 100 of 
water). 

Fig. 2^ represents a useful form of box for containing 



Fig. 27. 




PLATE BOX. 

glass negatives, which are held in grooves, and kept free 
from contact with each other. 



120 OPERATIONS ANP PROCESSES OF PHOTOGRAPHY 

The image of the camera which has thus been de- 
veloped, fixed, and varnished, adheres to the glass, but 
it presents a negative picture of which, viewed by trans- 
mitted light, the blacks are the whites of the model. 

We shall now see how the positive proof on paper is 
obtained ; but we think it would be well first to point 
out a few characteristics by which a good negative may 
be known. It is not always an easy matter to determine ; 
to an unpractised eye a plate might appear excellent, 
in which a skilful operator would perceive faults which 
would prevent its yielding a good positive. In a good 
negative viewed by transmitted light the shadows, 
draperies, and stuffs should be highly transparent. The 
whites and high lights on the contrary should appear 
almost perfectly black or opaque. 

It should also present a marked shading between the 
half-tones and in general a well-defined gradation of 
light and shade. If during this examination pin-holes, 
stains or streaks are apparent, or if the most minute 
details and smallest objects are not clearly and sharply 
defined, another photograph should be taken. The im- 
perfections of the negative are exaggerated in the print, 
and all one's toil and trouble thrown away. 

It often happens that the operator searches in vain 
for the cause of imperfections in a negative, in taking 



THE NEGATIVE. 121 



which he seems to have used every precaution ; it is im- 
possible to lay down fixed rules to meet every failure. 
But the beginner should bear in mind that unforeseen 
accidents are rocks ahead, which he will frequently meet 
with in his labours. 

The photographer, like the chemist, should be patient, 
persevering, and endowed with tenacity ; difficulties, far 
from discouraging, should serve to stimulate him ; he 
should not be disheartened at repeated failure, but learn 
to lean more and more on that great teacher, experience. 



122 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 



CHAPTER III. 

THE POSITIVE ON PAPER. 

PRINTING ON PAPER— OF THE NATURE AND QUALITIES OF PHOTO- 
GRAPHIC PAPERS — VIGNETTES— EXPOSURE TO THE LIGHT— TONING, 
FIXING, PRESSING THE PROOFS. 

Preparation of the sensitised paper. — Photographic paper 
can be bought partially prepared ; it is formed of close- 
grained pulp and presents a surface smooth and 
glossy. 

It is easily prepared. A paper of good quality is 
chosen, its surface must be free from stains. It is neces- 
sary that the sizing of the paper should be very care- 
fully done. The different processes of sizing give diffe- 
rent colours in the positive. If albumen is used, the 
proof will be slightly red ; whilst if gelatine is used, it 
will be of an orange-red colour.^ 

The paper being chosen, the albumenised being 
most generally used, it is next plunged into a solution 

• The colour, as will be seen, depends greatly on the subsequent toning 
with gold. — Ed. 



THE POSITIVE ON PAPER. 1 23 

of salt or chloride of sodium (450 grs. to 2 pints of 
water), in which it is allowed to remain for a few minutes, 
and is then dried in the air. To sensitise the paper thus 
prepared, it is only necessary to float the sized surface 
on a bath of nitrate of silver (60 grains of silver to i 
ounce of distilled water) contained in a porcelain dish. 
When the surface is well saturated, it is allowed to dry in 
the dark. 

The albumenised paper of commerce contains 
chloride of sodium or ammonium, and to sensitise it it is 
only necessary to float it on the silver bath ; but it ought 
not to be sensitised long before it is intended for use, as 
it soon turns yellow even when kept in the dark. 

It may be well to mention here that the silver bath 
for the collodion plate must be kept separate, and never 
used for any other purpose. The slightest admixture of 
any foreign substance would at once render it useless. 
It should be filtered when necessary. 

The bath for sensitising the paper can be used over 
and over again, nitrate of silver being added from time 
to time to strengthen it. The solution will become dis- 
coloured after a few sheets have been floated on it, but 
this colouring matter can be readily precipitated by 
means of a little Kaolin powder, when the cleared portion 
of the liquid may be gently decanted into another bottle. 



124 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

Printing from the negative. — Special frames called 
printing frames of various sizes are used in this operation. 
The printing frame, oblong in form, is made of wood to 

Fig. 28, 




THE PRINTING FRAME. 



hold the glass plate, in the same way as an ordinary 
picture frame, but the back is provided with a double 
door hinged across the centre, which can be fastened 
down by means of transverse bars of wood (see fig. 28). 
The printing frame is provided with a sheet of plate 
glass, which must be perfectly clean on both sides ; the 
negative is then laid down with its uncoated side next 
the plate glass. The sensitised surface of the paper is 
now placed on the collodion film and the whole securely 
fastened, and held in close contact by means of the 
wooden back, which is lined with black felt. This 
operation having been conducted in the dark room, the 
plate is now ready for exposure to sun-light. 



THE POSITIVE ON PAPER. 125 

If the negative is vigorous and intense, it may be 
exposed to the direct rays of the sun, if weak and not 
sufficiently intense, it should be placed in the shade. 
During the process of printing, it is necessary to examine 
the proof from time to time until the requisite depth of 
colour is attained. This may be done, of course in the 
shade, by removing one of the transverse bars and turn- 
ing back the top half of the hinged back ; the part of 
the paper thus set free can then be seen without fear of 
shifting, which would of course spoil the picture. If not 
sufficiently printed, the paper is again fastened down, 
and the exposure continued (fig. 29 represents the print- 
ing frame exposed to the sun). 

When vignette pictures are required, a vignette 
glass is used.^ This is a glass colourless in the 
centre, but towards the sides tinted yellow, the colour 
gradually increasing in depth. A vignette glass may be 
made by pasting layers of paper over a glass plate in 
such a way that whilst the desired space in the middle 

' The simplest method of vignetting is to cut an oval aperture in a sheet 
of opaque cardboard, about a third smaller than the space to be taken up 
by the finished picture. The aperture must then be covered by a thin sheet 
of tissue paper. This vignetting screen is fixed outside the plate-glass of 
the frame, care being taken to place the aperture directly above the part to 
be vignetted. When the card is in position the frame must then be placed 
so that the direct rays of the sun passing through the tissue paper will 
become diffused, and print a delicately shaded vignette of the required 
dimensions. — Ed. 



126 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

of the glass is left open, it gradually becomes opaque 
towards the edges, the thickest layer of paper being 

Fis:. 29. 




PRINTING FRAMES EXIOSED TO THE LIGHT. 



farthest from the transparent centre. The action of the 
vignette glass will be easily understood. It is placed 

Fig. 30. 




SIMPLE PRINTING FRAME. 



over the negative, and thus the action of the light is 
confined to the transparency of the centre, acting only 



THE POSITIVE ON PAPER. 12/ 

slightly through the thinner paper, or fainter yellow of 
the vignette glass ; the rest of the proof being perfectly 
protected, a white background is thus obtained. 

As soon as the printing has been sufficiently pro- 
longed (the time varies according to the intensity of the 
light), and shows the desired depth of colour, it is re- 
moved from the frame in the dark room, and subjected 
to the operation of toning and fixing. 

An albumenised print on being taken from the frame 
should be of a very dark brown tone, or slightly bronzed 
in the shadows ; it will lose much of its intensity when 
fixed ; the operator therefore always prints his pictures a 
deeper colour than he desires the finished proof. 

Toning. — If the excess of silver is at once removed 
from the print by means of hyposulphite of soda, the 
result is a picture deficient in depth, and of a disagreeable 
pale red colour. The print, after being allowed to soak 
in a basin of cold water, is therefore first plunged in a 
toning solution formed of 5 or 6 grains of chloride of 
gold to 2 pints of water, a few grains of acetate of soda,* 
or about 100 grains or half a tea-spoonful of carbonate of 
soda being added ; the mixture must be allowed to rest 

• Acetate of Soda i drachm. 

Chloride of Gold ..... 3 grains. 
* Water 20 ounces. 



128 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

for about fifteen minutes before it is used. Whilst in this 
solution the prints will gradually become of a vigorous 
violet or black tone according to the time they are 
allowed to remain in it ; which is usually from lo to 15 
minutes, until indeed they present the deep sepia colour 
which constitutes the true beauty of the photograph.^ 

Fixing. — The print being properly toned and sub- 
sequently well washed is then ready for fixing. The 
process of fixing the positive is very similar to that of 
the negative. Hyposulphite of soda neutralised by 
the addition of one per cent, of chalk gives very good 
results (6 oz. of hypo, to 2 pints of water). An im- 
mersion of fifteen minutes in this solution will be 
sufficient to remove the unaltered silver, and after being 
again well soaked in water three or four times changed, 
and dried, the proof is finished. 

To ascertain if the print is sufficiently washed, a few 
drops of the last bath it is soaked in are allowed to drip 
from it into a glass, a small quantity of bichloride of 
mercury (corrosive sublimate) in solution is then added. 

' There are various solutions used for toning, but that we have given 
is perhaps one of the best. If acetate of soda is used the solution must 
stand for ten or twelve hours before any prints are toned in it ; but it will 
keep good for months, a few grains of gold being added from time to time 
to keep up its strength. The carbonate of soda solution can be used almost 
as soon as made, but will not keep long. 



THE rOSITIVE ON PAPER. 



129 



If the print has been sufficiently washed there will be 
no precipitate, if on the contrary there is a precipitate, 
then the washing must be continued until such reaction 
does not manifest itself. 

Motmting and Rolling. — The proof after being thus 



Fig. 31- 




THE ROLLING PRESS. 



thoroughly washed is hung up to dry by one of its 
corners to a cord stretched across the studio, and when dry 
placed in a press or under a heavy weight to prevent its 
creasing. When cut to the right size it only remains to 
mount the proof on cardboard and to roll it. 

K 



I30 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

The mounting is best effected with a starch paste 
prepared with boihng water. The rolling is done by 
means of a special press (see fig. 31) formed of a smooth 
metal plate which can be moved horizontally backwards 
and forwards under a roller by means of a toothed 
wheel and pinion. The mounted proofs after being dried 
in a warm room are placed on the plate (as shown in the 
illustration), and then subjected to great pressure by 
being passed under the roller. This gives them a 
beautiful gloss and finish. 

Such are the different operations which have to be 
performed to obtain a positive photographic proof by 
the most generally practised method from a collodion 
negative. We will only add that, however minute the 
descriptions, practice is the operator's best guide. He 
should endeavour to master the theory of the different 
processes, but must not forget that a long apprenticeship 
is necessary, and that patience and unwearying applica- 
tion are indispensable qualities in the photographer. 

To anyone ever so little acquainted with chemical 
manipulations the different operations which we have 
just described are not very difficult ; but what protracted 
efforts, what a delicate, patient, minute feeling of the way 
it required on the part of the inventors of the wonderful 
art ! What an abyss of labour and research separate 



THE POSITIVE ON PAPER. • 131 

the actual methods of which we have just given an 
outHne, from the first experiments of Niepce and 
Daguerre ! 

After these grand inventors, what numbers of in- 
genious and laborious minds have long worked at the 
problems of photography, each adding some new ele- 
ments to the results obtained before them ! 

May we not say that it is the character of the works 
of modern science to be in a great measure the result of 
multiplied efforts, isolated from each other, but simul- 
taneous and all tending to the same end ? Most of the 
discoveries of our century are a striking proof of this ; 
and photography is certainly one of those which has de- 
manded the greatest concourse of intelligent workers, 
pursuing with perseverance researches always difficult 
and often unprofitable. 



K 2 



132 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 



CHAPTER IV. 

THEORY AND PRACTICE. 

EXPLANATION OF PHOTOGRAPHIC OPERATIONS — NECESSITY OF LONG 
PRACTICE — MODIFICATIONS IN PROCESSES REQUIRED BY DIFFERENT 
SORTS OF PHOTOGRAPHY— PHOTOGRAPHY AND TRAVEL— LANDSCAPES 
— SKIES —PORTRAITS— INSTANTANEOUS PHOTOGRAPHY. 

We have described the different operations which the 
production of a photographic proof necessitates ; we do 
not think it is necessary to expatiate on the theory of 
the reactions on which is based the series of photo- 
graphic manipulations. In the historical part w^e have 
already referred to the scientific groundwork of photo- 
graphy ; a few new details may, however, help to better 
fix the reader's ideas. 

It is not known by what wonderful influence light 
affects certain chemical agents ; science is almost always 
powerless to explain causes; it discovers effects, it brings 
them under control and profits by their application. 

Light acts on the nitrates of silver.* Why ? No 

' Light, as we have seen, acts also on a great number of other substances. 
Here is a curious experiment which plainly shows its action. It was made 
by Messrs. Gamier and Salmon, and published in the Bulletin of the French 



THEORY AND PRACTICE. 1 33 

one knows and perhaps no one ever will know, but the 
fact is manifest, and this action is the fundamental basis 
of photography. 

The glass plate is covered with collodion, a viscous 
substance which solidifies on contact with air, and is 
well adapted as a base for the silver solution. The col- 
lodion contains iodide of potassium ; when the coated 
plate is plunged into the nitrate of silver bath, the iodide 
of potassium is transformed into iodide of silver. 

The plate thus sensitised is exposed in the camera. 
The light acts on the iodide of silver in the light parts of 
the picture, leaving the shadows intact. On being taken 
from the camera the picture is developed by means of a 
solution of proto-sulphate of iron to which acetic acid has 
been added. The sub-chloride of silver formed by the 
action of light being completely reduced, the metallic silver 
is deposited and soon becomes a very pronounced and 
vigorous dark shade. If not sufficiently vigorous at first 
it is intensified by the addition of a little nitrate of 
silver solution to the redeveloper, which is poured 
over the plate, and a fresh quantity of metal deposits on 
the parts already reduced, strengthening the picture and 

Photographic Society. Sulphur undergoes a singular alteration when sub- 
mitted to the action of light. If, after being thus exposed, it is brought 
into contact with fumes of mercury, the fumes only attack those parts which 
have been acted upon by the light, turning them a brown-yellow colour. 



134 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

giving it greater intensity. The fixing is done by means 
of hyposulphite of soda or cyanide of potassium ; these 
salts dissolve the iodide of silver which has not been 
affected by the light. 

It will be seen that these theoretical outlines are ver>^ 
simple ; it is not necessary to be versed in the study of 
chemistry to understand them. But the theory of an art 
and the being able to practise it are very different things. 
The latter is only to be acquired by long and patient 
manipulations, by numerous and often-repeated experi- 
ments. It is the more difficult to be taught in a work 
such as the present, inasmuch as it varies according to 
the result desired. 

All that we have so far said on photographic opera- 
tions refers principally to experiments made in a studio 
where the light can be controlled at will, and where a 
dark room and all the necessary apparatus are at hand. 
But we have not entered into the particular details of the 
precautions which are necessary in taking portraits from 
nature; we have passed in silence the accidental causes 
which alter a negative — in one word the minutiae which 
practice alone can teach. Just as it is impossible to become 
a chemist without studying in a laboratory, so is it folly to 
hope to become a photographer except with the col- 
lodion bottle in the hand and the camera before the eyes. 



THEORY AND PRACTICE. 1 35 

Nevertheless, as the inexperienced beginner, learning 
for himself, must have recourse to the advice which books 
offer him, and as at present we have not sufficiently re- 
ferred to the different applications of photography, we 
shall give some information respecting the various modes 
of operation which are necessary for photography in 
travel, instantaneous photography, and some special 
branches of the art. 

Outdoor PhotograpJiy. — The travelling apparatus 
differs from that of the studio ; it is much lighter and 
more portable. The camera is much smaller and is 
furnished with a bellows which can be extended and con- 
tracted at the will of the operator. It is supported on 
a tripod stand, the feet of which fold up, or slide in 
grooves. It is furnished with straps which secure almost 
all the apparatus, including a tent to serve as a dark 
room. The whole can be easily adapted to the shoulders 
of the tourist, so that he may thus carry his complete 
material without fatigue. (See fig. 32.) 

The lens^ screws on to the camera, so that it may be 
carried separate. This lens is simple, that is to say it 
consists of but one achromatic lens, sufficient for photo- 

' In England view lenses are manufactured in great variety, 
double and single wide angled, with short focus, and others with a more 
contracted field and longer focus. Many lenses, such as those of Ross and 
Dallmeyer, are deservedly famed all over the world. — Ed. 



136 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

graphs of views and monuments. We specially recom- 
mend the orthoscopic lens invented at Vienna. It con- 
Fig. 32. 




PORTABLE PHOTOGRAPHIC APPARATUS. 



sists of a double combination of achromatic glasses, the 
position of the diaphragms at the back of the lens tube 



THEORY AND PRACTICE. I 37 

permitting the utilisation of almost all the light entering 
through the glasses. Another great advantage it offers 
is that it gives more nearly the true perspective and 
straighter lines in monuments than other lenses. 

As before mentioned, the photographic tourist must 
be provided with a dark tent, which can be procured 
very compact and which need only be large enough to 
take in the upper part of the body. It can be readily 
set up, and contains the silver bath, a rack for the 
various bottles, and a reservoir on the top to hold a supply 
of water for washing the plates, a sink for getting rid of 
waste ; in fact everything which the artist requires. 

The photographic tourist, if he is a good operator, 
will readily be able to produce views of monuments and 
buildings in general ; but if he attacks nature, if he at- 
tempts studies of skies, or tries to fix on his collodion 
the effects of the shadows which adorn the landscape, 
he will encounter difficulties which will prove insur- 
mountable, unless his perseverance is equal to his 
ambition. 

' One of the greatest difficulties of the landscape 
photographer,' says the talented artist, M. A. Liebert, to 
whom we have already referred, * is the production of 
skies with natural clouds, because the light, from its 
great strength, destroys all the cloud shadows by solarisa- 



138 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

tion ; the result is skies whose uniform whiteness pro- 
duces a monotony which deprives the landscape of its 
aerial or natural perspective ; all the delicate tints pro- 
duced by distance and the reflections of the clouds dis- 
appear ; the image thus loses a great part of its artistic 
value. 

* Various methods may be employed for obtaining 
clouds in the sky of a landscape. The first consists in 
operating instantaneously and then reproducing the 
natural sky, which is thus in keeping with the rest of the 
picture ;• but with a little practice in development of 
the image clouds may be obtained. The best way to 
manage the clouds during the development of a picture 
which has been shortly exposed consists in covering the 
glass with a very weak neutral reagent, until the clouds 
are developed ; the rest of the picture is then subjected 
to the ordinary development, care being taken to con- 
fine the solution as much as possible to the landscape 
itself 

'When a picture is to be printed with the sky of 
another negative care must be taken to select a sky ap- 
propriate to the subject in order to secure harmony. In 
such a case it is necessary to bear in mind the effects of 
light, so that the clouds and the picture may be alike as 
regards the light. The horizon lines should keep their 



THEORY AND PRACTICE. 1 39 

character, the sky which is less distinct in the distance 
gradually becomes more definite in the higher parts of 
the picture. These delicate operations require great care 
and taste, and, above all, artistic feeling.' 

The same artist gives excellent advice to the land- 
scape photographer, and with good right claims the title of 
work of art for a picture obtained under good conditions. 

* To give the true artistic effect of a landscape, it is 
important to discover that view of it which presents the 
greatest harmony in its tout-ensemble, and to choose 
the time of day when this view is in the best light for 
reproducing its objects in their true significance and 
character, and when the effects of light and shade are in 
keeping with form and distance. 

' Thus it will be seen that great taste and judgment 
are required to produce a picture really worthy the name 
of a photograph, and this applies equally to portrait as to 
landscape work. Unfortunately for the beautiful art it 
is often enough disgraced by distorted effects in black 
and white, which have as little right to the title of pho- 
tographs as their producers to that of photographers.' 

By repeated improvements in the lens and the various 
solutions employed, the time of exposure has been re- 
duced to the fraction of a second, so that it is possible 
to obtain photographs of a horse in full gallop, a pass- 



I40 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

ing regiment, a wave just breaking, or a flying cloud. 
The collodion for instantaneous pictures should be very- 
fluid. This collodion is sensitised with iodide of lithium 
and bromide of lithium. The silver bath of 8 parts of 
silver to lOO of water is saturated with iodide of silver, a 
few drops of nitric acid are added, and the coated plate 
is allowed to remain in this bath for five minutes. By 
this means the maximum of sensibility is obtained. 
The developing solution is made of sulphate of iron 
to which acetate of lead, formic acid, and nitric ether 
have been added.^ 



• It is impossible in a work like this to give a detailed account of the 
various instantaneous photographic processes. They all present difficulties 
of manipulation which can only be overcome by the experienced operator. 
—Ed. 



141 



CHAPTER V. 

RETOUCHING. 

ACCIDENTS WITH NEGATIVES AND PROOFS — METHOD OF REMEDYING 
THE SAME — RETOUCHING THE NEGATIVE — IMPERFECTIONS IN THE 
POSITIVE— RETOUCHING PHOTOGRAPHIC PROOFS WITH INDIAN INK 
— COLOURING PHOTOGRAPHS— PHOTOGRAPHIC CARICATURES. 

In spite of every precaution on the part of the operator, 
the photographic negative, as well as the positive proof, 
are often imperfect. Unforeseen and often inexplicable 
accidents frequently mar work which has cost much 
time and trouble. 

A few seconds' over-exposure, the development pushed 
a little too far, the slightest impurity finding its way into 
any of the reagents employed, a ray of light — any one of 
these is sufficient to spoil the picture, cover it with a 
cloudy fogginess, puncture it with pin-holes, or mark it 
with lines which destroy the purity of the drawing. 

Pin-holes and small spots on the negative often arise 
from badly cleaned glasses. If there happen to be a few 
grains of Tripoli powder or a few dust spots on the plate, 
the collodion coating will make them apparent however 



142 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

minute ; they will prevent the developer acting on the 
spot they cover, and will form very visible marks in the 
proof. 

Transparent pin-holes in a negative can be touched 
out with Indian ink slightly gummed. 

Imperfections in the positive proof can be corrected 
by careful touching with Indian ink to which a little 
gum and carmine have been added. 

The photographic proof can be used by the artist as 
a sketch on which he can work with his pencil or brush, 
and is thus transformed into a miniature or crayon. 

Protests against the use of pencil or brush on the pho- 
tographic proof have not been wanting ; in the Third Part 
of this work we shall consider the system of retouching 
from the artistic point of view ; for the present we shall 
only regard it in a purely practical light. 

The retouching a positive proof with Indian ink 
should be done before the operation of rolling ; it is very 
rare, we repeat, that this retouching is not necessary, 
especially in portraits. The sitter often moves his eyes, 
which prevents their appearing sufficiently distinct and 
sharp in the photograph ; the draperies do not always 
present enough vigour in shade. A few delicate touches 
with a brush easily repair these and similar imperfections. 
It is often necessary to retouch the whites of a picture 



^RETOUCHING. 143 



which appear too much like pure blots without shade or 
half-tones. A man's shirt nearly always prints like a 
white triangle, without folds and without trace of studs, 
and thus produces a lamentable result in the midst of a 
picture which may be otherwise perfect. A touch of 
Indian ink or sepia with a fine brush will soon remedy 
such defects. 

Photographs intended to be coloured with crayon or 
water colours should be printed on plain salted paper. 
These coloured proofs rarely look well ; and oil-painting 
on the positive also gives but a poor result. In the latter 
case the proof is printed on canvas. We shall, however, 
see that the photographic art is capable of rendering 
great service to painters of the greatest talent. \{ painted 
photographs are held in but little esteem it is because 
they mostly owe their origin to coloiirers rather than to 
real artists, and because they are destined for slender 
purses demanding six portraits for six shillings. But, it 
seems to us, in a great many cases that the photograph 
might very well serve as the sketch for the painter. It 
is to be regretted that good artists do not oftener make 
use of it. 

F^g- 33 represents a photographic caricature which is 
obtained as follows. To represent a large head on a 
small body a picture of the head alone is first taken and 



144 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

then a picture of the entire body on a much smaller 
scale. Proofs are taken on paper from the two nega- 
tives, and then the large head is cut out and pasted on 

Fig- 33- 




PHOTOGRAPHIC CARICATLRE. 



to the shoulders of the figure on the smaller scale. If 
the large head does not fit very well on to the small body 
the neck is touched up with a brush. A photograph is 



RETOUCHING. 1 45 



then taken of the picture thus obtained, and the negative 
produced will furnish any number of caricature proofs. 

Similar processes to that just described are often 
made use of for the production of political photographs. 
A new ministry comes in, and in a day or two photo- 
graphs are on sale everywhere of its members in council. 
It is certain the august body has not devoted one of its 

* sittings ' for the purpose of being photographed. How 
then is the picture obtained ? Nothing more simple. 
Some enterprising photographer seats a number of his 
friends round a large table covered with a green cloth ; 
on a background a handsome marble mantelpiece and 
a splendid chandelier are painted to represent the 
ministerial room. He takes a photograph of this scene, 
obtains a positive proof on paper, cuts out the heads of 
the models, and inserts in their places the heads of the 
new ministers cut from their carte-portraits. After 
being touched where necessary with the brush, a new 
photograph of this composition is taken and the thing is 
done. The interview between Bismarck and Thiers was 

* photographed ' in this way. 

Photography offers, indeed, a mine of pleasant diver- 
sions for the observer ; but we shall not go into this 
branch of the art which we are studying from a practical 
point of view. 

L 



146 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

We can only add, to keep within the limits of this 
chapter, that careful artistic retouching helps to improve 
the photograph by giving the portrait the true aspect of 
the human face J 

* Madame de Stael,' says our witty writer M. Legouv^e, 
' died talking ; for several days her relatives seeing the 
fatal end approaching endeavoured in vain to keep 
visitors from her bed of agony : " Let them come in, let 
them come in," she cried in a feverish voice ; " I thirst for 
the human face ! " This profound and almost terrible 
saying expresses one of the most ardent passions of our 
time ; we have all a thirst for the human face. Stop 
before an exhibition of photographs or prints, watch the 
crowd which presses round, and note its inquisitive 
attention. ... Is this pure curiosity > Simple love of 
diversion ? Frivolous idleness ? No. . . . We thirst for 
the human face, because we thirst for the human mind.* 

The desire thus referred to by M. Legouve is real, 
and certainly no one would question its bearing on pho- 
tography ; therefore we say to the retouchers : * Give us 
the human face.* 

• This would almost seem to be a left-handed compliment to photography 
if the author had not already convinced us of his profound admiration of the 
art and its capabilities. For my own part I think that photography in the 
hands of a skilled and artistic operator is capable of producing results 
which can never be improved by retouching. — Ed. 



147 



CHAPTER VI. 

ENLARGEMENT OF PROOFS. 

APPARATUS EMPLOYED FOR ENLARGING NEGATIVE PROOFS — WOOD- 
WARD'S SYSTEM — MONCKHOVEN'S APPARATUS — UNIVERSAL SOLAR 
CAMERA. 

It often occurs that photographs of the natural size of 
objects are required. But to obtain a large negative, 
say a yard square for example, by the ordinary process 
is next to an impossibility. How could a plate of such 
a size be properly cleaned, how coated with collodion, 
how could the developing liquid be applied ? ^ By the 
usual processes it may be said that such manipulations 
would be completely impossible even to the most expert 
operator. 

' Plates a yard square and even larger are manipulated by the Auto- 
type Company and other photographic firms in London. — Ed. 

L 2 



148 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

The best means of obtaining a picture approaching 
the natural size of the object seems to consist in the 
enlargement, by optical apparatus, of a small negative 
which has been obtained as perfect as possible. 

The ordinary method of enlarging consists in pro- 
jecting the image of a negative plate by means of the 
lens of a megascope on to sensitised paper, where it is 
fixed. The Image, enlarged like that of the magic 
lantern slide, is faithfully reproduced on the photographic 
paper. 

Though the theory of this operation is simple enough, 
its practice is somewhat difficult and requires a \^xy per- 
fect instrument. Mr. Woodward's apparatus consists of a 
large wooden case containing the negative, the image of 
which is powerfully illuminated and projected with the 
required degree of amplification on to the photographic 
paper. 

M. Monckhoven has improved this system by adapt- 
ing a second lens to the megascope which corrects the 
spherical aberration. The negative is held in a frame 
(fig. 34), the enlarging lens is contained in a metal tube, 
and the enlarged image is thrown on a screen at some 
yards' distance from the apparatus. 

The illustration (fig. 34) shows the general appear- 
ance of the apparatus. On the right of the drawing will 



ENLARGEMENT OF PROOFS. 



149 



be seen a thin partition 
which separates the 
operating room from 
the outer air. This 
room should be ex- 
posed to the south. The 
enlarging camera is 
fixed to an opening in 
the partition, through 
which a powerful light 
is thrown by means of a 
reflector which follows 
the sun outside, and 
transmits the rays 
through a large lens 
which condenses them 
on to the glass nega- 
tive to be enlarged ; 
after passing through 
the negative it next 
traverses the enlarging 
lens, carrying with it 
the image to be repro- 
duced, and thrown in 
the required size upon 




150 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

the screen fixed at some yards' distance.^ This distance 
should be about three yards to obtain a photograph 
one yard in diameter. 

Fig- 35- 




LI^BERT'S enlarging APPARATl'S. 



M. Liebert has invented an enlarging apparatus 
which has advantages over the preceding. It is much 
more economical and does not require any special 



' The size of the enlarged image also depends on the focal length of 
object-glass. — Ed. 



ENLARGEMENT OF PROOFS. 151 

fixed position. It can be used from sunrise to sunset, 
which is not the case with the apparatus illuminated 
by reflection which we have just described. The illus- 
tration (fig. 35) gives such a clear idea of Liebert's appa- 
ratus that any description is unnecessary. 

Success in the enlargement of photographs can only 
be obtained when the greatest attention has been paid 
to the preparation of the small glass negative, which re- 
quires a special method. 

A thin, quite transparent glass plate should be chosen 
with a perfectly smooth surface. Liquid collodion must 
be used, to ensure sufficient transparency to the image 
to be enlarged. 

The negative must be very transparent; therefore 
it should not be too vigorous or intense. To arrive at 
this result such substances are avoided in the preparation 
of the developer as tend to intensify. The sulphate of 
iron solution in alcoholised water is alone sufficient. 

The negative having to be exposed to the sun's rays 
should not be coated with any varnish which melts under 
the action of heat. 

The art of enlarging photographs has been brought 
to great perfection during the last four years.' Some 

* The enlargements obtained in London by the Autotype process appear 
to me to leave almost nothing to be desired. The method followed in their 



152 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

operators have arrived at results worthy of the highest 
praise. 

Enlargements, it is true, offer certain inconveniences; 
the details of the enlarged proof have often a disagree- 
able effect ; they are exaggerated and seem as though 
seen under a magnifying glass. It would, however, be 
unjust, in spite of these defects, to underrate the im- 
portance of the results obtained. 

production is totally different from any of the processes described by the 
author. The most beautiful carbon transparencies are first taken from 
small negatives, and are used in" the production of large negatives on glass 
plates by the wet collodion process. — Ed. 



153 



CHAPTER VII. 

PROCESSES. 

THE DRY-COLLODION PROCESS— EMPLOYMENT OF ALBUMEN, HONEY, 
AND TANNIN — WAXED-PAPER PROCESS— PERMANENT PHOTOGRAPHY 
BY THE CARBON PROCESS— METHODS OF POITEVIN, SWAN, ETC. 

The wet-collodion process, which we have described at 
some length, gives excellent proofs, very sharp, and often 
of an astonishing degree of perfection ; but it has one 
great drawback. As soon as the glass plate is coated 
with collodion it must be at once exposed in the camera. 
If it is allowed to dry, it is no longer so impressionable. 
As the collodion dries very rapidly it is very difficult to 
make use of it in landscape work, or in any way in warm 
climates.^ 

' My own experience when travelling in the tropics does not bear out 
the author's views on this point. Dry plates as we find them now-a-days, 
nearly, if not quite equal to wet plates in their sensitiveness, are greatly to 
be desired by the photographer who may happen to be exploring a new 
country. Yet I have found the old wet collodion process in the tropics 
always so ready and always so capable of responding to my every wish, 
that I esteem it above all others. By certain simple modifications, such 
as adding alcohol to the collodion, a wet plate may be freely exposed for 
half-an-hour in a climate where the temperature is 90° in the shade. — Ed. 



154 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

It had long been the endeavour of photographers 
to discover a means by which plates coated with collo- 
dion and allowed to dry could still be made to retain 
their sensibility to light. The problem has been solved 
by the addition to the collodion of gummy or resinous 
matters, so that instead of the film being impervious, it 
should, on the contrary, remain porous, so as to absorb 
the sensitising liquid when required for use, a few mo- 
ments before its exposure in the camera. 

Dry collodion. — The reader will remember that albu- 
men was employed in photography until the discovery 
of collodion. It \^ still made use of by some ope- 
rators in certain cases, and gives very good results. 

' TJie albumen pi'ocess. — A well cleaned glass plate is 
coated with ordinary iodised collodion ; after being 
sensitised and washed to remove free nitrate of silver 
the collodion is again coated with albumen containing 
iodide of ammonium, ammonia, and sugar candy. 

The plate thus covered with a liquid which preserves 
the collodion beneath it is dried and then placed in a 
grooved box which is perfectly air-tight. When the 
plate is required for use, it only remains to sensitise it 
in the silver bath, and the concluding operations of 
washing and drying are effected in the ordinary way. 

The time of exposure in this process is somewhat 



PROCESSES. 155 



long ; to obtain good results the directions of its inventor, 
M. Taupenot, must be scrupulously followed. 

The cleaning of the glass requires to be even more 
carefully done than in the wet-collodion process. After 
spreading the collodion on the plate, it is sensitised in a 
neutral nitrate of silver bath. The plate is drained and 
then recoated with the preparation of albumen or white 
of egg. To prepare the latter it is sufficient to pour 
some whites of eggs into a glass, and after adding a few 
drops of ammonia and a little iodide and bromide of 
ammonium, to beat up the mixture well. The addition 
of sugar candy is useful ; it keeps the albumen fluid, and 
allows of its being easily spread over the plate as* with 
collodion. The plate once albumenised is dried, away 
from light and dust, and may be used very advan- 
tageously five or six hours after being prepared. 

A number of plates are prepared in this way, and 
when required for use they are sensitised in a nitrate of 
silver bath to which a little acetic acid has been added. 
They are developed with gallic acid, and fixed with hy- 
posulphite of soda. 

The albumen process necessitates a considerable ex- 
posure in the camera ; the development is not produced 
until the plate has been under the action of the develop- 
ing fluid for about half an hour. It cannot be employed 



156 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

for portraiture, but is well adapted for reproducing 
drawings, pictures, and engravings, as the albumen gives 
a very sharp negative full of harmony in tone. 

TJie tannin process. — This process, which has been 
much spoken of, is due to Major C. Russell. Thanks to 
the persevering and ingenious experiments of this sav^ant, 
it is now possible to preserve the prepared plates for a 
very long time without their losing any of their pro- 
perties. Their sensibility is certainly much more con- 
siderable than that of plates coated in the ordinary way. 
Major Russell's discovery consists in combining tannin, 
or tannic acid, with the coating of iodide of silver, des- 
tined to be impressed with the light. The original pro- 
cess, which was published in 1 861, has undergone con- 
siderable modifications since that time ; we shall describe 
it with the improvements which have been successively 
made.^ 

* The tannin process is here singled out as a type of a host of other 
dry-plate processes which are interesting as forming links in the chain of 
photographic progress. An endless variety of substances may be used in 
place of tannin more or less successfully. Thus I myself, when I could 
obtain nothing better, have employed a solution of lime-juice, orange-juice, 
and, with varying success, ordinary bottled beer with a slight admixture 
of sugar. But the most modern processes, although they demand delicate 
manipulation, yet in their rapidity of action and beautiful results are 
nearly on a par with our best wet-collodion processes. As this work does 
not profess to furnish exhaustive descriptions of the various processes, I 
need do no more than give an outline of one or two of the newest methods 
of preparing dry plates, which do away with the use of the nitrate of 
silver bath — El). 



PROCESSES. 157 



The plate is first coated with a special collodion 
containing small quantities of iodide of cadmium and 

Gelatino-bromide process : — 

To I ounce pure gelatine add 16 ounces of water. When the gelatine 
has absorbed the water to its fullest extent, dissolve by gentle heat, and 
while the solution is yet hot add i\ ounce bromide of potassium, stirring 
the mixture until the salt is thoroughly taken up. Dissolve | ounce nitrate 
of silver in water, sufficient to make a saturated solution, which must then 
be next added to the bromadised gelatine. The addition of the nitrate of 
silver renders the solution highly sensitive to light. This and the subsequent 
operations must therefore be conducted in the yellow non active light of 
the operating room. This sensitive emulsion which alone forms the dry- 
plate film must be subjected to a process of washing so as to remove the 
free salts of the metals, which would otherwise interfere with the picture. 
This may be done by allowing the gelatine to set, cutting it up in small 
pieces and washing it in water kept running for some time, until, indeed, 
all traces of the free salts have been removed, and the emulsion carries only 
the quantity with which it has formed an intimate union in the production 
of bromide of silver. The sensitised gelatine may now be dissolved by 
gentle heat, and poured in quantum siifficit on the centre of a glass plate 
over which it is evenly distributed, placed on a level stand on a dark shelf 
free from dust, where it is allowed to set and dry". When dry, the plate 
thus prepared is ready for exposure in the camera, and if carefully pre- 
served from daylight weeks may elapse between the time of preparation 
and exposure, and exposure and development. I have seen plates taken by 
this method almost instantaneously, but the nice timing of the exposure 
has hitherto proved a drawback to the wide application of the process. 
After exposure the plate must be soaked for some time in water, when the 
latent image may be brought out by what is kno^vn as 'alkaline develop- 
ment,' discovered by the inventor of the tannin process. 

Developer, No i. 

Carbonate of Soda 40 grains. 

Water Lpint. 

No. 2. 

Pyrogallic Acid ....... 96 grains. 

Alcohol I ounce. 



158 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

iodide and bromide of ammonium. It is sensitised in a 
bath of nitrate of silver strongly acid with acetic arid. 
The plate as soon as sensitised is well washed, then 
coated with a solution of tannin (lO parts of alcohol 
and 2^ to 3 of tannin to the lOO of water). This solu- 
tion is poured over the plate several times, which is then 
washed and dried in the plate rack. It is hardly neces- 
sary to say that these operations take place in the dark 
room ; when the plate is dry it is slightly warmed, and 
can then be kept for a very considerable time. 

The time of exposure of these tannin plates varies 
from about 35 seconds to 2 minutes. Before developing 
the image, the plate is dipped in a weak solution of 
nitrate of silver till the tannin coating is impregnated. 



No. 3, 



•Bromide of Potassium 
Water 



5 grams. 
I ounce. 



No. I is the alkaline solution which is used with the addition of a few 
drops of Nos. 2 and 3, in quantity sufficient to flood the plate. The time 
of exposure and development must be determined by the experience of the 
operator. 

Collodion Emulsion process : — 

This process, while it offers more uniformity and certainty in its results, 
is not so sensitive as that just described in which gelatine takes the place of 
collodion. With the exception of collodion, ihe materials used and the 
mode of manipulating the plates are almost identical with those employed in 
the gelatino-bromide process. The reader who is anxious to study the 
collodion emulsion process will find detailed descriptions in the British 
yournal Photographic Almanac for 1875. — ■^^- 



PROCESSES. 159 



It is then drained and the picture developed with a solu- 
tion of pyrogallic acid and water, and a little alcohol 
and glacial acetic acid. If the image requires intensi- 
fying, a weak solution of citric acid mixed with a small 
quantity of nitrate of silver added to the developer will 
give excellent results. The plate is then well washed 
and fixed as usual with hyposulphite of soda. 

M. Legray is the inventor of the waxed -paper pro- 
cess — an interesting and useful process, of which the 
following is a succinct description. 

The paper which is to be coated with wax must be 
formed of a uniform and homogeneous pulp, well-sized, 
and must be thin, as the proof has to be seen by trans- 
mitted light. The operation of waxing is very delicate. 
The paper is spread out on a metal box filled with boil- 
ing water, which is maintained at 100° by placing it 
on a fire. The leaf of paper is protected from con- 
tact with the metal by intermediate sheets of blotting 
paper ; it is then rubbed with white wax which sinks in 
as it is spread. As soon as the first leaf is well impreg- 
nated all over its surface, a second sheet of paper is 
placed on it, and rubbed with wax in the same way, then 
a third, a fourth, and so on till twelve have been done. 
These twelve waxed sheets are interleaved with 
twelve unwaxed sheets, and then the whole packet is 



l60 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

energetically rubbed first in one direction, then in 
another. The excess of wax in the twelve sheets 
prepared passes into the other twelve sheets, thus giving 
twenty-four sheets saturated with wax. Each leaf is now 
rubbed separately, one by one, with a silk rubber, and 
when a well-rubbed leaf is smooth, transparent, and 
does not exhibit white or brilliant spots, indicating a 
want or excess of wax, it can be kept for an indefinite 
time. 

The waxed papers thus obtained are plunged into a 
solution of iodide of potassium in rice and water.^ When 
removed from the bath and dried, they are placed be- 
tween two sheets of blotting paper, and rubbed warm 
with a hot iron. 

The iodised waxed paper has a violet tint ; it must 
be preserved from contact with damp or air. When 
it is required to sensitise the paper before use, it is 
plunged in a bath of nitrate of silver to which acetic acid 
has been added.^ 



' To 35 oz. of Water, 

i,ooo grains of Rice. 
750 ,, ,, Sugar of Milk. 
225 ,, ,, Iodide of Potassium. 
75 ,, ,, Bromide of Potassium. 

2 Distilled Water i ounce. 

Nitrate of Silver 30 grains. 

Glacial Acetic Acid 40 minims. 



THE CARBON PROCESS. l6l 

The paper is exposed in the camera by being fixed 
between two glass plates. The time of exposure is usually 
about one hour, sometimes more ; it can only be de- 
termined by experience. 

The development of the picture is accomplished by the 
aid of gallic acid, to which nitrate of silver and acetic 
acid are subsequently added. The leaf of paper is com- 
pletely immersed in the developing bath until it has 
acquired the desired intensity. 

It is fixed as usual with hyposulphite of soda. 

When washed and dried the paper is rendered again 
transparent by rubbing with a hot iron, after being 
covered with a piece of tissue paper. 

Besides M. Legray, Messrs. Vigier, Baldus, and others 
have prepared albumenised and gelatinised papers which 
give equally good results, and as formulae for obtaining 
negatives on waxed paper abound, we refer the reader 
who may be curious in this regard to the published works 
of these inventors. 

The permanent carbon process. —The processes we 
have hitherto described furnish prints more or less 
liable to fade. Whatever the cares and precautions of 
the operator, however well it is washed, the positive 
proof is destined after a certain time to tarnish, to 

M 



1 62 OPERATIONS AND PROCESSES OF PHOTOGRAPHY 

become yellow, and even to disappear. How, indeed, 
could it be otherwise, when it is formed by the reduc- 
tion of metallic salts, made up to a certain extent of 
fugitive chemical agents. This serious drawback gave 
rise to the desire for some means of imparting dura- 
bility to the photograph, and to assure it the same per- 
manency as typographical proofs and impressions in 
general which are obtained with an ink made with some 
permanent basis, such as carbon. &c. 

The term carbon print is applied to photographic im- 
pressions obtained by the aid of some fixed or unalterable 
matter, carbon or other permanent mineral substances. 
The various processes for producing positive carbon 
prints are based on the principle indicated by Alphonse 
Poitevin in 1855. 

This learned experimentalist, of whom we shall have 
to speak further in our chapter on Heliography, and to 
whom the photographic art is indebted for a great num- 
ber of most important improvements, discovered that the 
action of light on gummy or mucilaginous matters mixed 
with alkaline or earthy bichromates renders them in- 
soluble, even in warm water : it then occurred to him, for 
the purpose of producing permanent photographs, to add 
some insoluble colouring matters, such as carbon or pow- 



CARBON PRINTING. 163 



dered enamels, to gelatine, albumen, gum arable, sugar, 
starch, &c.^ 

A fine coating of bichromatised gelatine, mixed 
with carbon, is spread over a leaf of paper and exposed 
to the impression of the light through a negative. After 
the insolation, the paper is washed in tepid water ; the 
parts of the picture unaffected by the light {i.e, those 
parts which have been protected by the denser portion 
of the negative) are dissolved, whilst those parts which 
have been rendered insoluble by the action of light re- 
main adhering to the surface, and the picture ^appears, 
formed by the insoluble parts of the mucilage. Since 
this first indication of the process by M. Poitevin, 
published more as a curiosity than as a practical 
method, a great number of operators set themselves to 
study the new phenomena brought to light. Laborde, 
Gamier, and Salmon at Paris, Pouncy at London, and 
others, were not long in- conceiving similar processes to 
that of M. Poitevin, all of them more or less perfect. In 
1864, Mr. Swan gave a vigorous new start to the art of 
permanent carbon photography ; and shortly afterwards, 
Mr. A. Marion popularised the new process by some 
truly remarkable productions. 

' Photographic au charbon. Recueil pratique de divers procedes des 
epreuves positives formees de substances inalterables, par L. Vidal. Paris. 
1869. 

M 2 



1 64 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

The following extract from the Moniteur de la Pho- 
tographie describes Mr. Swan's curious process : — ' In 500 
cubic centimetres of cold water, allow 1,800 grains of 
gelatine to swell for some hours, then dissolve with a 
gentle heat Add a white of ^^^ beaten up, stir well 
and heat till it boils, and then filter. By this means the 
albumen is clarified and becomes brilliant and limpid. 
The amount lost by evaporation is made up with water, 
and 900 grains of white sugar added. Indian ink as 
colouring matter is now mixed with it, after being pow- 
dered or dissolved in water. The gelatine is kept in well 
stoppered bottles. To sensitise it, a solution of bichro- 
mate of ammonia (450 grains to 1,350 of water), is pre- 
pared and added to the coloured gelatine in the propor- 
tion of 450 grains to 3,000 or 4,500 grains of gelatine. A 
glass plate is next coated with non-iodised collodion of a 
proper consistency : this, being evenly spread over, is 
allowed to dry perfectly. The plate is now warmed and 
coated very evenly with the sensitised gelatine solution, 
which soon sets ; when quite dry, this film can be detached 
by passing a penknife along the edges, and presents the 
appearance of a piece of varnished leather, black in colour, 
and flexible. It is nevertheless translucent, and by exami- 
nation, it is easy to determine if it is of a proper colour. 
This film must be kept in the dark, and employed within 



swan's process. 165 

one or two days. To print on it, it is placed in contact 
with the negative, the collodion side next the film, so that 
by exposure to the light the impression is formed on the 
inner face of the sensitised gelatine. The time of exposure 
naturally varies according to the intensity of the light, 
and the density of the negative ; but, in any case, it will 
not exceed the third or the fourth of that required with 
the nitrates of silver. The range is much larger than 
with the ordinary processes, and prolonged exposure 
does not materially affect the picture. The print is then 
mounted on paper with starch or india-rubber. When 
dry it is plunged into water, heated to 40° Centi- 
grade. The gelatine unaltered by the light soon dis- 
solves, leaving the picture with all its gradations of tone 
adhering to the collodion. When the print has soaked 
for about two hours it can be fastened to another sheet 
of paper, to straighten it, and when dry the first sheet 
may be readily removed. The print when finished 
possesses great delicacy, and is of course glazed with 
the film of collodion in front' ^ 

' Carbon prints taken by the above process are as fine in gradation, 
vigour, and sharpness as the best silver prints. There seems, however, 
to be some risk of their destruction, in consequence of the collodion film 
cracking. The process is patented (No. 503, February 29, 1864). Some 
specimens submitted to the public by the patentee are not inferior to the 
very finest photographs upon paper that have ever been seen. Tht Dictionary 
of Photography. Low & Co. 1867. 



1 66 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

Since Mr. Swan's innprovements the so-called carbon 
processes have made great strides, and admirable results 
have been arrived at. According to the nature of the 
permanent and solid substance which is incorporated 
with the gelatine, the glazed tissue can be toned black 
like an engraving, purple, or sepia colour. 

The colouring matter, of whatever nature it may be, 
is first ground to an impalpable powder, and the gelatine, 
dissolved in warm water and well filtered, is added in 
small doses (3,000 grains of gelatine to the litre of 
water = 176 pint). The mixture is then stirred till per- 
fectly homogeneous. 

A sheet of paper of good quality is next damped 
and placed on a glass plate in such a way that by the 
means of four small rules the four edges of the paper 
can be turned up to the extent of not more than three 
or four millimetres, a very shallow dish being thus 
formed, into which the gelatine solution is poured so as 
to flow perfectly horizontally. The solution soon solidi- 
fies : the gelatine film is then lifted from the glass and 
allowed to dry spontaneously. 

The gelatine films are sensitised by immersion in 
an aqueous solution of bichromate of potassium (of 
5 p. 100). To take an impression, one of them is 
applied to the back of a photographic plate, and is then 



IMPROVEMENTS IN CARBON PRINTING. 1 6/ 



exposed to the light. When a negative is used to print 
from, the picture will be reversed, and it is for this 
reason that a provisory support should be employed, 
which can be easily taken from the positive picture 
when desired. We refer the reader who may wish to 
master all the details of this process to Mr. D. B. Monck- 
hoven's work,^ only allowing ourselves to give here the 
principle of a new branch of the art which we are study- 
ing. The practical details would take us too far from 
our plan, which comprehends all the numerous chapters 
of the book of modern photography.^ 

' Published by G. Masson. Paris, 1873. 

"^ The carbon process, in its most recent fonns, has attained to that 
degree of perfection, certainty, and facility of manipulation which renders 
it a most formidable rival to silver printing. Photographers have not 
been slow to acknowledge its superiority over all other processes in the 
production of the most delicately beautiful enlargements from small nega- 
tives. But it is only within the past month or two that the carbon process 
has proved capable of producing small prints equal in every way to the 
best silver prints. 

In common with all the other permanent photographic printing processes, 
whether the proofs are obtained by exposure to sunlight or mechanically, 
the carbon process starts from the basis supplied in the insolubility resulting 
from the exposure to solar light of a mixture of gelatine and bichromate of 
potash. But in order to render this chemical action available for the pur- 
poses of the carbon printer, the gelatine and bichromate of potash must be 
charged with some permanent colour in a fine state of division, us in Swan's 
process. In place, however, of employing collodion as the support for the 
tissue, the Autotype Company at Ealing Dean simplified the method 
of producing tissue by using paper as the support and by introducing 
machinery into its manufacture. This company held various patents which 
have been transferred to Messrs. Spencer, Sawyer, Bird & Co., to whom 
we are mainly indebted for rendering the carbon process of practical 



1 68 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 



commercial value. They now manufacture tissue of all shades of colour, 
ready for the simple operation of sensitising ty floating on a solution of 
bichromate of potash. While confining my observations to one or two 
topics relating to carbon printing, I must refer the reader for detailed 
information to the manual of practical instruction published by the above 
firm. 

A carbon print may be taken from an ordinaiy negative by exposing 
the sensitised tissue beneath the negative as in ordinary silver printing. 
No visible image will result from this exposure : the image is nevertheless 
imprinted in the tissue, or rather, the light has imparted to the surface 
various degrees of insolubility, which, in their intensity, correspond exactly 
with the shadows and half-tones of the picture. In other words, where 
the action of the light is strongest, the sensitive film elects to form a close 
and indissoluble union with the carbon. , When the light has only partially 
affected the tissue the union is weak, and it readily, when treated with 
warm water, yields up part of the colouring matter, and where the light has 
not exercised its subtle influence in the faintest degree, the colouring matter 
may be dissolved out, leaving the paper white. 

The printing of the picture must be timed by the use of a simple 
actinometer made for the purpose. In order to develop the print it is 
necessary to immerse the tissue in a bath of water and to place it in intimate 
contact with a sheet of transfer paper. The tissue and its new support are 
then laid in a bath of tepid water, when the original support will float off 
and the picture gradually reveal itself. This simple operation of washing with 
water removes all the free unaltered carbon, and leaves a bright and beautiful 
impression on a permanent support. In the case of negatives which are 
not reversed, a double transfer must be effected by placing the tissue for 
development on a temporary support of glass or zinc. Specially prepared 
tissue, mounted and developed on a glass plate, not only produces a trans- 
parency full of the most beautiful gradations of light and shade, but so 
exceedingly minute in its details as to enable the operator to take from it a 
perfect negative, enlarged to three or four times the diameter of the 
original. I know of no other transparency to be compared with it in the 
making of large negatives from small ones. 

This peculiar adaptability of the carbon transparency for copying or 
enlarging negatives has rendered it of the greatest value, as it enables the 
carbon printer to make a reversed negative so absolutely identical with the 
original as to permit him to print his proofs by single transfer. — Ed. 



169 



CHAPTER VIII. 

PROBLEMS TO BE SOLVED. 

THE FIXING OF COLOURS — A MYSTIFICATION — EDMOND BECQUEREL'S 
EXPERIMENTS — ATTEMPTS OF NIEPCE DE SAINT-VICTOR AND 
POITEVIN— PHOTOGRAPHIC PRINTING. 

We have seen how and by what processes th(? photo- 
graphic art arrived at fixing the image of the camera on 
paper : the results obtained, though marvellous as they 
are, are susceptible of being improved, like all human 
work. We think it will be interesting if we glance at 
some of the improvements which it is possible to hope 
for in a near future. 

Photography reproduces nature ; the picture which it 
furnishes is the image of the mirror, but the image with- 
out colour. To find a photographic process susceptible 
of giving coloured proofs, and capable of reproducing 
the colours as it does the aspect and form of natural 
objects, would seem to be the criterion of photographic 
power : on the face of it, the problem appears insoluble. 
It is not necessary to be versed in the study of physics 



170 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 



to understand the difficulties in the way. It is necessary 
to find a substance which should be influenced in dif- 
ferent ways by the different rays of the spectrum, and 
which could reproduce the proper colour of each 
luminous ray ; the search for such a chemical as this 
would seem to be comparable to that for the philoso- 
pher's stone. However, in the presence of certain facts 
already obtained by some savants of note, it would be 
imprudent to deny the possibility of such a problem ; its 
solution is perhaps nearer than we are in the habit of 
supposing. A few lights are already shining in the 
direction of this goal, hidden in the bosom of the 
unknown. Will they be useful or fruitless ? Will they 
open up a new road or remain isolated and sterile } 
Until we have passed in review the results already 
obtained we cannot reply. 

It may be well, before studying the real experiments 
made by some of our most eminent scientific men, to nar- 
rate one or two facts, interesting from an historical point 
of view, which made a great stir at the time. In 185 1, the 
photographers of Europe were all thrown into a state of 
excitement by an extraordinary announcement which 
came from the other side of the Atlantic. The 
American papers affirmed that a Mr. Hill, a photo- 
grapher, had discovered the means of reproducing the 



PHOTOGRAPHS IN COLOUR. 171 



images of the camera with their natural colours. For the 
time nothing was spoken of but this illustrious inventor, 
and for the moment his name became as renowned as 
that of Daguerre. This Mr. Hill was a reverend pastor 
who was no enemy to puffing : he had launched the 
news of his invention in all the American papers, and 
had nothing to complain of in the enthusiastic epithets 
which were applied to his discovery. Mr. Hill, all at 
once, soared like a rocket to the topmost steps of the 
ladder of fame. The cute pastor allowed public curiosity 
to ferment well. ' When he saw things were ripe,' says 
Mr. Alexander Ken, who relates the story, * he issued a 
circular promising shortly to publish a work which 
should divulge the secrets of his discovery. The 
author added that this work would only be circulated to 
the extent subscribed for by photographers, and that 
it would be forwarded to all those who sent him their 
address with five dollars. A testimonial, signed by 
several persons, set forth that Mr. Hill was a respectable 
ecclesiastic worthy of all confidence. 

' The circular produced fifteen thousand dollars. The 
volume appeared : it consisted of about one hundred 
pages, and cost the author about twopence a copy. But 
if it was dear, it contained nothing but a few common- 
place descriptions of the well-known daguerreotype 



172 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

process, and said not a word about the reproduction of 
colours ! ' * 

Mr. Hill afterwards published a second and a 
third brochure, but the public had had enough of Mr. 
Hill and his works. The subscribers swore, but a little 
too late, that they would not take them. 

M. Edmond Becquerel was the first who reproduced 
the image of coloured rays. He succeeded in printing 
the seven colours of the solar spectrum on a silver plate. 
His works when made known were appreciated at their 
real value by men of science. M. Becquerel plunged a 
plate of silver in hydrochloric acid diluted with water ; 
he attached the metal to the wire of an electric battery. 
Under the influence of the electric current the silver be- 
came coated with sub-chloride of silver, of a characteristic 
rose colour. On being taken from the bath, washed and 
dried, it was sufficient to expose it to the rays of the solar 
spectrum : the seven colours were then delineated, with 
their corresponding gradations. Unfortunately, up to the 
present no means have been discovered for fixing these 
colours : they disappear when exposed to daylight, and 
must be preserved in the dark. 

' M. Niepce de Saint- Victor also attempted to solve 
this great problem of the fixation of colours, but he-was 

' Dissertation on PJwtography. A. Ken. 1864. 



PHOTOGRAPHS IN COLOUR. 1 73 

foiled in his attempts. He succeeded, however, in 
obtaining photographic proofs of blue, red, and green 
colour. These coloured photographs have a very pretty 
effect. Although somewhat more stable than formerly, 
they are still affected by prolonged exposure to light : 
the processes are, however, already much improved, for 
the proof which M. Niepce obtained at the commence- 
ment of his researches could not stand the slightest ex- 
posure to daylight. It is due to the employment of 
salts of uranium that it has been possible to solve this 
interesting question. 

'To obtain a red-coloured proof, for example, he 
prepared the paper with a solution of azotate of uranium 
of 20 to the 100 of water: this paper is dried in the 
dark, and exposed for a time, varying in length accord- 
ing to the intensity of the light ; the proof is then washed 
in water of 50° or 60° Centigrade, and subsequently 
dipped into a solution of cyanoferride of potassium of 2 
to 100. After a few minutes the print assumes a 
beautiful blood-red colour ; it only remains to wash it 
well in water several times changed and dry it. The 
red print thus obtained becomes green if dipped in a 
solution of azotate of cobalt, and not washed ; the 
green colour appears by drying at a fire ; it is fixed by 
immersion for a few seconds in a solution of sulphate of 



174 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 



iron and sulphuric acid, each in proportion of 4 to 
the 100 of water ; it is then well washed and dried 
at the fire. A violet colour may be obtained by washing 
in warm water as soon as taken from the printing frame, 
and by developing with chloride of gold of ^ to 
the 100 of water. To obtain blue prints the paper is 
prepared with a solution of cyanoferride of potassium of 
20 to the 100 of water ; after exposure under the nega- 
tive it is washed for ten seconds with a solution of 
bichloride of mercury, saturated cold ; a solution of 
oxalic acid at 60° is next applied, and the print is then 
well washed and dried.' ' 

In 1866 M. Poitevin made a series of curious experi- 
ments relating to the grand problem of fixing colours. 
* On a paper covered previously with a coating of violet 
chloride of silver, which he had obtained by exposing 
white chloride to the light, and in presence of a reducing 
salt, a liquid is applied formed of a volume of saturated 
solution of bichromate of potassium, a volume of satu- 
rated solution of sulphate of copper, and a volume of 
solution of 5 to the 100 of chloride of potassium ; the 
paper thus prepared is allowed to dry, and must be kept 
away from light. The bichromate of potassium may be 
replaced by chromic acid, or by azotate of uranium. 

' Annuaire scientifique de M.P.P. Deherain. Paris. 1862. 



PHOTOGRAPHS IN COLOUR. I 75 

With this paper, which is, so to speak, super sensitised, the 
exposure to the direct action of the light is not more 
than from five to ten minutes when it takes place 
through paintings on glass, and one can very well follow 
the appearance of the image in colour. This paper is 
not sufficiently impressionable to allow of its employ- 
ment in the camera ; but, such as it is, it gives coloured 
reproductions in a special enlarging apparatus,' ' - 

These photochromos may be preserved in an album, 
if the precaution is taken of washing them first in water 
acidulated with chromic acid, then in water containing 
bichloride of mercur>^ again in water charged with ni- 
trate of lead; and finally in pure water. In this state, 
they will remain unaltered if kept from the light. 

' The problem of obtaining polychromatic photographs is still far from 
being solved. More enthusiasts than one have imagined that they have 
discovered a clue to the mystery in the beautiful prismatic colours produced 
by a thin film of air imprisoned beneath the collodion of an imperfectly 
cleaned plate. Some eight or ten years ago these aspirants to fame used 
to write to the photographic journals, proudly refusing to confide in the 
public until they had taken such steps as would enable them to engross to 
themselves the entire credit of their discoveries. 

Monochrome photographs may be obtained in a variety of ways, but 
such prints, unfortunately, bring us no nearer to photography in natural 
colours. M. Vidal's prints were probably similar to some I have seen in 
Paris, produced by an ingenious mechanical trick which the photographer 
was in no way careful to conceal. 

As far back as 1810 Seebeck discovered that chloride of silver, when 
subjected to the rays of the spectrum, partook slightly of the different 
colours. Violet produced brown, blue a shade of blue, yellow preserved 
the paper white, and red imparted a red tint to the chloride of silver. - Ed. 



176 OPERATIONS AND PROCESSES OF PHOTOGRAPHY. 

Unfortunately, these new photogenic pictures are 
hardly more stable under the action of light than those 
obtained previously by Messrs. Becquerel and Niepce 
de Saint- Victor.^ 

In the photographic exhibition in the Palais de I'ln- 
dustrie in 1874, a number of polychromic prints were 
exhibited by M. Vidal, which have the advantage of 
being permanent. But the colours affect principally 
the shadows, and are almost invisible in the details. M. 
Vidal employs papers which he superposes to give birth 
to each colour ; but the tints and half-tones are very 
indefinite. 

The result of these curious experiments shows plainly 
that the fixation of colours by photography is one of the 
most difficult problems which modern science has to 
solve. Though but a very short portion of the road 
towards the great end has been opened up, still it 
would be wrong to despise what has been done or to 
regard the final solution as an altogether Utopian or 
chimerical problem. 

As M. Niepce de Saint- Victor says,* If the problem of 
the fixation of colours is not yet solved, one may, at 
least, hope that it will be.' 

' Louis Figuier, Les Mcrveilles de la Scietue. 



PHOTOGRAPHS IN COLOUR. 1 77 

This is evidently one of the greatest questions the 
art of Daguerre has to solve. There is another of high 
import, namely, the transformation of the negative into 
an engraving plate ; we shall refer to this in the first 
pages of our third part. 



N 



179 



PART III. 

THE APPLICATIONS OF PHOTOGRAPHY. 



CHAPTER I. 

HELTOGRAPHY. 

THE DAGUERREOTYPE PLATE TRANSFORMED INTO AN ENGRAVING 
PLATE — DONN6 — FIZEAU — THE PHOTOGRAPHIC ENGRAVING OF 
NIEPCE DE SAINT VICTOR —PHOTO-LITHOGRAPHY AND HELIOGRAPHY' 
INVENTED BY A. POITEVIN — PROCESSES OF BALDUS, GARNIER, ETC. — 
THE AI.BERTYPE — OBERNETTER'S PROCESS— MODERN HELIOGRAPHY. 

From the origin of photography, even in Daguerre's time, 
it had been a matter of regret that the beautiful picture 
produced by Hght at the focus of the camera was con- 
demned to remain as an unique type ; it was asked if 
the art would not eventually be able to produce from the 
'negative an engraved plate capable of t)eing used for 
printing on paper in the ordinary way. At the present 

' Foi a description of the modem Hdiotype Process^ which is success- 
fully worked by the Heliotype Company of London, see Appendix. 

N 2 



l8o THE APPLICATIONS OF PHOTOGRAPHY. 

day these hopes have been in part realised ; if it has not 
yet arrived at the degree of perfection which will most 
probably be characteristic of heliography in a near 
future, it has yet been found possible to change the 
negative into a metallic plate similar to that used by 
the engraver on steel or wood. 

It was the noted savant M. Donne who first enter- 
tained the idea of acting on a daguerreotype plate with 
hydrochloric acid, so as to 'bite' the negative in the 
light parts, and to leave the shadow and half-tones 
in different degrees of relief, and thus to produce a 
plate capable of giving prints on paper in the com- 
mon printing-press. But the mercury employed 
in the daguerreotype process is not always equally 
distributed over the silvered copper-plate, and it is 
often only of an extraordinary thinness, so that the 
parts etched by the acid are so extremely shallow as 
to give but very insufficient relief to the rest ; besides 
which, the parts left in relief being formed of silver, a 
very soft metal, allows but a limited number of im- 
pressions being taken. The early heliotype plates were 
worn out and useless before fifty prints on paper, and 
these still very imperfect, had been taken from them. 

Fizeau improved this rudimentary process, but he so 
complicated the operations as to make his method prac- 



HELIOGRAPH Y. l8l 



tically useless. He succeeded in attacking the shadows 
and darker parts of the daguerreotype plate, whilst 
leaving the whites formed by the mercury in relief But 
the chief essential in a good engraving is depth in its 
reliefs ; the grooves and cavities opened by the acid must 
be deepened. Fizeau effected this in the following way : 
he filled the grooves and hollows with a greasy oil, which 
did not adhere to the parts of the plate in relief The 
latter he gilded with a battery, and then removed the 
oil contained in the groov^es, and by aid of nitric acid 
the latter could now be made as deep as desired, the 
salient parts of the plate being protected by their 
covering of gold. 

After these ingenious labours of Fizeau, photography 
on paper was discovered, and heliography seemed likely 
to lose its interest. It was not long, however, before this 
problem of photographic engraving was recognised as 
worthy in all respects of fixing the attention of enquirers. 
It is true that by the process of photographic printing 
on paper one has at once a negative on glass which will 
produce any quantity of proofs ; but how slow is the 
printing ! what numerous obstacles there are in the way 
of this process, which requires sunlight and careful 
attention to minute detail unknown in the production of 
printing-press proofs ! and besides, photography on paper 



1 82 THE APPLICATIONS OF PHOTOGRAPHY. 

is not durable ; it fades with time, sometimes turns 
yellow, and often even becomes completely effaced. 

Photographic engraving was again studied with ac- 
tivity. Talbot and Niepce de Saint Victor succeeded 
in engraving transparent objects on steel by the aid of 
photography. They employed bichromate of potassium 
as their sensitising agent ; but their results were coarse 
and devoid of all artistic value. 

In 1853 M. Niepce de Saint Victor published a 
method of transferring a photographic negative on to 
steel, based on the first process of his relative, Nicephore 
Niepce. 

His method was as follows : — A steel plate well 
cleaned and polished is covered with a coating of bitumen 
of Judea, which is spread on the metal by being previously 
dissolved in essence of lavender.^ , This coating is dried 
in the dark room, so as not to be affected by light. That 
done, a glass positive is applied to the metal plate thus 
sensitised, and the whole is exposed to the light, which 
acts on the bitumen through the transparent parts of the 
positive. The exposure must be continued for about 
fifteen minutes. The glass plate is then taken off the 

' According to Mr. Monckhoven, the bitumen of Judea or asphaltum 
best for these operations should be completely insoluble m water ; it should 
dissolve in the proportion of 5 to the 100 in alcohol, of 70 to the 100 in ether, 
and entirely in essence of turpentine, in pure benzine, and in chloroform. 



HELIOGRAPHY. 1 83 



steel, and the latter with its coating of bitumen is 
washed in a mixture of benzine and naphtha oil, which 
dissolves only those parts of the coating which were pro- 
tected from the action of the light by the opaque parts 
of the photographic positive. 

The parts of the steel plate laid bare by the solvent 
can be bitten in with nitric acid, and the rest being thus 
left in relief, the plate may be used for printing with ink 
on paper, and produces an exact copy of the photograph. 
These engravings of Niepce de Saint Victor were not 
without a certain merit, but, on the other hand, they pos- 
sessed grave defects ; the shadows, particularly, present no 
gradation or detail, being mere uniform blots which con- 
verted the engraving into little more than a coarse out- 
line. It was in vain that M. de Saint Victor endeavoured 
to improve his process ; he shortened the exposure and 
took impressions direct on to the steel plate by means of 
the camera, but all to no purpose, and after years of 
persevering research he was unable entirely to overcome 
the difficulties in his way. 

Whilst M. Niepce de Saint Victor was thus attempt- 
ing the solution of his difficult problem, M. Poitevin, an 
engineer of note, of whom we have already spoken, 
opened up new and unexpected horizons in the domain of 
photographic engraving. Since 1839, Poitevin, struck 



1 84 THE APPLICATIONS OF PHOTOGRAPHY. 

with the report read by Arago on the fixation of the image 
of the camera, had been an ardent disciple of Daguerre ; 
but his work as an engineer prevented him from imme- 
diately occupying himself with the study of the interest- 
ing problems which he hoped ultimately to solve. * In 
1842,' says Poitevin, 'whilst experimenting with elec- 
trotypy for reproducing the images formed on the silver 
plates, I had observed that the daguerreotype plate, on 
being taken from the mercury fuming box, and bearing 
on its surface the representation or image of which the 
whites were formed by the amalgam of silver, and the 
blacks by the iodide of silver unaltered by the light, re- 
ceived a deposit of copper on the white parts only, with- 
out the blacks or shadows being affected, when plunged 
in the electrotyping bath ; of this, which was my first 
discovery, I made repeated trials, all of which succeeded ; 
but, forced to suspend these distractions (for at that 
period they were nothing more to me), and devote my- 
self to my career of engineer, it was not until 1847 that 
I was enabled to take them up again as serious studies. 
I applied my observations on engraving with acids to the 
transferring on metal of the ioduretted designs of M. 
Niepce de Saint Victor, then to daguerreotype images on 
double silvered plates, and soon after to the transforma- 
tion of daguerreotypes into negatives capable of being 



HELIOGRAPHY. 1 85 



used for printing in the ordinary way on papers sensi- 
tised with nitrate of silver. 

During twenty years Poitevin laid the first founda- 
tions of several distinct methods, all of which have their 
originalities and applications. These processes were for 
a long time very little known, but, happily for science, 
the inventor at the end of his career decided to pub- 
lish all the methods which he employed in a brochure, 
which is now very rare, entitled ' Treatise on Photo- 
graphic Impression Without Nitrate of Silver.' * This 
brochure,' as one of his biographers truly says, ' is not a 
manual, nor a treatise, nor a book ; it is more than all 
this : it is the resume of the persevering studies of a man 
who, knowing many things, for twenty years applied all 
his knowledge to the realisation of a single object — the 
progress of an art which he loved passionately, and of 
which from the commencement he understood the true 
destiny.' 

The first method worked out by the clever operator, 
which may be called the galvanoplastic or electrotype 
method, is as follows. 

A photograph is taken by the daguerreotype process. 
When the picture has been developed with the mercury 
fumes, without removing the unaltered iodide of silver, 
the plate is attached to the negative pole of an electric 



1 86 THE APPLICATIONS OF PHOTOGRAPHY. 

battery, and plunged in the electrotype bath. The de- 
posit of copper takes place only on those parts of the 
plate which are not protected by the non-conducting 
coating of iodide of silver. 

This operation finished, the plate is next washed in a 
solution of hyposulphite of soda, which removes the 
iodide of silver, and lays bare the metallic silver beneath. 
In the electro thus obtained the lights of the picture 
are covered with copper, the shades are formed by the 
silver of the plate. The plate is then gently heated to 
oxidise the copper, and quicksilver is spread over it. 
The liquid metal amalgamates only with the silver, leav- 
ing the oxide of copper bare. Next the plate is covered 
with gold leaf, and the same phenomenon is reproduced ; 
the gold adheres only to the amalgamated parts, which, it 
must be remembered, represent the shades of the picture. 
The lights still remain indicated by the oxide of copper. 
This partial gilding of the plate being accomplished, it 
only remains to subject the plate to nitric acid or aquafor- 
tis ; the acid attacks the plate wherever it is unprotected 
by the gold coating. By this means the shades of the 
picture, represented by the gold-coated parts, are left in 
relief, and thus a plate is produced capable of being used 
for typographic printing. 

After the first attempts Poitevin directed his ex- 



HELIOGRAPH Y. 1 8/ 



periments in quite a new direction ; he transferred the 
photographic proofs not now to metal but to stone, and 
his ingenious method was invented under the name of 
photo-lithography. 

Photo-lithography. — On a stone of good grain 
and quahty, Poitevin spread a mixture of albumen and 
bichromate of potassium. He placed on this surface a 
photographic glass negative, and then exposed the whole 
to the light. The light, as we have already explained, 
only acts through the transparent parts of the negative. 
By this means, that is, by the mysterious influence ex- 
erted by the light on the gelatinous or gummy bichromate 
coating, the stone is made capable of retaining printing 
ink. As soon as the glass negative is removed, the 
surface is moistened with water, an inking roller is 
passed over the stone, and the ink only adheres to those 
parts of the coating on its surface which have been 
acted upon by the light. The original photograph thus 
becomes a lithographic stone. ^ 

' See Poitevin's work, ' Photographic Impression Without Nitrate of 
Silver.' Paris 1862, 

\Ve will complete this summary description with the following passage, 
extracted from the report of the photographic commission charged to exa- 
mine the photo-lithographic process : — 

' If an ordinary lithographic stone is covered with an albuminous solu- 
tion mixed with bichromate of potash, and if this liquid is allowed to dry 
spontaneously, the albumen, however much it may be altered in its nature, 
is not in its solubility, and a simple washing in ^^•arm water is sufficient to 



1 88 THE APPLICATIONS OF PHOTOGRAPHY. 



The discovery of this singular fact, which established 
photo-lithography, is certainly one of the most remark- 
able made by Poitevin, but this clever experimentalist 
did not rest content at this point. He soon discovered 
that his gelatinous bichromate of potash coating loses its 
properties of swelling when it has been submitted to the 
action of light. The impressioned film, treated with water, 
under special conditions swells slightly in the parts which 
the light has not acted on ; while it remains unaltered in 
those parts where the light has acted. Here then was a 

remove from the stone the greater part of the unaltered matter which has 
been unable to penetrate it. But if the surface thus prepared is exposed to 
the action of light through the unequally transparent parts of a negative, 
a change takes place which is certainly not an ordinary coagulation, and to 
which the oxidation of the chromic acid doubtless contributes, by rendering 
the albumen insoluble, and causing it to remain on the stone in quantities the 
larger the more intense the exposure to the light has been. Thus changed, 
the albumen resists water as if it were a greasy or fatty substance. In this 
state it readily absorbs an ordinary greasy ink, which does not adhere to 
the portions of the stone where the light has not acted, so that, if a roller 
charged witji an ink containing soap, which lithographers call transfer or re- 
printing ink, is parsed over the stone the ink adheres only to the albumenised 
parts of the surface, and the latter is thus coated with a greasy ink distri- 
buted in varying proportions of an ordinary drawing. The excess of ink is 
removed by acidulation and damping with a sponge. The drawing is made 
level by being submitted to the ordinary lithographic operations, that is to 
say, the removing of the colour with essence of volatile oil and the re-inking 
with the roller ; and nothing further remains but to cover the stone thus 
prepared with a coating of gum which only adheres where there is no ink, and 
to submit it to ordinary inking and to acidulation, to be enabled to obtain 
from it as many copies as if the drawing, which has been entirely made by 
the light, had been made in the ordinary lithographic manner. Such is 
M. Poitevin's method.' 



HELIOGRAPHY. 1 89 



substance which offered an unequal surface, the reHefs 
and depressions of which corresponded to the h'ghts and 
shades of the photograph ; there was therefore nothing 
to hinder an electrotype being cast in copper from it, and 
the result would be an engraved plate capable of being 
printed from in the usual way. It is hardly necessary 
to say that we give here only the principle of Poite- 
vin's process, which, in practice, requires extreme care. 
This principle was essentially ingenious, and capable 
of giving results which, if not perfect, were at least 
satisfactory. Poitevin must be regarded as the founder 
of modern heliography, his work being the germ 
of almost all the mechanical printing processes now 
known. 

Photo-lithography has long been used with advan- 
tage ; we shall see that it was the basis of photoglypty, 
the actual results of which are so remarkable. It gained 
for its inventor the celebrated grand prize founded by M. 
le Due de Luynes. 

Since 1857, M. Lemercier, an artist and savaiit oi 
great merit, has utilised M. Poitevin's processes with ex- 
cellent results ; and Poitevin himself has also produced 
some beautiful collections, among which we may men- 
tion an album of forty-five terracottas, photographed in 
the galleries of the Viscount de Janze, a photographic 



1 90 THE APPLICATIONS OF PHOTOGRAPHY., 

reproduction of the engraved stones of the Egyptian 
museum of the Louvre ; and in the galleries containing 
the most remarkable products of our national industry 
in the Museum of Art and Industry, may be seen a 
beautiful photo-lithographic stone. 

The Processes of Baldiis, Gamier and Salmon. 
In measure as we get nearer to our own time we find 
progress became more rapid. In 1854 M. Baldus pro- 
duced proofs of photographic engraving which justly ex- 
cited public admiration. M. Louis Figuier thus de- 
scribes this process : — 

' A coating of bitumen of Judea is spread on a cop- 
per plate. On the plate thus prepared with the impres- 
sionable resin is placed a photographic proof of the 
object to be engraved on transparent paper. This proof 
is a positive, and must in consequence produce, by the 
action of the light, a negative on the metal. About a 
quarter of an hour's exposure suffices to imprint the ob- 
ject on the resin, though it is not visible. It is developed 
by washing the plate with a solvent which clears away 
the parts unaffected by the light, and leaves a negative 
picture formed by the parts of the bitumen rendered 
soluble by the solar rays. 

' But this picture is formed of a film so delicate and fine 
that it soon begins to partly disappear from the effects of 



HELIOGRAPH Y. 191 



immersion in the liquid. To give it the necessary soli- 
dity and resisting power, it is left for two days to the 
action of diffused light. After the picture has been thus 
consolidated, the metal plate is plunged into an electro- 
typing bath of sulphate of copper, and now comes the 
most wonderful part of this process. Attach the plate 
to the negative pole of the battery, and on all the parts 
of the metal unprotected by the bitumen a coating 
of copper in relief will be deposited ; attach it to the 
positive pole, and the parts which are unprotected will be 
attacked and hollowed, or, technically speaking, bitten out. 
Thus can one obtain at will from the negative pole an 
engraved plate, which can be used for printing from like 
a wood engraving, and from the positive pole a plate as 
used in copper-plate printing.' ^ 

Since this time, M. Baldus has quite dispensed with 
electrotypy. A few minutes suffice him to make the 
plates fit for the copper-plate engraving process. 

It is by means of a chromic salt without using 
the bitumen of Judea, that M. Baldus sensitises the 
copper plate. On a plate thus sensitised is placed the 
glass negative or positive which is to be reproduced, 
and the whole is exposed to the action of the light. 

' It will be seen that this process is very similar to the electrotypin'g 
method of Poitevin. 



192 THE APPLICATIONS OF PHOTOGRAPHY. 

After exposure the plate is placed in a solution of per- 
chloride of iron, which attacks it in all the parts 
where the salt has not been acted upon by the light ; a 
first relief is thus obtained. 

As this first relief is not sufficient, it is augmented by 
replacing the plate in the perchloride of iron solution, 
after having passed over it a printing-ink roller. The 
ink attaches itself to the parts of the plate in relief, and 
protects them from the action of the mordant. By re- 
peating this treatment the lines of the picture may be 
deepened to the required extent. 

If a photographic negative is employed, a plate is 
produced for use as in the copper-plate process ; if a 
positive, then the lines formed are in relief, and the plate 
can be used for typographic printing. 

A little later on, in 1855, a new and extremely in- 
genious process was brought out by MM. Garnier and 
Salmon, of which the following is a description : — 

' A brass plate is exposed, in the dark, to vapours of 
iodine, then submitted to the action of light behind a 
negative, and rubbed with a cotton polisher soaked in 
mercury, which only attacks the parts unaltered by the 
light. An inking roller being now passed over this plate 
the ink is repelled by the parts where the mercury has 
acted, and adheres in the free parts. The latter there- 



HELIOGRAPH Y. 1 93 



fore, form the shadows, and when treated with nitrate 
of silver give a plate capable of use as in copper- 
plate printing. But if the ink is not removed, and, 
after the first corrosion with the nitrate of silver, a 
coat of galvanised iron deposited on the plate, the 
iron adheres only to the parts where the mercury- 
acted, and the ink being now removed leaves bare 
the iodised brass. Mercury is again applied to the 
plate, and does not adhere to the iron. Passed under 
the inking roller the ink only adheres to the iron. If a 
typographic plate is required, instead of iron, gold is 
used to form the deposit, and the parts unprotected by 
the latter are bitten with an acid to the required depth.' ^ 

By an analogous process M. Garnier obtained helio- 
graphic engravings made from negatives of views of 
monuments, landscapes, &c., of very remarkable quality. 
This operator received the grand prize for photography 
at the Exhibition. 

In the last few years the processes which we have 
been describing have undergone many most important 
improvements. We shall glance at the methods as 
actually used by some celebrated operators. 

Albertype. — M. Albert is a photographer of Munich. 

• Traite general de Photographic, par Monckhoven, sixi^me edition. 
G. Masson. 1875. 

O 



194 THE APPLICATIONS OF PHOTOGRAPHY. 

well known from his remarkable works ; his name has 
with justice been given to some photo-lithographic pro- 
cesses based on Poitevin's method. Heliographic en- 
gravings for the production of portrait-cartes are daily- 
made in M. Albert's studios at Munich, and 200 engrav- 
ings can be easily furnished from a plate in 12 hours. 

A thick glass well polished is covered on its polished 
side when placed in a horizontal position with a solution 
of gelatine and bichromate of ammonium and albumen 
previously heated. This first slight coating is exposed 
to the light to render it insoluble in water. "When this 
operation, which requires great delicacy and care, is 
finished, the first coating of gelatine is covered with 
another of gelatine isinglass, bichromate of potash, and a 
mixture of resinous matters (benzoin, tolu) in alcohol. 
When dry, the plate thus prepared is placed in a print- 
ing frame under the negative to be reproduced. When 
the exposure has been sufficiently long, the plate is 
plunged into tepid water, which dissolves the soluble parts 
unaltered by the light, and leaves slightly in relief the 
parts where the light has acted. This operation finished, 
the plate, when dried and rubbed with an oiled flannel, is 
ready for inking, which is done with an inking roller in 
the lithographic press ; and * this,' says M. Monckhoven, 
who has seen the clever experimentalist at work, ' is the 



HFXIOGRAPHY. 1 95 



most delicate and difficult part of the process, and re- 
quires a clever workman to do it well. If the ink is 
sticky or pasty it is removed with turpentine and a sponge. 
The plate must be placed with care on to a sheet of 
india-rubber or a coating of plaster, with papers super- 
posed, &c. The greasy ink with which the rollers are 
coated should be of superior quality. Purple is often 
added to it to give the proof the same appearance as 
photographic proof, and those obtained by M. Albert, in 
point of exactitude, delicacy, and tone, leave nothing to 
be desired.' 

Obernetter's Process. — In this process, which gives 
very good results, and is very successful in Germany, the 
gelatine coating, exposed behind a negative, is covered 
with an impalpable, metallic, zinc powder. The plate, 
after this operation, is heated to a temperature of 200° 
centigrade. It is submitted to the action of a very 
weak solution of hydrochloric acid, and then well washed 
The parts of the gelatine covered with the metallic 
powder can be more or less damped and therefore refuse 
the greasy ink, whilst those free from the zinc receive it. 

Modern Heliography. — There is a considerable num- 
ber of methods of photo-engraving. At Paris some 
operators have arrived at very satisfactory results, but 
the greater part of them have processes based on secret 

o 2 



ig6 THE APPLICATIONS OF PHOTOGRAPHY. 



operations, and minutiae, analogous to Poitevin's methods. 
To show what may be done by these processes the reader 
is referred to the opposite engraving which has been 
printed With the text, and is a reproduction of a sketch 
by Gustave Dore, photographed and engraved by pro- 
cesses similar to those which are here described in this 
chapter. 

We take it for granted the reader can distinguish the 
copper-plate engraving, which is formed by grooves in 
the metal, from the typographic plate, in which the lines 
forming the picture, instead of being sunk in, stand out 
in relief from the metal. Heliography thus furnishes, 
first, plates in which the lines forming the picture are 
hollow and must therefore be printed as by the copper- 
plate process, and cannot be used for printing with 
type ; and secondly, the plate in relief, similar to a wood- 
cut, and very easily printed with type, as that has been 
done for our fig. 38. This last process of heliography 
is especially useful for illustrating scientific and other 
books. Photoglypty (Woodbury process), which we 
shall describe in the next chapter, admirable though it 
is, as yet only produces plates, which must be printed 
without text in a special press. 

Amongst the most noted French operators we may 
mention M. Rousselon and Messrs. Dujardin Brothers. 




Fig. 36 



SPF.CIMEN OF A HELIOGRAPHIC ENGRAVING. 

(After a Drawing by Gustave Dore. ) 




Ce n'etait qu'un soldat obscur entre dix mille. 

guand on eut la victoire, il voulut, le premier, 
n porter la nouvelle a sa lointaine ville. 
Et partit, fier coureur, agitant un laurier. 

Epuise par sa course effrayaate et sans treve, 
II mourut, des qu'il fut au terme du chemin. 
Heureux qui pent de meme, ayant atteint son revt 
Mourir, la flamme au coeur et la palme a la main. 

A. R. 



A PAQUieifon. 



CQKTOTs. 

Fig. 37 

the soldier of mauathon. 



[Page 197 



HELIOGRAPHY. 



197 



The former gentleman manages Messrs. Goupil and Co.'s 
heliographic establishment, and has succeeded not only 
in copying old engravings, but in reproducing Nature. 
Landscapes, monuments, and even portraits are now 
made by heliographic processes. Messrs. Dujardin apply 

Fig. 38. 




THE SOLDIER OF MARATHON. 

(Heliographic reduction of the opposite wood-engraving. 



themselves principally to scientific, engineering, geogra- 
phical, and cartographical reproductions, and the repro- 
duction of old manuscripts. They produce by heliography 
steel plates, which have great merit, both from the num- 
ber of copies they will furnish and the cheapness of 



I93 THE APPLICATIONS OF PHOTOGRAPHY. 



their production. These heliographic processes have 
already found numerous applications, nor will they be 
wanting in the future. They are used by VEcole des 
C//artes for the reproduction of manuscripts,^ by engineers 
and architects for reducing or enlarging their designs, 
by the Bank of Belgium and the Bank of France for the 
manufacture of notes. 

To give an idea of the utility of the new methods for 
reducing or enlarging, we have reproduced on the preced- 
ing page an engraving on wood representing the Soldier 
of Marathon, and facing it is a reduction of it which 
has been made by heliography. (See figs. 37 and ^8.) 

' The photographic reproduction of manuscripts becomes daily of more 
importance ; by its aid, texts which have become almost effaced, and which 
it is impossible for the eye to read, are made again legible. 



199 



CHAPTER II. 

PHOTOGLYPTY. (THE WOODBURY PROCESS.) 

WOODBURY— IMPRESSION OF A GELATINISED PLATE INTO A BLOCK OF 
METAL — WORKING OF PHOTOGLYPTIC METHODS IN PARIS — DE- 
SCRIPTION OF MESSRS. GOUPIL'S ESTABLISHMENT— M. LEMERCIER. 

Thanks to the improvements of the English scientist 
Woodbury, the wonderful operations which we have just 
been describing have been greatly perfected. The im- 
portance of photoglypty, an art born but yesterday and 
hardly known to the public, has seemed so great to us 
that we have thought well to reserve it for a special 
description. 

What principally excites admiration in this new 
process is that the proofs obtained by it are almost 
exactly similar to those produced by ordinary photo- 
graphic processes ; they have the same colour, the same 
appearance, and the same fineness of quality. Another 
almost inestimable advantage which this process offers 
is that the proofs maybe multiplied indefinitely and very 
rapidly. 



^200 THE APPLICATIONS OF PHOTOGRAPHY. 

How is this prodigy performed ? This is what we 
shall try and teach the reader, presuming in advance 
that he has already seen these photoglyptic pic- 
tures at the printsellers' and booksellers', and perhaps 
bought some of them, thinking that he was getting 
ordinary photographs. We were for a long time under 
a like delusion. Now that we are undeceived we think 
it useful and interesting to undeceive others, by thus 
describing an invention which is assuredly destined to a 
great future. 

M. Goupil, the publisher, well known to the Parisian 
public, has acquired the right to work the Woodbury 
processes. He has organised a fine establishment at 
Asnieres under the intelligent direction of M. Rousselon, 
who willingly initiated us into the mysteries of the new 
operations. 

We shall describe faithfully what we have seen and 
admired. The first part of the method is based on the 
properties of bichromatised gelatine. A sheet of gelatine 
is prepared with a slight admixture of Indian ink, or 
other suitable colouring matter, and sensitised with an 
aqueous solution of bichromate of potash. This leaf of 
gelatine is placed in an ordinary printing frame, in con- 
tact with the negative exposed to light, and treated as in 
the printing and developing of an ordinary carbon proof. 



PHOTOGLYPTY. 20I 



The latent image is registered in the gelatine in degrees 
of solubility or insolubility, just as in the carbon print, 
the degrees corresponding with every detail of the 
picture. The leaf is carefully removed from the printing 
frame in a dark room, placed on a glass plate covered 
with india-rubber varnish, and the whole is then placed 
for twenty-four hours in a receptacle containing tepid 
water constantly renewed in order to dissolve those por- 
tions of the gelatine which were protected from the 
action of the light, and thus render the leaf very much 
thinner. On being removed from its glass support, dried, 
and held up to the light, a faithful copy of the negative 
picture is seen ; the lights are hollowed out and the 
shadows in relief. In one word, the photograph is repro- 
duced in relief. 

It will be seen that up to this point the process is 
very similar to Poitevin's, of which we have spoken in 
the previous chapter. But the miracle now commences. 
The gelatine leaf is next placed between a plate 
of perfectly level steel bound with iron, and a sheet 
of lead mixed with antimony. The gelatine film with 
its design in relief and engraving thus lies between 
two metal surfaces, the one of steel to serve as 
support, the other of lead much softer. In this position 
it is submitted to great hydraulic pressure, equal to 



202 



THE APPLICATIONS OF PHOTOGRAPHY. 



more than 700,000 lbs., and the leaf of gelatine, you will 
say, will be crushed to powder beneath such pressure. 

Not at all ; it acts like the die when striking out a 
coin or medal ; although friable it is hard and unyielding, 

Fig. 39- 




PHOTOGLYPTIC PRESS. 



harder than the lead into which it penetrates. In fact, 
on being taken from the press the lead is found to have 
received the exact impression of the gelatine leaf, and 
the astonished spectator sees every detail of the photo- 
graph reproduced in the metal, while the gelatine relief 
leaves the press quite uninjured and may be used again. 



PHOTOGLYPTY. 



203 



The lead plate is next placed in a special press (see 
fig. 39), and supplied with a semi-transparent ink formed 
of gelatine and Indian ink coloured with sepia ; a sheet 
of paper is placed over this, the lever is pressed down ; 



Fig. 40. 




TURN-TABLE REQUIRED FOR TAKING PHOTOGLYPTIC PROOFS. 



and on being raised a few moments after, to anyone who 
has not seen the details of this astonishing process, the 
paper seems to have been converted into an ordinary- 
photograph. The press once set going 10,000 facsimile 
prints can be obtained in a week. 



204 THE APPLICATIONS OF PHOTOGRAPHY. 

The photoglyptic presses are placed on a rotatory 
table in such a way that the workman can keep them 
constantly supplied with the thick jelly-like ink. (Fig. 
40.) The ink can be coloured to any shade, but sepia is 
the most generally used, as it gives the appearance of 
the photograph. 

It is possible to use glass instead of paper for printing 
on. Photoglyptic proofs on being taken from the press 
are washed in an alum bath, which makes the print 
insoluble and so fixes it ; they are then dried, trimmed, 
and mounted on cardboard, and are now ready for sale. 
It is hardly necessar}^ to say that in this description we 
have had to confine ourselves to giving our readers the 
principles of the photoglyptic process, without being able 
to enter into the detail of the delicate manipulations 
which require great skill on the part of the operator. It 
will be patent to everyone that the photographic nega- 
tive from which the photoglyptic proofs are to be formed 
must be made under the best conditions of sharpness 
and clearness ; the lights and shades should be distinctly 
defined, so that the gelatine film receives the action of 
the light freely. 

M. Goupil is not the only one who makes use of this 
processs. M. Lemercier has also organised a fine pho- 



PHOTOGLYPTV. 205 



toglyptic studio, and copies have been printed to the 
extent of 5,500 by this clever artist.^ 

Photoglyphy is completely successful in the repro- 
duction of portraits from nature, but it is especially 
suitable for reproducing pictures, engravings, &c., which 
are rendered with great delicacy. The new invention has 
already placed an innumerable quantity of prints in the 

' In order to understand the principle of this beautiful process, the 
reader must bear in mind that the gelatine relief when subjected to pressure 
is first laid upon a perfectly flat and true plate of hard steel, the leaden 
plate is then placed upon the relief, and the whole pressed between the 
parallel jaws of the hydraulic engine. The direct result of the pressure is 
that the soft leaden plate has taken the tnie level surface of the steel, and 
the only divergence from this perfectly level surface is caused by the gelatine 
relief, which has impressed into the lead a complete intaglio picture in 
which the deepest shadows recede farthest from the level, while the high 
lights rise to the true level of the plate. The success of the process depends 
entirely upon the true level of the steel plate employed in the press. It 
will therefore be readily understood that in pulling the impressions the 
second press must also be supplied with a perfectly level plate of glass or 
steel. The intaglio slightly greased is placed in position and charged with 
a warm solution of semi-transparent ink, the paper placed in contact with 
the ink ; the level cover of the press is then brought down and locked. 
The superfluous material thus pressed out, the gelatinous ink sets in an 
instant, and the resulting proof is a pictorial relief in permanent ink ; the 
high lights have been pressed out, leaving the white paper exposed, and 
the semi-transparent ink rises in beautiful gradations through the delicate 
shades and half-tones, attaining its highest relief, and therefore its greatest 
opacity, in the deep shadows. But when the proof is thoroughly dry, it 
presents a flat surface which none but an expert could distinguish from an 
ordinary silver print, worked by the Woodbury Co. of London. 

The Woodbury process, worked by the Woodbury Co. of London, is 
largely used for book illustration on account of the delicacy and beauty of 
its proofs. It has, however, one great defect in the eyes of publishers, and 
that is, that the proofs require to be cut and mounted. — Ed. 



206 THE APPLICATIONS OF PHOTOGRAPHY. 



market, amongst which we may mention a great number 
of reproductions of pictures ; some of the latter having 
been produced to the extent of 30,000 copies and more. 
Photography, years ago, would have been powerless to 
furnish so large a number. Thus these photographic 
processes will henceforth rank among the industries. A 
theatrical journal has recently made use of photography 
for reproducing each week the portraits of four most 
noted dramatic artists. The prints are pulled in the 
Lemercier presses and mounted on the journal itself on 
a space reserved for each.^ This curious art must un- 
doubtedly prove of most valuable assistance for illus- 
trating books of fine art, travel, &c., by furnishing proofs 
which offer all the advantages of photography without 
its drawbacks. 

It is hardly necessary to insist further on the impor- 
tance of the new invention ; it will be plain to everyone 
that it must be considered as the solution of a great 
problem destined to be an epoch in the history of in- 
vention. The only objection which can be raised to 
photoglypty is this : Are the gelatine prints permanent ? 
Will they be as little affected by time as typographic 
prints ? It is probable, for it is not easy to see how 
gelatine and Indian ink can alter ; nevertheless, time 
alone can solve the question with certainty. 

' There are several photo-illustrated periodicals in London. — Ed. 



PHOTOGLYPTY. 207 



Another but less important objection might perhaps 
be taken to the somewhat uncouth name of the new 
discovery ; but this name is very appropriate to the pro- 
cess, being derived from two Greek words — photos, Hght, 
and gluptem, to engrave — to the union of which one will 
soon get accustomed. 



208 THE APPLICATIONS OF PHOTOGRAPHY. 



CHAPTER III. 

PHOTOSCULPTURE. 

AN UNEXPECTED DISCOVERY — PHOTOGRAPHY APPLIED TO SCULPTURE — 
WILLfeME'S PROCESS IN 1861 — DESCRIPTION OF PHOTOSCULPTURE. 

We have just seen that photography has furnished the 
engraver with appliances as valuable as they were un- 
expected ; but the art created by Daguerre can do yet 
more. 

Not only does it engrave the copper plate as done 
by the hand of the artist, but it comes to the aid of 
the sculptor, and relieves him in his work. 

In the course of the year 1861, the Parisian press 
announced that a well-known inventor had discovered 
the means of reproducing statues by photography, not 
merely to represent them in picture, which would hav^e 
been nothing wonderful, but to make diminutive fac- 
similes of them. If an object, animate or inanimate, 
whether marble statue or living man or woman, were 
placed in the midst of M. Willeme's (such was the name 
of the ingenious inventor) studio, a few days after a 



PHOTOSCULPTURE. 209 



little statue of clay would be modelled. It would be 
done by photography, and the statuary image would be 
the exact representation of the living model. 

Such a result appeared incredible, and the public, 
accustomed to being hoaxed by the press, looked on it 
with great distrust. But facts must be believed ; and as 
soon as the mystery was explained, it was seen that there 
was nothing fantastic or incomprehensible in Willeme's 
process, and it was soon proved that work, perseverance, 
and ingenuity alone composed the miracle. 

The new discovery was at once christened with the 
name of photosculptiire. This curious art is designed, 
not to transform a photograph on paper into a sculptural 
relief, but by the aid of photographs to imitate in a 
certain way a statue or living person. 

To explain the processes of photosculpture, we quote 
a passage from the Aitnuaire Scientifique for 1861, in 
which Willeme's invention is described: *A model is 
placed in the centre of a circular platform the circum- 
ference of which can be included in the field of a single 
camera, by which several photographs of the objec 
from different points of view are to be obtained. To 
simplify matters, suppose these photographs be restricted 
to four — first, A of the face, the 2nd B of the back, the 

P 



210 THE APPLICATIONS OF PHOTOGRAPHY. 

3rd C of the right profile, and 4th D of the left profile 
— of the object ; these obtained, it is necessary to use 
them for reproducing the model in relief. To effect this 
the plaster or clay to be sculptured is placed on a level 
plate, the circumference of which is divided into as many 
equal parts as there are photographs to be taken, in this 
case, therefore, four. Two upright tablets are fastened 
vertically and at right angles to each other to the plate 
on which the plaster is placed. These tablets are made to 
slide to or from the plate, and are for the purpose of 
holding two of the photographs which must be those 
of views at right angles to each other, such as the 
front A, and the profile C. In order that the photo- 
graphs may be exactly even, both they and the tablets 
are marked with a double system of horizontal and 
vertical lines, which greatly facilitate the placing in true 
position. 

* The two points of a pantograph, an instrument for 
counter-drawing, are applied ; the one to the photograph 
A, of which it follows all the outline, the other to the 
soft or hard mass on which it traces a silhouette, an 
exact copy of the silhouette of the photograph. Another 
pantograph at right angles to the first acts in a similar 
manner in reproducing the silhouette of the profile C. 
In the same way, the second points of the two other 



PHOTOSCULPTURE. 211 



pantographs, the first points of which are guided in the 
same way over the photographs B and D, reproduce on 
the block the silhouettes of the back and of the profile 
D. Simply with four operations the mass to be sculp- 
tured would be but very imperfectly manipulated ; but 
nothing prevents that instead of four, eight, twelve, or 
twenty-four views should be taken .... in fact, the 
number suflficient for obtaining the requisite continuity 
of the exterior outlines so that there would be but an 
edge or two to correct by hand. In any case the number 
of the pictures must be one divisible by four ; twenty- 
four is a very convenient and sufficient number. 

'The photographs are numbered in order from one 
to twenty-four ; the turning plate holding the clay to be 
modelled is also divided into twenty-four equal parts. 
The photographs on which the two pantographs act 
simultaneously are those taken at an angle of 90 degrees 
from each other, viz., one and seven, two and eight, three 
and nine, up to twenty-four and six, and each time the 
tablets receive fresh photos, the plate is turned one 
division. 

' But this series of twenty-four operations will only 
give the exterior outlines, and the statue will be incom-> 
plete until such indentations as the nostrils, ears, &c. 



212 THE APPLICATIONS OF PHOTOGRAPHY. 

have been brought out. These M. Will^me obtains by 
following with the pantograph not only the profiles, but 
also the lines of light and shade which represent parts 
in depression and relief.' 

In 1861, M. Willeme constructed a photosculpture 
studio at the top of the Champs-Elysees. He has suc- 
ceeded in reproducing some statues, and, not content 
with this, boldly attempted to produce the statue of a 
living person just as his portrait is taken in a photo- 
graphic studio. 

For some time past Messrs. Giroux have exhibited 
some of these curious productions ; amongst others 
diminutive figures of the Duke de la Rochefoucauld and 
Madame Galiffet may be seen ; but exact as are the 
copies of these personages, from an art point of view, 
they present nothing more than common and mediocre 
statues. How can a gentleman in a double-breasted 
coat, or a lady fortified with crinolines, compete with the 
Apollo Belvidere, or the Venus de Medicis ? nudity is 
imperiously exacted by the art of Praxiteles. In 
spite of his attempts M. Willeme failed, but he has none 
the less created a new application of photography worthy 
in all respects to be noted and taken up by some bold 
spirit 

Though, from an art point of view, sculpture after 



PHOTOSCULPTURE. 213 

nature by photography seems impossible, there is reason 
to hope that the first attempts of M. Willeme will be 
one day perfected, and that his process may then be em- 
ployed in reproducing, with precision and exactitude, the 
works of old and modern masters. 



214 THE APPLICATIONS OF PHOTOGRAPHY. 



CHAPTER IV. 

PHOTOGRAPHIC ENAMELS. 

VITRIFICATION OF A PHOTOGRAPH— CAMARSAC'S PROCESS — ^JEWELLERY 
ENAMEL — METHOD OF MAKING — POITEVIN'S METHOD— PERMANENT 
GLAZE PHOTOGRAPHS. 

We have seen that the image of the camera can be fixed 
on paper, on metals, and on glass. ^ It can also be so burnt 
into porcelain by a certain process that once annealed it is 
as indelible as ceramic painting, and resists time and all 
other deteriorating agents. Many manufacturers have 
employed photography for decorating porcelain vases ; 
and some of these productions are really works of art 
and good taste. 

M. Lafon de Camarsac was the first who conceived 
the idea of employing photography in this curious and 
unexpected manner. It occurred to him that it might 
be possible to transfer to porcelain a positive image 

' Transferred direct to the surface of a block, it dispenses with the 
Avork of the artist on wood, affording the engraver an exact and delicate 
guide for his gi'aving tool. 



PHOTOGRAPHIC ENAMELS. 21 5 

formed of substances vitrifiable by fire, to submit this to 
a high temperature, and thus to obtain an enamel which 
reproduced the original photographic design. With this 
object in view the inventor set patiently to work, and 
in 1854 photographic enamels were invented. 

To transform the heliograph into an indelible painting, 
Camarsac made a sensitive coating capable of receiving 
the impression from a glass photograph without adhering 
to the latter. After exposure to light the picture is 
formed clear and distinct. The inventor now substituted 
ceramic colours for the parts which.^ should be destroyed 
by the action of heat. 

By means of a fine sieve the inventor deposited the 
metallic oxide colours delicately on the surface of the 
coating ; he spread these powders either with a brush or 
by imparting a rapid movement to the plate. In pro- 
portion as the powder is spread over the coating, the heat 
should be gradually increased. The enamel powders 
follow most delicately all the features of the drawing, 
which they partly penetrate, and the vigour and delicacy 
of which they faithfully render. After cooling, the proof 
must be dusted to remove any particles of colour which 
may adhere to the whites of the picture. 

The piece is now ready for the buniing-in process 
which is done in the same way as usual in ceramic-paste 



2l6 THE APPLICATIONS OF PHOTOGRAPHY. 

colouring, a more or less hot fire being employed 
according to the nature of the colours to be produced. 

The fire destroys the organic substances, and fixes 
the picture formed by the indestructible colours as soon 
as they are vitrified. 

' One of the remarkable properties of these pictures,' 
says Camarsac, * is the appearance of fine enamel which 
they present, and which no other painting could 
furnish with a like degree of delicacy. This cir- 
cumstance proves fully that the powder enamel has 
taken exactly the pl^ace of the organic matter, and it 
must be seen that this appearance is due to the remark- 
able delicacy of the photographic deposit, which is formed 
in degradations of thickness inappreciable to the eye 
.... There is no colour which cannot be applied to the 
heliographic surface ; gold and silver are as easily used 
as blue or purple.' ^ 

It will be seen that the inventor of photographic 
enamels describes his process with great reserve, wishing 
doubtless t<9 keep it secret. But we are now acquainted 
with Poitevin's method, the details of which we will 
briefly describe. 

To produce a portrait on enamel for mounting, as 
they are often done, in a brooch (fig. 41), a pin, &c., a 

* Lafon de Camarsac's Patents, 1874. 



PHOTOGRAPHIC ENAMELS. 



217 



Fig. 41. 



positive on glass is first made of the object to be repre- 
sented. 

This positive is applied to a glass coated with a 
sensitised surface formed of a mixture of gum and 
bichromate of potash. The light traverses the trans- 
parent parts of the positive, and acts on the bichromate 
of potash in a manner which, though invisible to the 
naked eye, modifies it in such a way as to give only to 
those parts the curious property of retaining the charcoal 
dust or powder. As soon 
as the exposure to the light 
is finished, the bichroma- 
tised plate is removed, and, 
though appearing totally 
unaltered to the eye, if a 
fine charcoal dust issprinkled 
over it by means of a sieve 
(fig. 42), the charcoal only ad- 
heres to the parts where the 
light has acted and nowhere 
else. Thus this fine charcoal 

shower brings to view, as if by enchantment, a portrait 
both delicate and faithful, in which the distinctions of 
light and shade are well preserved. 

The photographic proof is thus developed, a coating 




PHOTO-ENAMEL BROOCH. 



2l8 



THE APPLICATIONS OF PHOTOGRAPHY. 



of charcoal showing the design ; but this coating is not 
permanent. By means of a brush a coat of collodion 
{fiormal) is spread over it, which soon dries. 

The next operation is one requiring very great dex- 
terity of hand. The fine coating of collodion has to be 



Fig. 42. 




DUSTING SIEVE. 



separated by the aid of pointed instruments from the 
glass plate, and brings away with nt the charcoal proof. 
The film of collodion is then placed on the convex plate 
formed of white enamelled copper ; a fixing paste similar 
to that used by ceramic painters is spread over the enamel 
with a brush, and the fixing agent becomes incorporated 



PHOTOGRAPHIC ENAMELS. 219 



with the carbonised parts of the proof, of which it retains 
the image or design. 

When subjected to a red heat in an enameUing fur- 
nace the fixing paste adheres to the charcoal powder, 
vitrification takes place, and all the organic matters are 
destroyed ; and the vitrified carbon alone is fixed in an 
indelible manner. 

If a coloured proof is required, the design in black is 
traced over by an artist with colouring pastes used for 
decorating ceramics, not always, of course, without some 
slight damage to the beauty of outline and tone of the 
photograph. 

Messrs. Desroche, Henderson, Lochard, Gongenheim, 
Forest, Berthand,and others, are justly celebrated for their 
photographic enamels, which are much used in jewellery, 
and we have seen portraits made by this last artist which 
have the quality of ancient miniatures, with the lifelike 
resemblance which photography alone can assure. 

Similar processes have been used by some operators 
to obtain the vitreous or glazed photographs of which 
some remarkable specimens were exhibited at the Exhibi- 
tion of 1867. 



220 THE APPLICATIONS OF PHOTOGRAPHY. 



CHAPTER V. 

PHOTOMICROGRAPHY. 

THE TOY MICROSCOPES OF THE PARIS INTERNATIONAL EXHIBI- 
TIONS— 450 DEPUTIES IN THE SPACE OF A PIN'S HEAD— ARRANGE- 
MENTS OF PHOTOMICROGRAPHIC APPARATUS — THE NATURAL 
SCIENCES AND PHOTOMICROGRAPHY — RESOURCES BORROWED FROM 
THE HELIOGRAPH. 

The reader who may have visited the International 
Exhibitions in Paris in the years 1859 ^^^ ^^^7 cannot 
have forgotten the wonderful productions of microscopic 

photography which appeared 
^1 ''- there. At the Palace of In- 

dustry thousands of objects 
were sold, giving some idea 
of the minuteness to which pho- 

TOY MICROSCOPE OF THE EXHI- 

BiTioN OK X867. tographic prints could attain. 

There were small microscopes (fig. 43) containing 
photographs the surface of which did not exceed the size 
of the head of a pin, where were to be seen through a magni- 
fying glass the portraits of the 450 deputies of the Empire. 




PHOTOMICROGRAPHY. 221 

Photography succeeds in taking the impression of a 
diminished image, but it is also capable of rendering 
permanent the images magnified by the microscope. 
Before studying Lilliputian photographs we shall pass in 
review those which able operators now obtain from 
images enlarged by the microscope. We shall examine 
the results of the process called photomicrography. 

Photomicrography has rendered and still renders 
every day the greatest services to the Natural Sciences. 
Microscopic study is fatiguing, and the eye cannot observe 
for long an object through the magnifying glasses of this 
instrument without feeling wearied. Thanks to photo- 
micrography, the naturalist can have in his hands prints 
representing under a considerable enlargement the infu- 
soria, grains of pollen, and the most delicate organs of 
vegetables or animals. On this account this art, the 
birth of yesterday, must already be considered as a 
valuable assistant to scientific investigation. 

We shall chiefly examine microscopic photography in 
relation to its application to the natural sciences. We 
shall do so by the aid of a distinguished amateur, as 
skilful a photographer as he is a good microscopist, M. 
Jules Girard, who has kindly authorised us to make ex- 
tracts from his interesting works. 

The arrangement of a photomicrographic apparatus 



222 THE APPLICATIONS OF PHOTOGRAPHY. 

requires peculiar care. * However well arranged a camera 
may be/ says M. Girard, 'it is indispensable that it should 
satisfy numerous conditions in ordinary photography, 
which it is more rational to avoid in photomicrography 
by simplifying and reducing the number of its parts. 
In adapting a microscope to the end of a camera such 
as every photographer possesses, there is no need of any 
particular arrangement, because any one of these instru- 
ments, of whatever kind it may be, is suitable for the pro- 
duction of a picture. Let it be a bellows camera which 
will draw out to about a yard, and of such dimensions 
as will take in a glass plate of 8 x lO inches ; this size 
will be more than sufficient. The shape of the glass plates 
usually sold, which are longer than they are broad, is not 
very suitable to receive an image which, being circular, 
is always inscribed in a square, when the whole field of 
projection is made use of: the circle is also more charac- 
teristic of microscopic impressions.' 

In order not to change anything in the arrangement 
of the camera there must be a plate-holder or series of 
plate-holders, which fit one within the other, and also 
fitting the slide which is used in ordinary photography. 
The glass plates must also be specially cut in squares of 
two or three sizes. The sensitive surface is thus more 
cleanly and regularly covered, and there will be also 



PHOTOMICROGRAPHY. 223 

more economy in the use of the chemicals. With certain 
glass plates, such as those used for the stereoscope, it 
would be advantageous to employ a double slide giving 
two impressions at the same time. 

The front of the camera is usually made moveable, 
so that lenses of various sizes can be used. 

The ordinary lens-holder being removed from the 
front of the camera, there should be fixed over the aper- 
ture, in such a manner as to prevent any light being ad- 
mitted at the junction, a truncated cone of india-rubber, 
strong black cloth, or other perfectly opaque flexible 
material, the tube of the microscope being irtserted into 
the narrow end of the cone. 

It is absolutely necessary that the junction should 
be made by a simple contrivance in order to give flexi- 
bility to every movement. A mere opening in the 
flange allowing the tube of the microscope to be in- 
serted into the camera would make the combination too 
rigid, for the two instruments must be so united as to 
preserve to each a perfectly independent motion (fig. 
44), so that that of the one may not interfere with that 
of the other. The microscope is thus withdrawn from 
the inevitable shakes given to the camera ; in regulating 
the focus, or in withdrawing, even with all possible pre- 
caution, the dark slide containing the sensitised glass 



224 THE APPLICATIONS OF PHOTOGRAPHY. 

plate, the slightest shake would cause a disturbance of 
the position of the image.^ 

As an ordinary camera cannot generally be sufficiently 



Fig. 44 




MICROSCOPE FITTED TO THE CAMERA. 



drawn out, there may be fixed to the flange a metallic or 
wooden cone, to the other end of which is fastened the 
india-rubber or black cloth junction. 

^ This independent action of the camera and microscope containing 
the object-glass, confers a decided advantage in the hands of a skilled 
operator. But the amateur would probably be safer in using the microscope, 
cone, and camera rigidly united, as it is of great importance to obtain a direct 
light thrown from the mirror of the microscope through the axis of the 
instruments ; and, moreover, the stage of the microscope which carries 
the object to be photographed and the prepared plate ought to be perfectly 
parallel to each other. — Ed. 



PHOTOMICROGRAPHY. 225 

In place of the ordinary camera a simple oblong 
box provided with a slide may be used, but then the 
focal distance would be invariably the same. Though 
an ordinary microscope may be used, it will be found 
better to have the tube made as short as the mechanism 
will admit of, as a tube of the usual length would pre- 
vent the expansion of the pencil of light thrown upon the 
sensitive plate. The interior should be coated with a dull 
black, or still better with very fine black velvet, in order 
to avoid any reflections from a polished surface. 

The microscope should be attached to a heavy metal 
stand so as to make it as steady as possible. The height 
of the support should be such that the optical axis of 
the microscope is exactly in a line with the centre of the 
ground-glass back of the camera. The apparatus could 
then be put on an ordinary table very firmly placed ; but 
the height of ordinary tables is not adapted to the con- 
venience of the operator, and want of sufficient height is 
a cause of constraint and fatigue. The best manner, in 
our opinion, to place it in a position suitable to work at 
one's ease is to let it rest on a bench, of the breadth of 
the camera and about a yard and a half long, mounted 
on solid legs having an outward inclination to give it 
more firmness (fig. 45). In order to compensate for the 

Q 



226 THE APPLICATIONS OF PHOTOGRAPHY. 

inequalities which are often found in flooring, it would be 
well to furnish it with levelling screws. 

Near the bottom of the legs another board might be 
fixed, which would increase their firmness and also be 
very convenient for placing any small articles upon 
while working, should there be no other table at hand. 
The height would be regulated, so that when standing, 
the centre of the ground glass would be on a level with 

Fig. 45- 




ARRANGEMENT OF THE PHOTOMICROGRAPHIC APPARATUS ON A BENCH. 

the eyes. To stand upright is perhaps a little more 
fatiguing than to make the trials of focussing seated on 
the edge of a lower table, but, by standing, one gains 
considerably in ease and quickness of movement* In 

' The bench ought to be made iong enough to support the camera when 
fully expanded. — Ed. 



PHOTOMICROGRAPHY. 22/ 

case the camera, when expanded, should be much longer 
than the bench which supports it, it would be necessary 
to add metal brackets, or in some other way support the 
extreme end of the camera to prevent any rocking mo- 
tion when the movable back is inserted or taken out. 

As this apparatus does not admit of the focussing 
of the image so readily as in the ordinary photographic 
camera, a bench like the one described — which may be 
readily moved to suit the light— will prove of great service. 
By not having the camera too much expanded the awk- 
wardness of stretching the arm to reach the focussing 
screw, when the head is under the focussing cloth, is 
avoided. In case of need recourse might be had to an 
assistant who would turn the screw according to direc- 
tions given. Wishing to avoid this inconvenience, M. de 
Brebisson has made use of a mirror placed at the bottom 
of the camera. The operator then leans over the appa- 
ratus placed upon a table of suitable height, the head 
under the focussing cloth, and the hand free to hold the 
screw. A system of screws and connecting rods has also 
been devised ; but a position even a little inconvenient 
to which one soon gets accustomed is preferable to 
having recourse to pieces of mechanism which act at a 
distance, and for that reason are often defective. The sen- 
sitiveness of a micrographic screw does not suit such ar- 

Q2 



228 



THE APPLICATIONS OF PHOTOGRAPHY. 



rangements well, for, however correct their action may be, 
it can never equal the free and direct motion of the hand. 
The microscope may also be placed vertically, as re- 
presented by fig. 46. 




VERTICAL MICROSCOPE ADAPTED TO THE CAMERA FOR PHOTOMICROGRAVHY. 

V is the focussing screw. O represents the slide 
which carries the object to be magnified, placed above 
the object-glass A. But the arrangement we have pre- 
viously described is to be preferred. 



PHOTOMICROGRAPHY. 



229 



The photomicrographic apparatus being properly 
placed, it is necessary to give every possible attention to 
lighting the object effectually. This is of very great im- 
portance in such operations. Under certain conditions 
the light of the sun may be replaced by an artificial 
light produced by the combustion of magnesium or the 
electro-magnetic light, or oxy-hydrogen light as in fig. 47. 

Fig. 47- 






PHOTOMICROGRAPHIC APPARATUS FOR ARTIFICIAL LIGHT. 

We shall not enter into matters of practical detail 
analogous to those we have described in the Second Part 
of this work ; we shall confine ourselves to speaking of 
the results due to this branch of the photographic art. 
The tissues of plants, insects, the marvels of the invisible 
world, which fatigue the eye when examining them 
through the microscope, are fixed on the collodion with a 
precision unknown to the most scrupulous draughtsman. 



230 



THE APPLICATIONS OF PHOTOGRAPHY. 



Fig. 48 gives the portrait of a flea photographed after 
being enlarged by a miscroscopic object-glass. The en- 
graving has been done in such a manner as to reproduce 
faithfully the photograph, which was taken by the pro- 
cesses described in this chapter. 



Fig. 49. 



Fig. 50. 





FACSIMILE OF THE PHOTOGRArH OF SECTIONS 
OF THE STEM OF A CANE. 



SECTION OF THE WOOD OF A 



Fig. 49 is the reproduction of a photograph of thin 
sections of a cane. At a is seen the transverse section 
o( the stem, and at b the longitudinal section. Beside 
it we place the section of a piece of fir represented in the 
same manner (fig. 50). 

By uniting the processes of heliography and photo- 
micrography, the photograph obtained directly from the 



PHOTOMICROGRAPHY. 



231 



magnified object has been converted into a heliographic 
plate. 

Fig. 51 is printed from a heliographic plate which 



Fig- 51 




CROUP OF DIATOMS. 



was taken from a photograph of diatomaceae representing 
these infinitely small objects magnified 450 diameters. 
This engraving is the mathematically exact copy of the 



232 



THE APPLICATIONS OF PHOTOGRAPHY. 



image given by the microscope. These astonishing 
organisms, which are met with in incalculable numbers 
on the surface of sea-weeds or pebbles which have been 
exposed to the action of mineral water, and which in 

Fig. 52. 




SECTION OF THE FIN OF A WHALE. 

reality are smaller than the smallest prick given by the 
finest needle, are here figured by the heliograph just as 
Nature has created them. 

Photography has fixed their images magnified by the 
microscope on collodion ; it has then formed the en- 



PHOTOMICROGRAPHY. 233 

graved plate, and enabled us to insert it in this book. 
This plate was produced by heliography from a very fine 
photomicroscopic negative by M. Jules Girard. The 
other two designs (figs. 52 and 53) were produced in the 
same manner. 

Fig. 53- 









El'IDERMIS OF A CATKRPILLAR. 



The first (fig. 52) represents the section of the fin of a 
whale. 

And the second (fig. 53) the epidermis of a cater- 
pillar. 

We think these examples are sufficient to prove the 



234 THE APPLICATIONS OF PHOTOGRAPHY. 

immense resources which the Natural Sciences may find 
in the processes of photomicrography. But if the operator 
is now able to fix the image of an almost imperceptible 
object magnified by the microscope, he can also, as we 
shall see, perform the inverse operation ; that is to say, 
he can photograph the image of an object reduced to 
Lilliputian dimensions. The toy microscopes, which we 
have already mentioned, afforded a trifling specimen of 
this last application of an art which subsequently pro- 
duced the photographic despatches of the siege of Paris. 



235 



CHAPTER VI. 

MICROSCOPIC DESPATCHES DURING THE SIEGE OF 
PARIS. 

APPLICATION OF MICROSCOPIC PHOTOGRAPHY TO THE ART OF WAR — 
THREE MILLION PRINTED LETTERS OF THE ALPHABET ON THE TAIL 
OF A PIGEON — ENLARGEMENT OF THE DESPATCHES — THEIR CON- 
VEYANCE BY CARRIER-PIGEONS. 

During the war of 1870-71, when Paris was invested 
by the enemy, photography succeeded in reducing the 
size of the messages sent by carrier-pigeons, so as to 
render them almost invisible to the naked eye. No 
philosopher could have imagined this use of photography, 
called forth by the dire necessities of war. 

No one can have forgotten the service rendered by 
balloons during the siege of Paris, nor the wonderful part 
played by carrier-pigeons, which brought to the besieged 
city news from the outer world. But these birds, how- 
ever strong they might be, could only carry with them 
very light burdens through the air. A thin sheet of 
paper two or three inches square was all the load that 
could be entrusted to these winged messengers. But 



2^6 THE APPLICATIONS OF PHOTOGRAPHY. 

how write orders, send despatches, give precise instruc- 
tions in such a minute letter ? the most able caligrapher 
could hardly make it contain the letters in a single 
page of a printed volume. 

Microscopic photography came to the assistance of 

Fig- 54- 




CARRIER-PIGEON WITH PHOTOGRAPHIC DESPATCHES. 

the besieged ; it solved the difficulty as no other art could 
have done ; it reproduced on a film of collodion weighing 
less than a grain, more than three thousand despatches, 
that is to say, the amount of sixteen pages of folio 
printed matter. 

We shall recall briefly these memorials of micro- 
scopic photography utilised by the aid of carrier-pigeons. 



MICROSCOPIC DESPATCHES. 237 

At Tours, all public or private despatches were 
printed on a large sheet of paper, which could contain 
about 300,000 letters. M. Dagron, who left Paris in a 
balloon, reduced this big poster to a small negative 
scarcely one quarter the size of a playing card. 

These were at first printed on a thin sheet of paper. 



Fig. 55- 




QflLL CONTAINING MICROSCOPIC DESPATCHES FASTENED TO A TAlL- 
FEATHER OF CARRIER-PIGEON. 

but afterwards on a film of collodion, which, though 
weighing less than one grain, contained the matter of 
several newspapers. 

Several of these films representing a considerable 
number of despatches were rolled up and enclosed in a 
quill about the size of a tooth-pick. This light and 
novel letter-box was attached to the tail of the pigeon as 
represented in figs. 54 and 55. The bird-messenger only 
carried this light burden. Care was taken on his arrival 
and at his departure to put a stamp on his wing to prove 



238 THE APPLICATIONS OF PHOTOGRAPPIY. 

the date of the receipt, or despatch of the messages 
(fig. 56). 

A very considerable number of printed pages were 
reproduced by the processes of M. Dagron and his 
assistant, M. Fernique. Each page contained about 5,000 
letters, say about 300 despatches. Sixteen of these pages 

Fig, 56. 




STAMPS, SHOWING WHEN DESPATCHES WERE FORWARDED OR RECEIVED, PRINTED 
ON THE WING. * 

were contained on a film about two inches long and one 
inch broad, and weighing less than one grain. We have 
endeavoured to give the exact appearance of one of these 
despatches in our figure 57. The reduction was made to 
the eight-hundredth part of the size of the original. Each 
pigeon could carry twenty of these films in a quill, the 
whole not weighing more than fifteen grains. These de- 
spatches united could easily form a total of two to three 



MICROSCOPIC DESPATCHES. 



239 



Fig. 57- 



627- 



"6V2 






millions of letters — that is to say, the matter of ten 
such volumes as this. 

To produce these very minute specimens of photo- 
graphy, recourse was had to the process already utilised 
before the war in the construc- 
tion of the little photographic 
toy microscopes, and of which 
the following is a description.. 
The albumen process was used, 
which gives the greatest pos- 
sible delicacy to the negative 
image. This small image, 
further reduced by the aid of 
lenses, is reproduced in the focus 
cf a camera, and fixed on a 
plate of collodionised glass, on 
which several microscopic photo- 
graphs are received at the same 
time. This plate will be a positive ; the plate from 
which it was produced being a negative. It is then 
cut into small fragments each containing a picture. 
M. Dagron fixed his little microscopic photographs in 
1867 into various articles, such as the toy microscopes 
already spoken of, into rings, penholders, &c. 






FACSIMILK OF A MICROSCOPIC 
DESPATCH DURING THE SIEGE 
OF PARI*. 



One of the practical difficulties at this time was the 



240 THE APPLICATIONS OF PHOTOGRAPHY. 

magnifying the little glass plates sufficiently. M. Dagron 
succeeded in doing so by employing the Stanhope 
lens.^ 

It is a miniature microscope with considerable magni- 
fying powers. The image seen through it is magnified 
about three hundred times.^ 

' The lens used for toy micropliotographs resembles the Stanhope lens, 
but is not cut down in the centre to form a diaphragm. It consists simply of 
a cylinder of flint glass, or long plano-convex lens whose focus is its ovm. 
plain surface, to which the photograph is attached with Canada balsam. 

2 As the author has given a full description of one of the most inte- 
resting and important applications of microphotography, I venture to append 
a brief supplementary account of my personal experience in the production 
of minute photographs. 

It is now nearly seventeen years since — after a series of experiments 
which extended over twelve months — I found out a method by which the 
finest results could *be readily obtained. The instrument used was a long 
camera set up in an inclined position, in a dark room, with its upper end 
projecting through an aperture in the window so as to command a clear 
northern light. The negative to be copied was placed in a frame at the 
end of the camera. While the lower extremity of the camera supported 
the object-glass of a microscope fixed in a sliding tube supplied with a 
coarse and fine adjustment, a glass stage with spring clamp was also added 
for the support of the collodionised plate. Above the stage there was 
placed an ordinary microscope set so as to correspond with the optical axis 
of the instrument. 

The first great difficulty to be overcome was focussing. To use any 
ordinary semi-opaque focussing screen would have been labour thrown away, 
as the image to be formed was not larger than a pin's head ; I therefore 
adapted a microscopic glass slip, and first brought the specks of dust on 
the-inner side of the glass into the focus of the microscope ; it was then 
necessary to focus the image cast by the object-glass on the same dusty 
plane. This method, however, turned out to be useless. As I was 
very young and inexperienced at the time, I was completely puzzled 
until I discovered that the refraction of the glass slip prevented me 



MICROSCOPIC DESPATCHES. 24 1 

The production of microscopic prints requires great 
ability on the part of the operator, and great delicacy in 
the various manipulations. 

from finding the actual focus. The focussing slip was at length thrown 
aside, and I determined to focus the tiny image in air without a screen, 
but with the silken hair from a spiders web stretched across the field on 
the glass rim of the stage, and on the same plane as that to be occupied 
by the sensitive plate. It was then necessary to focus the microscope to the 
silken thread, and afterwards to bring the tiny image to the corresponding 
plane. This, I need hardly say, proved absolutely satisfactory, and, more- 
over, when the focus had been once determined, it remained unaltered 
for an indefinite length of time. The ultimate success of micro-photography 
(with collodion) depends, greatly, on the accuracy of focussing, as the 
1,000th part of an inch of variation in the position of the object-glass throws 
the instrument out of adjustment. One object in using a glass stage and 
glass supports was to do away with the alteration of focus caused by the 
expansion and contraction of brass or other metal. 

The mode of operating which I followed in taking the photograph 
was nearly identical with that of taking an ordinary wet collodion positive, 
with one or two modifications very simple in themselves, but at first 
extremely difficult to find out. By using an ordinary collodion and an iron 
developer, the resulting picture, when placed under the microscope, would be 
so coarse in texture as to appear nothing more than a patch of gravelly soil. 

The nitrate of silver bath was of the common strength, first rendered 
neutral, and then slightly acid with glacial acetic acid. The developer was a 
weak aqueous solution of pyrogallic acid with glacial acetic acid, but no 
alcohol. As to the collodion, 1 could use almost any of the commercial 
samples, provided they gave a tenacious parchment-like film. But one of 
the great secrets of success lay in the time which the sensitised plate was 
kept in the silver bath. The duration of dipping was suited to the collodion 
for certain chemical reasons, which I have not space in this note to discuss, 
nor can I do more than give this simple outline of the micro-photogiaphic 
instrument and its manipulation. 

There is another application of micro-photography of great value to 
the microscopist. It consists in the photographing of ' finders ' on a square 
space of one inch divided into squares of one hundredth of an inch. Each 
square contains two sets of numbers from the unit up to one hundred 
running in opposite directions across the surface. These ' finders ' are all 

R 



242 THE APPLICATIONS OF PHOTOGRAPHY. 

The focussing, which is easily effected with impressions 
of the ordinary size, requires the employment of a micro- 
scope when the image thrown on the surface of the 
ground glass is of such a very small size. 

The usual dark slide of the camera is replaced by a 
support which keeps in a horizontal position a plate of 
collodionised glass, and carries besides twenty little 
object-glasses intended to produce as many microscopic 
reductions of the negative. Afterwards, by the aid of a 
diamond this glass plate is cut into twenty pieces, each 
containing a picture. We shall confine ourselves to 
mentioning these difficulties without entering into full 
technical details. 

During the war the processes were different, especially 
in magnifying the photographs for the purpose of being 
read in the besieged capital. 

taken in a mathematically accurate uniform position on glass slips of perfectly 
uniform size. Each slip fits into its allotted position on the stage of all" 
well-formed microscopes, and puts it in the power of the microscopist 
to determine, so to speak, the longitude and latitude of a single diatom, 
or group of diatomacese, or any minute object that may come within the 
field of his instalment. But this is not all. Should the microscopist 
make a discovery, the finder enables him to verify it. Let us suppose that 
some new diatom occupies the field of his microscope. It is a minute 
object quite invisible to the naked eye, and most difficult to find among 
the countless groups of its fellows. But the student, in order to fix its posi- 
tion, removes the slip from the stage and replaces it by the finder, when he 
at on.ce reads its number. This number he registers, and thus places it in 
the power of any savant to whom the slip may be sent, to hit upon the 
position of the diatom at once, by using his finder, bringing the number 
into the field and replacing the finder by the microscopic slip, — Ed. 



MICROSCOPIC DESPATCHES. 243 



Thirty or forty copies of the microscopic despatches 
were usually printed and sent by as many pigeons. More 
than one hundred thousand of them were thus sent to 
Paris during the siege. 

As soon as the small tube was received at the telegraph 
office, MM. Cornu & Mercadier proceeded to open it with 
a knife. The photographic films were carefully placed in 
a small basin of water in which were put a few drops of am- 
monia. In this liquid the despatches unrolled themselves. 
They were then dried and placed between two plates of 
glass. It only then remained to lay them on the stage plate 
of a photo-electric microscope. The preceding engraving 
(fig. 58) represents one of these interesting meetings for 
the purpose of transcribing the microscopic despatches. 

The image on the film of collodion is there thrown 
upon a screen by means of a photo-electric apparatus, 
which is, in fact, a very powerful magic lantern. The 
almost invisible letters are sufficiently magnified to enable 
the copyists to reproduce them on paper. 

When the despatches were numerous the reading of 
them was a somewhat slow process, but as each film 
contained a great number of pages or little squares, 
they could be divided and read at the same time by 
the use of several microscopes. 

Messieurs Cornu and Mercadier carried the process of 
R 2 



244 THE APPLICATIONS OF PHOTOGRAPHY. 

reading the despatches by means of the microscope to 
great perfection. The film of collodion pressed between 
two glass plates was placed upon the stage of the micro- 
scope to which a mechanical arrangement gave both a 
horizontal and a vertical movement. Each part of the 
despatch passed slowly over the field of the microscope. 
The characters displayed themselves upon the screen 
sufficiently magnified to be read and copied. The 
arrangement and process of reading the despatches 
lasted about four hours ; it required besides several hours 
to copy them. Messieurs Cornu and Mercadier tried to 
photograph the characters directly as enlarged and 
thrown upon the screen, but did not succeed in doing so 
in their first attempts. 

It is certain that improvements in the process would 
have progressed rapidly had not the severe cold of the 
winter caused the arrival of the pigeons to become more 
and more rare during the siege. 

Though details concerning these birds lie beyond 
our subject, which is essentially photographic, we do not 
think we can omit making a few remarks about them ; 
for having described the letters, it is only right to say a 
few words about the postmen. 

The severity of the season is not the sole obstacle 
which prevents the duties of the messenger birds from 



MICROSCOPIC DESPATCHES. 



245 



being properly performed ; they are exposed to other 
dangers on their passages, birds of prey being their most 
formidable enemies. 

Doubtless among the many carrier-pigeons which never 
.return to their home, there are a certain number which 



Fig 59. 




CHINESE WHISTLES ATTACHED TO CARRIER-PIGEONS. 

have been the victims of those aerial pirates, the hawks. 
The Chinese,' who often show considerable ingenuity in 



^ When in Pekin I was for some time puzzled by the musical tones 
which came from a number of birds whirling in circles over the city. The 
mystic sounds were at length explained to me by a Chinaman who owned 
pigeons and who armed them with the bamboo pipes used to scare awny 
birds of prey. — Ed. 



246 THE APPLICATIONS OF PHOTOGRAPHY. 

the plans which they adopt, have invented a very in- 
genious system to protect the carrier-pigeons, which are 
much employed in the Celestial Empire, from the birds 
of prey. They attach to the root of the tail of the 
messenger birds a set of very light bamboo whistles, as 
represented by fig. 59. When the pigeon flies, the air 
rushes into these little tubes ; this produces vibrations, 
causing a sharp and continued sound. If the birds 
travel in companies, the sets of whistles with which they 
are provided produce a noisy concert. People who have 
lived for some time in China, and especially at Pekin, 
report that in the country they have often heard the 
whistling and booming produced by these little tubes 
of bamboo belonging to the carrier-pigeons, without at 
first being able to account for the unexpected sound 
which seemed to descend from the skies. 

It seems to us that this process deserves attention. 
Everything should be done to perfect the organisation of 
the aerial post, which at present occupies the attention 
of many. We hope that this organisation may soon be 
ready to work, and that the history of the pigeons of 
the siege may be an encouragement to future breeders of 
these interesting and useful birds. 

We should not forget that in the fatal hour when 
France was invaded by her enemies, photography com- 




KiG. 60 I I'a^'c 247 

DEPARTURE OF CARRIER PIGEONS FROM THE CHAMPS-ELVS^ES, PARIS. 



MICROSCOPIC DESPATCHES. 24/ 

pleting the wonderful services rendered by the pigeons, 
was of great advantage to thousands of the besieged, 
imprisoned during five months by the German armies. 

Let us hope that the teachings of the past will 
be fruitful in the future, and that if France is again 
engaged in one of these bloody conflicts, the carrier- 
pigeons will play their modest part and give new assis- 
tance. This time we would fain believe they will only be 
the messengers of victory and good news. 

Breeding and training pigeons is the necessary com- 
plement to microscopic photography, as employed in 
making up and forwarding despatches during time of 
war. 

At present these useful winged messengers are not 
neglected, and quite recently an attempt has been made 
to encourage the breeding of them by valuable prizes 
offered for competition. During the year 1873, the 
people of Paris have shown their approval of these en- 
couragements by attending the departures of the pigeons 
which take place before the Palace of Industry from 
time to time (fig. 60). Such experiments cannot be too 
much encouraged. Carrier-pigeons are the safest bearers 
of these microscopic despatches, which convey to the 
besieged detailed news and explicit orders. 

In certain cases very remarkable results were attained 



248 THE APPLICATIONS OF PHOTOGRAPHY. 

by means of the aerial post. Here is an example men- 
tioned by M. Dagron : — * When nothing interfered with 
the flight of the pigeons,' says this talented operator, * the 
rapidity of the photographic correspondence was truly 
marvellous. I can myself give an example. Wanting 
some chemicals, especially gun cotton, which I could not 
procure at Bordeaux, I ordered them by pigeon despatch 
from Messrs. Poulenc and Wittmann, of Paris, on January 
18, 1871, begging them to forward them by first balloon. 
On January 24th the articles were delivered to me 
in Bordeaux. The pigeon had only taken twelve hours 
to pass from Poitiers to Paris.' The electric telegraph 
and railway could not have done better. 

This admirable use of microscopic photography, 
bringing to the aerial post by balloons and pigeons the 
indispensable complement of light messages, is a fine 
example of the close correlation which unites the 
different branches of modern science, and which enables 
them at a given moment to co-operate towards the same 
result. 



249 



CHAPTER VII. 

ASTRONOMICAL PHOTOGRAPHY. 

CELESTIAL PHOTOGRAPHY — DIFFICULTIES OF ASTRONOMICAL PHOTO 
GRAPHIC OPERATIONS — MESSRS. WARREN DE LA RUE, RUTHERFURD, 
GRUBB, ETC.— THE LUNAR MOUNTAINS- THE SPOTS ON THE SUN, 
ETC. — IMPORTANCE OF PHOTOGRAPHIC DOCUMENTS FOR THE HISTORY 
OF THE HEAVENS. 

Photography furnishes inestimable resources to all 
the sciences. We have seen that it places under the eyes 
of the naturalist the enlarged images of the grains of the 
pollen of a flower, infusoria, and of forms of vegetable 
and animal life invisible to the naked eye. 

Meteorology, as we shall show in the sequel, makes 
use of it to register with mathematical precision, with a 
constancy which nothing interrupts, all the variations of 
the barometer, of the thermometer, and of the magnetic 
needle. Geology finds it a useful assistant in repro- 
ducing, with an exactness which nothing can approach, 
the inclinations of the various strata it would study. The 
engineer employs it like a mirror, in which he sees from 
day to day the state of the works he is employed in 
executing. 



250 THE APPLICATIONS OF PHOTOGRAPH^. 

The applications of photography to astronomy in the 
study of the heavens are not less valuable. They 
furnish a remarkable assistance to those who devote 
themselves to the task of sounding the depths of the 
firmament. 

Though it is true that these applications are new 
and recent, it may be remembered that they were 
foreseen by Arago from the time of Daguerre. In his 
notice of the Daguerreotype, the illustrious Perpetual 
Secretary of the Academy of Sciences reports with 
admiration that the inveiitor of the diorama, at his 
request, had obtained an image of the moon on the 
sensitive silver plate. 

To reproduce at the present day the images of the 
celestial orbs by photography, the operator may employ 
one of the powerful telescopes which are to be found in 
all the principal observatories of the civilised world. 

It is indispensable to make use of a reflecting tele- 
scope having a speculum formed of glass, silvered 
according to Foucault's process. This instrument is 
achromatic, that is, its optical coincides with its chemical 
focus. The focussing of it therefore presents no difficulty. 

The telescope thus constructed should be mounted 
equatorially, as astronomers say, i.e. supplied with a 
moving power which during the operation follows exactly 



ASTRONOMICAL PHOTOGRAPHY. 251 

the motion of the celestial body the image of which is 
being taken. This movement, also, must be in the 
plane of the celestial equator— the same as that in which 
the star or planet moves. 

When an astronomer wishes to obtain the photograph 
of celestial bodies by means of Foucault's reflecting 
telescope, he removes from the instrument the eye-piece 
generally used and replaces it by a double ring, in the 
central part of which is fixed the collodionised glass- 
plate intended to receive the luminous impression. In 
order to focus the instrument the collodionised glass is 
replaced by a piece of ground glass and moved back- 
ward and forward until the image is sharply defined. At 
this moment the movable screen is quickly withdrawn ; 
the sensitive surface is exposed ; it receives directly the 
luminous rays v/hich reproduce faithfully the image of 
the celestial body millions of miles distant from our 
humble planet. The negative is fixed by the ordinary 
means, and will print an unlimited number of positive 
impressions on photographic paper. 

Mr. Warrren de la Rue is one of the astronomers who 
first attained the most perfect results of photographic 
astronomy. He managed to take an impression of the 
constellation of the Pleiades of remarkable sharpness, but 
he did not succeed in getting an impression of any of the 



2 52 THE APPLICATIONS OF PHOTOGRAPHY. 

nebulae. These clouds of suns are scattered through 
the heavens at such distances from our humble spheroid 
that the human mind, staggered when it would regard 
them, feels itself almost powerless to comprehend these 
measures of immensity. 

When the sky is clear, when no cloud mars the 
purity of the vault of heaven, the photographic im- 
pressions of the planets give fairly satisfactory results ; 
but the image is never perfectly sharp and distinct. 
These orbs, endowed with a weak actinic power, only leave 
an uncertain trace on the negative ; the fixed stars, true 
luminous points placed in the heavens at enormous 
distances from the earth and from our observatories, 
leave upon the coUodionised glass the trace of an 
excessively thin line, and sometimes it is very irregular if 
the atmosphere of the earth is overcharged with vapour. 
After having fixed on a photographic plate the trace 
of these stars, it is necessary to assist the eye with a 
good microscope to discover it. Our eye is as power- 
less to perceive it without the help of an instrument as 
we are to appreciate the greatness or the real distance of 
these suns lost in the depth of the heavens. 

In spite of the difficulties which the photography of 
the planets offers, Mr. Warren de la Rue, thanks to 
persevering labours and ingenious combinations, has 



ASTRONOMICAL PHOTOGRAPHY. 253 



succeeded to a certain extent. This learned astronomer 
succeeded, by the aid of an equatorial mechanism ad- 
mirably regulated, in keeping the image of the moving 
star for several minutes in the centre of the field of 
view of the telescope which moved along with it, and his 
efforts were crowned with legitimate success. 

He was able to take the photograph of Jupiter with 
his parallel zones. Nor has it been beyond the powers of 
this talented operator to fix upon the collodion the 
rough surface of the planet Mars and the mysterious ring 
of Saturn. 

If the photography of planets offers serious difficulties, 
that of the moon, which alters its place in the heavens 
much more rapidly, presents obstacles still greater ; but 
great though they be, they have been surmounted by 
Secchi, De la Rue, Rutherfurd, Grubb, and some other 
distinguished astronomers, as skilled in the manage- 
ment of photographic apparatus as in their knowledge 
of the heavens. 

We place before the eyes of our readers the facsimile of 
the photograph of a very interesting region of our satellite. 
Our engraving has the merit of reproducing exactly the 
appearance of the impression obtained by the English 
astronomer (fig. 61). 

Some years ago Mr. Grubb succeeded in photograph- 



254 THE APPLICATIONS OF PHOTOGRAPHY. 

ing the moon as correctly as if she had been sitting for her 
portrait in his own studio. Only as the Dublin astrono- 
mer could not utter the usual caution — Don't move — it 
was necessary that the telescope at the focus of which 
the image w^as to be fixed should move at exactly the 

Fig. 6 1. 




LUNAR MOUNTAINS. AFTER A PHOTOGRAPH BY MR. WARREN DE LA Rl E. 

same rate as the sitter. Mechanically such a result is 
not easy to attain with rigorous correctness. 



ASTRONOMICAL PHOTOGRAPHY. 255 

The great telescope constructed by Mr. Grubb 
for the Government observatory at Melbourne is a 
marvel of mechanism. The speculum is about 46 
inches in diameter, with a focal length of 30 feet, 
and its weight, including all its mountings, is about two 
tons. The tube is surrounded by a trellis-work of 
flat iron, but it is chiefly composed of bars of steel firmly 
fixed to solid rings of iron, the whole weighing about 
ten tons. To render the movement as easy as 
possible, all the bearings are supported by an ap- 
paratus to prevent friction. This telescope is so easy 
to manage, notwithstanding its enormous dimensions, that 
two persons can turn it round either vertically or hori- 
zontally in forty-five seconds. 

This instrument, which takes in the whole hemisphere, 
is put in motion by an excellent clock. In the course of 
the year 1869 Mr. Grubb presented to the French Photo- 
graphic Society photographs of the moon taken by the 
aid of this huge telescope, in a camera mounted at the 
end of the trellis-work tube. The time of exposure 
varied from half a second to two seconds, the brilliantly- 
lighted part of the moon requiring a shorter exposure 
than the parts in the neighbourhood of the dark side. 

Up to this time, as we have said, Mr. de la Rue in 
England and Secchi in Rome had alone succeeded 



256 THE APrLICATIONS OF PHOTOGRAPHY. 

in producing photographs of the moon worthy of the 
attention of natural philosophers or of astronomers. 

The impressions obtained by these gigantic instru- 
ments r.f Mr. Grubb in the serene atmosphere of Australia 
have greatly surpassed the highest efforts of European 
art. 

It is impossible to avoid a certain emotion in con- 
templating the negative of a lunar photograph, in admiring 
the raised appearance of the mountains of our satellite, 
and tracing upon the collodion the dark obscurities 
formed by its valleys. It is quite certain that it is 
mathematically correct, for it is the light from its surface 
that has winged its flight to our globe to print the 
picture of the rugged peaks, the craters, the strange 
hollows which appear on the surface of the orb of night. 

Marvellous result of science, which takes the minute 
counterpart of the silvery and mysterious disc suspended 
so far from us in the dark azure of the firmament ! 

There has been rapid and important progress in this 
fertile field. Mr. Rutherfurd has lately obtained photo- 
graphs of the moon of the greatest merit. Some impres- 
sions were presented to the Academy of Sciences in 
November 1872, by M. Faye, who, in offering these 
remarkable specimens, gave some details of the highest 
interest, which we are happy to borrow from him : — 



ASTRONOMICAL PHOTOGRAPHY. 257 

* These impressions, striking marks of the progress 
which astronomical photography has made in the 
United States, have been obtained by means of a 
lens of 13 inches' aperture, specially achromatised. 
From the negative, which was about four inches in 
diameter, a positive was taken of the same size, and this 
was then magnified by a powerful solar microscope. The 
exposure of the original negatives varied from one 
quarter of a second at full moon to two seconds at the 
first and last quarters. 

* The photographic lens was m.oved during the time of 
exposure at the same rate as the apparent motion of the 
moon, by clockwork of great accuracy. 

'A glance at these magnificent impressions is sufficient 
to make the service they may render to lunar geology 
appreciated. 

' The luminous lines, like cracks forming parts ot 
a great circle, intersect one another at angles which 
it is possible to measure with a certain amount of exact- 
ness. By the aid of an outline map on which are marked 
the lines of latitude and longitude, calculated pre- 
viously so as to correspond with the particular phase of 
the moon, and drawn upon a sheet of transparent paper, 
and then applied to these beautiful maps, the geome- 
trical elements of these arcs in relation to the lunai^ 

S 



258 THE APPLICATIONS OF PHOTOGRAPHY. 

equator can be obtained. The circles, the craters, and 
even the smallest circular hollows which the surface 
of the moon exhibits in great numbers, are there 
represented on a large scale with a startling fidelity 
which no printed chart could equal. One can there study 
at leisure the numerous varieties of these different objects 
so similar at first sight to our extinct volcanoes, and yet 
so different in some respects from their terrestrial repre- 
sentatives. Photography shows the heights of these 
mountains by showing the length of their shadows as 
well as their horizontal dimensions. 

Among the lunar formations best represented by 
photography are what are called seas, the want of 
light or rather the dull colour of which strikingly con- 
trasts with the brightness of the mountainous parts. One 
is struck by their aspect quite as vividly as by the direct 
inspection of the moon, with the idea that there are before 
you vast discharges of fluid matter, which have covered up 
the previous inequalities of the surface, leaving here and 
there on its coasts some vestiges of primitive cycles. 

If photographs of the moon are fruitful in informa- 
tion, those of the sun are not less rich in their teachings ; 
and the spots which sully the purity of the orb of day 
have been imprinted on the glass plate of the camera. 

Celestial photography has recently been applied at 



ASTRONOMICAL PHOTOGRAPHY. 259 

Harvard College in the United States to the double stars, 
in order to determine by micrometric measurement their 
relative angle of position and distance. 

In the photographic reproduction of the stars recently 
undertaken by Mr. Rutherfurd, it has been found neces- 
sary to take special precautions with the sensitive plate, 
so as to distinguish these impressions from accidental 
markings on the film of collodion. To prevent any chance 
of error, Mr. Rutherfurd takes a double image of each 
luminous body by stopping the motion of the telescope 
for about half a minute between the first and second ex- 
posure, so that each star is represented by two con- 
tiguous points on the negative, a peculiarity which dis- 
tinguishes them from any spot formed accidentally on the 
film. By this means a very correct though very delicate 
map of the heavens is obtained, from which trustworthy 
measurements may be made. Professor Peirce says with 
justice this addition to astronomical research is a step 
which leaves far behind it all that has been previously ac- 
complished. Photographs preserve for comparison with 
future researches the exact relative positions of the stars 
at the present time. The photographs once taken con- 
stitute indisputable facts beyond the influence of any 
personal defect of observation, and provide for future 
ages the present actual position of the stars. 



26o THE APPLICATIONS OF PHOTOGRAPH V. 

Mr. Asaph Hall, who has taken part with Professor 
Bond in measuring the photographic images as well as in 
the calculations of these measurements, has quite recently 
submitted the photographic method to severe tests 
in order to determine its value in its application to the 
observation of the transit of Venus. He seems not to 
approve of photography as applied to observations 
of the stars from its want of rapidity; but he admits 
that in the case of an eclipse of the sun, or of the 
passage of a planet across the sun's disc, it possesses very 
great advantages, especially for the observation of the 
exterior or interior contacts of the planet with the sun's 
limb, and that any error to which it may be liable is 
worthy of the most serious investigation. The observa- 
tion of the contact is uncertain in consequence of the 
irradiation ; it only lasts for an instant, and should 
the observer fail to notice it, the registration of the 
phenomenon is irredeemably lost at that particular 
station, and all the long and expensive preparations are 
rendered useless. 

On the other hand, when the sky is clear a photo- 
graphic image can be obtained in an instant, and can be 
repeated during the whole course of the transit; and 
when even the contacts have not been caught, results not 
less valuable may be obtained if the data collected on 



ASTRONOMICAL PHOTOGRAPHY. 26 1 



the photographic plates can be correctly calculated. Of 
this we shall shortly show the perfect practicability. We 
may announce for certain that the transit of Venus will be 
depicted by photography, for in England, in France, in 
Russia, and in America, much activity is displayed in 
making preparations to obtain photographic pictures of it.' 

Nothing can more solidly establish the right of photo- 
graphic observations to be considered one of the most 
important aids of scientific research than the accounts 
of the last eclipses of the sun. It will be recol- 
lected that in i860 for the first time the solar origin of 
the protuberances was put beyond doubt solely by photo- 
graphy, which preserved a faithful representation of the 
movement of the moon in relation to these protuber- 
ances. 

The photographs of Tennant at Guntoor, and of 
Vogel at Aden in 1868, and those also of the American 
astronomers at Burlington and at Ottumwa, Iowa, in 1869, 
under the superintendence of Professors Morton and 
Mayer, have fully confirmed these conclusions. 

It was also in the same manner that the great pro- 
blem of the solar origin of that part of the corona which 

• As the reader is doubtless well aware,, the attempts to photograph 
the Transit were eminently successful, especially with the daguerreotype 
-process. 



262 THE APPLICATIONS OF PHOTOGRAPHY. 

extends more than a million of miles beyond the body of 
the sun was definitively solved by the photographic 
observations of Colonel Tennant and Lord Lindsay in 
1 87 1, after having for many years furnished matter for 
numerous discussions. 

If photography, as will be seen by these striking facts, 
now renders great services to astronomy, it will in all pro- 
bability render yet greater in the immediate future, for it 
is still unable to depict all the celestial bodies. 

* The nebulae and the comets,' says Mr. Warren de 
la Rue, 'have not fallen into the domain of this art, 
though perhaps no branch of astronomy would have more 
to gain if we could succeed in extending this mode of 
observation to these bodies. In theory, and even in 
practice, there is no limit to the sensitiveness of a photo- 
graphic plate. At the same time, there still exist great 
difficulties in photographing the planets, which it is 
necessary to overcome before photography can for any 
special purpose reproduce their phases and their physical 
characteristics, but even in this also there is great hope of 
final success. The chief obstacle to success arises from 
atmospheric currents which continually change the posi- 
tion of the image on the sensitive plate. The structure 
of the sensitive film is also a cause of trouble with very 
small objects, though a photograph taken at Cranford some 



ASTRONOMICAL PHOTOGRAPHV. 26^ 

time ago of the occultation of Saturn by the moon, shows 
the ring of the planet in such a manner as to afford great 
hopes for the future.' 

No doubt science will succeed in triumphing over 
these obstacles, and photography applied to the whole 
heavens will crown the edifice of modern astronomy. 

Some astronomers, however, are not of this opinion, 
and we believe it may be useful to state the opinions ot 
the venerable Maedler, formerly director of the Obser- 
vatory of Dorpat, on the subject of photographic 
astronomy : — ' The greater number of those who hear 
me,' said the great astronomer, in a lecture given in 1868, 
* may still remember that immediately after the discovery 
of photography we heard hopes expressed which re- 
sembled nothing so much as those of Descartes and his 
contemporaries after the discovery of the astronomical 
telescope. They compassionated the unfortunate philo- 
sophers who had passed all their lives without interrup- 
tion in observing, in measuring, and in drawing. 

* Not only would the same thing, they said, be done 
without trouble and in much less time, but the results 
obtained would be much superior, much more exact, and 
much more detailed than formerly. What has taken me 
seven years, the determination of the extent of the sur- 
face of the moon, would be better done in seven seconds. 



264 THE APPLICATIONS OF PHOTOGRAPHY. 

Now thirty years have elapsed since the discovery of 
Daguerre, how many of these ambitious hopes have been 
fulfilled ? 

' Warren de la Rue, in England, and William Cranch 
Bond, in America, have courageously put their hands to 
the work. They have adapted powerful astronomical 
telescopes to photographic apparatus, they have also 
succeeded in giving to their instruments a motion corre- 
sponding to that of the celestial bodies, of which they 
propose to produce the image during the short time 
necessary for the production of the impression. 

' Thus the moon has been photographed in her 
different phases, but the details are still inferior to those 
which an able observer can determine. Bond has been 
engaged with the fixed stars ; he made use of an astro- 
nomical telescope which enabled him to perceive the stars 
of the fourteenth magnitude, but he was only able to 
obtain weak and scarcely visible images of those of the 
fifth magnitude, 

' We could mention, it is true, very valuable pictures 
which we owe to astronomical photography ; but it is not 
the details of the starry heavens which can be acquired 
and preserved in this manner, but the phenomena con- 
nected with objects long known and giving a powerful 
light. 



ASTRONOMICAL PHOTOGRAPHY. 265 



* I shall mention in the first place the spots on the 
sun, the representation of which only requires the smallest 
fraction of a second, and which have been produced 
with great exactness. But, even in this^case, details have 
not been obtained, such as good observers, accustomed to 
these phenomena, have been able to produce, but there 
is obtained, what is very important in this case, an image 
of the sun at a specified moment, and, if we may be per- 
mitted to use an expression of Sir John Herschel, we 
compel the sun to write its own history. 

* These experiments will be, or, to speak more cor- 
rectly, have already been, very useful in total eclipses of 
the sun. There is no draughtsman, however expeditious 
he might be, who could, during two or three minutes, 
the ordinary duration of the phenomenon, do what Warren 
de la Rue did in Spain at the last eclipse of the sun, 
because, if everything has been prepared, there can be 
obtained not only three but twelve or fifteen images of 
a phenomenon which passes away so rapidly. 

* As for the planets, even the larger ones, photography 
is of little use, and will teach us very little that is new. 
It will be of still less use when applied to the fixed 
stars. The groups of the Pleiades and of Orion have 
been photographed, and these constellations may cer- 
tainly be recognised in the images obtained, but a good 



266 THE APPLICATIONS OF PHOTOGRAPHY. 

eye, even without the aid of lenses, will see more in the 
heavens than is shown by photography.' 

We have considered it right to repeat these severe 
criticisms of Maedler without altogether admitting their 
correctness. We think, on the contrary, that photography 
is one of the great resources of modern astronomy. 

There is nothing so hurtful or so fatal to progress, 
says Mr. Warren de la Rue, as false data, because they 
are sometimes perpetuated for ages.^ 

The prodigies accomplished by modern opticians 
will be continued by our descendants, and the magnifi- 
cent telescopes of our observatories, which diminish the 
apparent distance of the moon to such an extent that 
we can now study the constitution of our satellite as if it 
were at a less distance than three hundred miles, are 
only as yet, we cannot doubt, specimens of the infancy 

* It cannot be denied that a photographic impression of any object is 
infinitely inferior to the object as we see it with the naked eye, whether 
the object be celestial or terrestrial. Nevertheless, photography has already 
done much, and is full of the highest promise of future achievements as 
the only known means by which may be preserved an absolutely trustworthy 
register of many of the most important phenomena of the heavens. It 
has furnished the astronomer with charts of the moon ; the phenomena 
connected with solar eclipses ; the positions of the spots on the sun's disc 
at certain fixed dates ; the spectra of heavenly bodies, showing in unerring 
lines the presence, in their luminous envelopes, of certain elements which 
are known to us. Without the aid of photography, the lines in the solar 
spectrum could not have been fully observed, as the photograph reveals 
many lines which are invisible to the naked eye. — Ed. 



ASTRONOMICAL PHOTOGRAPHY. 26/ 

of an art which reckons among its founders GaHleo and 
Newton 

When the science of astronomical optics has accom- 
plished still more, photography, closely following its 
footsteps, will produce marvels of which the boldest 
imagination can hardly have a suspicion. * There is no 
limit to the sensitiveness of a photographic plate,' 
we may say at present with an eminent astronomer ; 
consequently the images of the orbs of heaven fixed in 
the focus of the camera will, perhaps, permit us to study 
the most minute details of the geology of the planetary 
bodies. 

If it be true, as Leibnitz says, that the present is big 
with the fate of the future, we shall comprehend, by the 
importance of results already obtained, what we have a 
right to expect may be attained by the astronomers of 
the future. 



268 THE APPLICATIONS OF PHOTOGRAPHY. 



CHAPTER VIII. 
PHOTOGRAPHIC REGISTERING INSTRUMENTS. 

IMPORTANCE OF REGISTERING INSTRUMENTS — PHOTOGRAPHIC BARO- 
METERS AND THERMOMETERS — THE REGISTRATION OF THE VIBRA- 
TIONS OF THE MAGNETIC NEEDLE — RONALD's PHOTO-ELECTROGRAPH 
— PHOTOGRAPHIC PHOTOMETRY — PHOTOGRAPHY OF COLUMNS OF 
WATER RAISED BY A TORPEDO — OF THE PHENOMENA OF THE 
INTERFERENCE OF THE RAYS OF THE SPECTRUM. 

Among the physical sciences there are some, of which 
the progress is, so to say, intermittent, which burst out 
into veritable revolutions which suddenly transform them; 
there are others, where great events are rare, where the 
long-continued patience of the observer is, to a certain 
extent, a substitute for the inspiration originating ac- 
cidentally in the brain of an inventive genius. 

Chemistry has had its Lavoisier, who, by the theory 
of combustion, by the analysis of the atmosphere, sud- 
denly marked a new era in this fertile branch of human 
knowledge. 

Physical science has had its Volta, who opened 
to it a new horizon by originating the electric pile. But 



PHOTOGRAPHIC REGISTERING INSTRUMENTS. 269 

there are other sciences where such progress cannot be 
suddenly manifested. 

Meteorology, for example, which has for its object to 
study the laws of the mechanism of the atmosphere, 
ought to determine every day the temperature, the 
humidity of the air ; note the variations of the baro- 
meter, the oscillations of the magnetic needle ; the domain 
in which it acts is not that of rapid conquests ; a science 
of observation, it cannot expect anything from the for- 
tunate accidents which sometimes occur when making 
experiments. 

The work of those who devote themselves to it con- 
sists essentially in gathering up each day and every hour 
rigorously exact lists of figures ; the hope which animates 
them is to see stations of observation multiplied over 
every continent. They will leave to their successors the 
patient investigations made during their lives — happy if 
correlation and comparison of their results lead to the 
discovery of some of the fundamental laws which pre- 
side over the movements of the atmosphere. 

In presence of the necessity of consulting, as fre- 
quently as possible, and at an increased number of 
meteorological stations, the various instruments by which 
the atmosphere is questioned, it was soon observed 
that there would be a very great advantage in substituting 
for the labour of man that of machines. 



2/0 THE APPLICATIONS OF PHOTOGRAPHY. 

How can we conderrin an 5bser\*er, however con- 
scientious he may be, to read off several times every 
hour and for entire days together the degree of the 
thermometer, the height of the barometer, to take a note 
of the movements of the magnetic needle and the rota- 
tions of the weathercock ? But it is of importance to 
the progress of meteorology that these daily observa- 
tions be executed with the precision which ought to 
characterise every truly scientific document. 

What man cannot do is accomplished by a machine. 
To obtain this ingenious mechanism capable of leaving 
on paper traces of the movement of the mercury in the 
barometer and the thermometer at every hour of the 
day and of the night, of indicating the slightest disturb- 
ance which may occur in the most delicate parts of 
the most exact instruments, recourse has been had 
to the valuable aid of photography. The art has 
been applied to those meteorological instruments 
which write down their own variations at every moment, 
and which are called self-registering. 

The idea of employing for the study of meteoro- 
logical phenomena apparatus so arranged that they may 
themselves mark the traces of the influences to which 
they are subjected is not new. It goes as far back as 
Magellan, who, in 1782, had constructed thermometers 



PHOTOGRAPHIC REGISTERING INSTRUMENTS. 27 1 

and barometers which registered all the changes caused 
by the variations of the state of the atmosphere. 

Registration by photography, such as is now accom- 
plished in a great number of observatories, offers the 
advantage of doing away with the complicated mechan- 
ism which every other method required, whether me- 
chanical or by electro-magnetism. This mode of 
registering is chiefly utilised for the variations of the 
barometer and the thermometer, and the oscillations of 
the magnetic needle. 

It is well known that at the upper surface of the 
column of mercury in the barometer there is an 
empty space known as the Torricellian Vacuum. If a 
light be placed — that of gas or of a petroleum lamp for 
example — before the barometer and a convex lens between 
them to converge the rays of light on the upper part of 
the tube of the barometer, an image of the lighted 
space immediately above the mercury would be thrown 
upon a piece of sensitised paper placed behind it, and 
this image would vary at each instant with the varia- 
tions of the level of the mercury of the barometer. 

The registering thermometer or thermograph is 
arranged almost in the same manner, only it is necessary 
that the lamp should be placed at some distance from 
the apparatus in order that the heat emitted by it may 



272 THE APPLICATIONS OF PHOTOGRAPHY. 

not act upon the instrument ; besides this the light does 
not pass through the empty space above the mercury, 
but through a small bubble of air which has been pre- 
viously introduced into the thin mercurial column. The 
light thus transmitted produces a mark like a point on 
the paper. 

In these instruments the sensitised paper is stretched 
on a drum which regularly revolves by means of clock- 
work, and the traces of the variations of the height of 
the mercury in the barometer and the thermometer are 
found marked by a continuous line, when the paper is 
withdrawn and submitted to the operations necessary to 
fix the image. 

The arrangement of the mechanism varies according 
to the mode of registering applied to different instru- 
ments. In order to adapt photography to the registra- 
tion of the variations of the barometer, Mr. Ronalds, 
and afterwards Mr. Salleron, have adopted the ingenious 
arrangements which we shall describe. 

This self-registering barometer has been called the 
photographic barometrograph. 

An ordinary cistern barometer is suspended ver- 
tically by an iron collar. Before this instrument is a 
convex lens which concentrates the light of an argand 
lamp or a jet of gas on its upper part. The upper part 



PHOTOGRAPHIC REGISTERING INSTRUMENTS. 273 

of the tube of the barometer is provided with a 
transparent scale of glass divided into fiftieths of an 
inch. 

The luminous ray passes through this scale and 
above the surface of the mercurial column, and then 
through an achromatic object-glass, projecting on to a 
sheet of sensitised paper the image of the graduated 
scale, and also of the movable surface of the mercury. 

The photographic paper is fixed to a frame which 
moves upon a carrier in a plane at right angles to the 
axis of the object-glass. Clockwork is applied to the 
frame so that it moves its own length in twenty-four 
hours. 

It results from the whole of these arrangements, says 
M. Pouriau, to whom we owe an excellent work on self- 
registering instruments, that the light thrown on the 
tube of the barometer is arrested by the mercurial 
column forming a screen the image of which, pass- 
ing through a lens, falls upon the sensitised paper. 
The representation of the convex or concave surface 
of the mercury, and the divisions of the scale as marked 
upon the tube of the barometer, are at the same time 
thrown upon the sheet of paper which receives their 
images through the opening admitting the rays of light 
from the lamp. This sheet of paper fixed to the carrier 

T 



274 THE APPLICATIONS OF PHOTOGRAPHY. 

partakes of its movement, and from this it follows that 
each part of it comes in succession before the opening 
and is impressed with the image. 

At the close of each day the sheet of paper is taken 
out of the frame ; the impression is then fixed by the 
ordinary photographic process ; the part affected by the 
luminous rays forms an undulating line drawn by the 
upper surface of the mercurial column, the height of 
which is easily measured by the divisions of the scale 
printed upon it at the same time. 

After the impression has been fixed on the paper 
a sheet of glass is applied to it divided by lines into 
twenty-four equal parts, and if the hour is known at 
which the operation commenced, it is easy to determine 
with the most perfect exactness the hour corresponding 
to all the points of the line. 

When a photographic registering thermometer is 
required, in place of the tube of the barometer of which 
we have been speaking, a thermometer having the 
divisions of the scale cut upon glass is used. The 
upper surface of the mercury and the divisions of 
the scale are again photographed at the same time. 
The thermometer is curved in such a manner as to 
allow the bulb being passed through an opening in the 
wall of the room, and thus exposed to the influence 




o < 

a 



PHOTOGRAPHIC REGISTERING INSTRUMENTS. 275 

of the external temperature which it is intended to 
measure. 

M. Salleron has recently constructed, for the Obser- 
vatory at Kew, a very fine photographic self-registering 
apparatus for the variations both of the barometer and 
the thermometer at the same time ; after what we 
have just said, a description of it will be easily under- 
stood. 

The arrangements of this apparatus are represented 
on the right and left of the engraving, fig, 62. 

The mercurial barometer is at the middle of the 
table, its upper part being represented at I. O is the 
object-glass of the photographic camera. H is the clock- 
work which moves the slide carrying the photographic 
paper by means of the rod P. 

This magnificent apparatus leaves far behind it all 
previous arrangements ; for not only does it act as a 
barometrograph, but it also registers the temperature 
and the hygrometrical variations. 

The thermometrograph is shown to the right of our 
engraving. It is upon a different plan to that of 
which we have just spoken. The metallic reservoir of 
air, a, is sunk into the earth, and remains at a constant 
temperature ; it is hollow and communicates by a tube 
with one of the branches of a tube which is filled with 



2/6 THE APPLICATIONS OF PHOTOGRAPHY. 

mercury, and rises between the light and the object- 
glass, O. The other branch of the tube is in connection 
with a second reservoir of air, b, which remains in the 
surrounding atmosphere. The difference of the tem- 
peratures of the two reservoirs of air is shown by a 
movement of the mercury in the glass tube, the light 
passes over the surface of the fluid metal and impresses 
the photographic paper after passing through the object- 
glass O. It traces upon the moving photographic paper 
an undulating line which represents the variations of the 
mercury in the tube, and consequently the temperature 
of the air. 

Another similar arrangement, a' and b\ acts as a 
registering psychrometer or measurer of the am.ount of 
watery vapour in the atmosphere. The reservoir of air, a! , 
is sunk in the earth, the other reservoir, b\ which is kept 
moist, remains exposed to the atmosphere ; both again 
communicate by means of a tube with two branches of 
a glass tube containing mercury, over the surface of 
which the luminous rays pass. 

Photography is not only applied to the registration 
of the variations of the barometer and thermometer, 
it may also be made use of to register the declination of 
the magnetic needle, as Dr. Brooke has proved by 
the construction of an apparatus equally ingenious as 




Fig. 63 



[Page 277 



PHOTO-ELECTROGRAPHIC IIjf.STRUMENT AT KEW OBSERVATORY, FOR REGISTERING 
THE STATE AND VARIATIONS OF THE EUKCTRICITV OF THE A'R. 



PHOTOGRAPHIC REGISTERING INSTRUMENTS. 277 

correct, and which is constantly in use at the Observatory 
at Greenwich. 

The magnetic needle carries at its extremity a very 
small mirror on which the light of a lamp falls. The re- 
flected ray is thrown upon a piece of sensitised paper 
placed in a camera, and it there traces an arc greater or 
less in proportion to its distance from the photographic 
paper. If the magnetic needle makes the slightest move- 
ment, the mark of the reflected ray changes its place 
upon the screen — it follows faithfully the motion of the 
needle, and does not fail to note its least oscillation. 

The sensitive paper is not fixed, but is attached to a 
cylinder which performs one revolution upon its axis in 
twenty-four hours. At each moment the reflection of 
the mirror is traced upon the photographic sheet, which 
at the end of the day is developed and fixed by the or- 
dinary processes. 

Thus, there is obtained a continuous line which in- 
dicates the movements of the luminous ray reflected by 
the mirror attached to the magnetic needle, and which 
shows its slightest motion during the course of the 
twenty-four hours. 

At the Observatory at Kew, an analogous system is 
made use of to register the variations of the electrical 
condition of the atmosphere. The photo- electrograph 



2/8 



THE APPLICATIONS OF PHOTOGRAPHY. 



Fig. 64. 



(fig. 63) consists of a lightning conductor in connection 
with an ordinary electroscope, the gold leaves of which, 
as is well known, are separated more or less from one 
another according to the greater or less quantity of free 
electricity in the air. 

The leaves of gold illuminated by a lamp as seen in 
our engraving intercept the light and 
throw the shadows on the sensitive 
paper, which has a regular down- 
ward motion, produced by clock- 
work. Thus are obtained two un- 
dulating lines which .approach or 
separate at eveiy hour of the day, 
and show with absolute correctness 
the electric state of the atmosphere 
at every moment (fig. 64). 

It is to Francis Ronalds that the 
honour of having invented this ad- 
mirable system of registering be- 
longs ; this photo-electrograph, as we 
have said, is used at Kew, and 




"oN^T^BCAR^rE'rorTHK marks down night and day, and 

ELECTROGRAPH. _ ^ ^1 1 • 1 i. ^ 

from year to year, the slightest 
changes in the electrical state of the atmosphere. 



PHOTOGRAPHIC REGISTERING INSTRUMENTS. 279 

Photometry is another branch of physical science 
which has found a powerful assistant in the operations 
of the photographer. 

When it is desired to measure the intensity of two 
sources of light, they are made both to shine at the 
same time, and the strength of the lights measured 
by the comparative depth of their shadows. But 
how can such a measurement be accomplished if 
the two lights cannot be got to shine at the same 
time .'* 

Though the comparison is easy between the light of a 
candle and that of a lamp which may both be made to 
burn at the same time, how is the student to act if he 
would measure the relative power of the light of the 
sun and that of the stars oi of the moon } The* only 
means of solving a problem so delicate is by photo- 
graphy. 

If a piece of sensitised paper be exposed to the in- 
fluence of the image formed at the focus of a lens by 
any source of light, will not the amount of alteration 
produced on the sensitive surface serve to measure the 
intensity of the light emitted .-* ' The traces of the 

* ' Intensity of light ' is a relative phrase which may refer indefinitely, 
either to the illuminating power or to the photogenically actinic power 
of rays of light. Photography supplies an accurate test for the illuminating 



28o THE APPLICATIONS OF PHOTOGRAPHY. 

luminous source are no longer fugitive like the shadows 
thrown on the scale of the ordinary photo-meter ; it is 
durable and permanent, and can be compared with 
that produced by another light shining at a different 
time. 

Photographic photometry has enabled science to com- 
pare the luminous intensity of the solar rays with that of 
the moon. The orb of day gives a light three hundred 
times greater than that of the orb of night. Thanks to 
these processes physical science has been enabled to 
trace out a new course in domains considered inac- 
cessible before the advent of photography. 

Herschel and Edmund Becquerel have been able to 
study effectually the peculiarities of the solar rays at 
different hours of the day; and thanks to the employment 
of photographic paper, the study of the chemical action 
of light to which these distinguished philosophers have 



power of white light ; but when a ray of white light is broken up and the 
photographer attempts to test any of the resulting primary or secondary 
colours of the spectrum, his observations will afford him no guide to the 
illuminating power of the light. Thus, for example, a luminous homo- 
geneous yellow light will have no more effect on the sensitive plate than 
if he had attempted to photograph an object in pitchy darkness; whereas the 
presence of blue or violet rays, however feeble or imperceptible to the 
naked eye, may at once be detected by their action on the photographic 
plate. — Ed. 



PHOTOGRAPHIC REGISTERING INSTRUMENTS. 28 1 

devoted their attention has assumed a place among the 
most interesting chapters of modern science. 

It may be seen by the brief description we have 
given of the admirable instruments which are employed 
at some of our observatories how valuable registration 
by means of photography is, since it enables us to obtain 
exact and continuous observations ; but these instruments 
are only the birth of yesterday — their use is not very 
extended, and they will certainly be soon modified 
and give place to arrangements still more complete and 
ingenious. 

Besides these purposes, photographic registration 
may be applied to other instruments of observation. 
For example, there is nothing to prevent the rain-gauge 
being furnished with an arrangement which would show 
the variations of its level by means of a tube in connec- 
tion with the receiving vessel. 

The future will prove that registration is the funda- 
mental base of meteorological science, which can never 
establish its laws unless they are supported by continuous 
observation. The luminous ray will write in silence the 
movements and the variations of all the apparatus ; the 
observer will only have to come once each day to con- 
sult the sensitised registers, where Nature will, so to say, 
have marked with its own seal the periodical or inter- 



282 THE APPLICATIONS OF PHOTOGRAPHY. 

mittent changes to whose mysterious influences it is un- 
ceasingly subject. 

It must not be supposed, after what we have said, that 
the photographic system is the only one that can be em- 
ployed for the registration of atmospherical phenomena : 
we have only spoken of it because it is in more im- 
mediate connection with our subject ; and besides, it 
abounds, as will have been seen, in new and curious 
appliances. 

It may be necessary to add, in order to give the 
reader a more complete idea of meteorological registra- 
tion, that in addition to the photographic system, science 
has often recourse to two other methods ; one being based 
upon mechanical, and the other upon electro-magnetic 
arrangements. 

The first consists in finding in the variations which 
the instruments experience, the power required to put 
the registering pencils in motion in such a manner 
as to enable them to leave their marks. This system 
is the most ancient, but it is applied with diffi- 
culty in consequence of the small amount of force 
which is at command. The second, as its name 
implies, is based on the employment of dynamic 
electricity. 

The employment of registration by photography 



PHOTOGRAPHIC REGISTERING INSTRUMENTS. 283 

offers, in a great number of cases, very decided advan- 
tages ; but in France there has been considerable opposi- 
tion shown to this system, which is not represented in 
our country as it deserves. 

The example given by the directors of the Kew 
Observatory, who have multiplied photographic regis- 
tering apparatus, and daily use with success and 
advantage these valuable instruments, should cause 
our philosophers to have recourse to them more fre- 
quently. 

Photography is also capable of furnishing to science 
means of measurement quite new and unexpected. 
The 'Journal of St. Petersburg' quite recently in- 
formed us that instantaneous photography has been 
utilised by Lieutenant Abnet in some military experi- 
ments, where it was wished to calculate the projective 
force obtained from explosive substances of different 
natures which are used to fill the torpedo and submarine 
bombs. In these experiments the torpedo was buried 
in the sand at low water, and exploded by an electrical 
current at high water. By means of photography an 
observation was taken of the height of the column of 
water thrown into the air, and then at low water again 
they observed the extent of the crater formed by each 



284 THE APPLICATIONS OF PHOTOGRAPHY. 

explosion in the sand. In each experiment the photo- 
graphic camera did its duty in a most satisfactory- 
manner. 

Even the delicate optical phenomena of the inter- 
ference and the diffraction of light have been depicted 
by photography. Not long ago Professor Clinton 
showed to his students at the Clarendon laboratory 
at Oxford a fine series of photographic impressions of 
the phenomena of interference and diffraction. 

These photographs were obtained by receiving the 
rays of interference on prepared plates instead of the or- 
dinary screen, and then the image was thrown upon a 
screen in the lecture room by means of the oxyhydrogen 
light. The impression produced on the sensitive plate was 
sometimes magnified 2,500 diameters. The subjects thus 
photographed and thrown upon the screen comprised the 
phenomena of interference produced by Fresnel's prism, 
the rays of diffraction by thin edges, the shadows of a 
straight edge and of an angular aperture, the rays of in- 
ternal interference in the shadow of a thin wire and of a 
needle in a small circular disc of light, and the pheno- 
mena presented by light when passing through a small 
circular hole. The professor expressed his conviction 
that it was the first time photography had been taken 
advantage of for such public demonstrations. 



PHOTOGRAPHIC REGISTERING INSTRUMENTS. 285 



Photography also offers great advantages to the 
chemist and to the natural philosopher in studying the 
rays of the spectrum. 

An American, Mr. H. Draper, has recently applied 
photography to the examination of the violet rays, 
and also to the space beyond them ; he has been 
able to reveal some new rays until now unknown. He 
has besides shown that several rays which were consi- 
dered to be simple are in reality double or triple. 

But the English scientist, Mr. Norman Lockyer, 
has gone still farther ; he has made use of the photo- 
graphy of the rays of the spectrum to create the 
new method of analysis, as ingenious as it is practical, 
now made use of at the London Mint to examine the 
alloys of gold and silver. 

The alloy of gold and silver is placed in a cavity 
made in the lower piece of charcoal of an electric lamp 

(fig. 65). 

It is then volatilised when the Voltaic current is put in 
motion ; the luminous pencil of rays passes through an 
opening, O, which is seen enlarged at o', and the rays 
from the gold and silver thrown upon a plate in a 
camera are photographed directly as indicated in our en- 
graving. The photographs obtained, compared with 
those previously produced by rays of light from alloys of 



286 THE APPLICATIONS OF PHOTOGRAPHY. 

known composition, serve to determine the proportion of 
gold and silver combined in the alloy examined, it being 
well known that the breadth and length of the image 
varies in proportion to the number of substances 
entering into the composition of the alloy. 



28/ 



CHAPTER IX. 

THE STEREOSCOPE. 

A FEW WORDS ON STEREOSCOPIC VISION — MEANS OF MAKING PHOTO- 
GRAPHIC PRINTS APPEAR IN RELIEF— WHEATSTONE'S STEREOSCOPE 
— MONOSTEREOSCOPE — HOW STEREOSCOPIC PHOTOGRAPHS ARE 
PRODUCED. 

Our intention is not to describe the stereoscope here in 
its relation to optics ; we shall merely refer to it as con- 
nected with photography. 

We consider it right, however, to give some short 
account of an instrument which enables us to see a 
design drawn upon a flat surface appear as if it were in 
relief. 

Our eyes show us objects as they are in relief ; they 
are not seen by us as if traced on a plane surface, they 
appear solid and raised. 

The study of the laws of vision shows that this effect 
is produced by two images seen simultaneously, one 
being perceived by each eye. Here is an experiment 
easily made which will show this at once. Place before 
your eyes a book in a vertical position so that the back 



288 THE APPLICATIONS OF PHOTOGRAPHY. 

of it is visible. Shut the right eye and open the left, 
and you will see the left side of the book. After this, 
if you shut the left eye and open the right, then the 
back and the right side of the book only will be seen. 
In order to make the experiment more striking, if a 
sheet of white paper be stuck on one side of a book 
bound in red or any other colour, the white or the coloured 
side will be seen alternately, according as the right or 
left eye is opened ; when both eyes are open, both sides 
will be seen. The experiment may, in the same way, 
be made with a cube or a quadrangular pyramid (fig. 66). 
Both the right and left faces are seen when both eyes 
are open, and according as the right or the left eye is 
shut the cube or the pyramid assumes the appearance of 
our figures on the right and left. Our minds by the 
force of habit combine the two pictures, and this gives 
the impression of relief or of being raised or solid. 

To make use of a stereoscope, that is an instrument 
which gives to a picture on a flat surface the appearance 
of being in relief, it is necessary to take two impressions 
of the picture so that each impression represents the 
object to each eye as the solid object itself would. 

One of the first stereoscopes given to the public was 
that invented by Wheatstone. This instrument is con- 
tained in a rectangular box. Two views of the same object, 



THE STEREOSCOPE. 



289 



represented according to the principles of stereoscopic 
vision, are placed in grooved slides, one at each side of 
the box ;* two small mirrors are fixed at right angles to 
one another in the centre of the box ; the eyes of the 

Fij?. 66. 




® : 





observer, being situated a little in front of the mirrors, 
will see the pictures at the sides reflected from them, 
and when the eyes are at the proper distance, the two 

' It is not generally known that in taking a photo-micrograph of 
minute invisible crystals, or of any microscopic preparation standing out 
in relief, in order to obtain a perfect stereoscopic photograph of the object, 
neither the camera nor the preparation need be moved. The stereoscopic 
relief may be obtained by first taking a picture with the light on one side, 
and then taking a second picture with the light on the other side of the 
object. — Ed. 

U 



290 



THE APPUCATIONS OF PHOTOGRAPHY. 



pictures as reflected and viewed through lenses will ap- 
pear as one, and in relief. 

Brewster's stereoscope (fig. 67), and that of Heimholtz 
(fig. 68), are on somewhat different principles, and are 
considered to be improvements on Wheatstone's. Every 









BREWSTER S STEREOSCOPE. 



one has looked at photographs through such instruments ; 
their management is too simple and their use too com- 
mon to require us to spend any time in describing them. 
The stereoscope was invented at about the same 
time as the daguerreotype. At first it was used for the 
purpose of viewing pictures drawn by the hand, but on 



TIIK STEREOSCOPE. 



291 



the discovery of photography the two new arts lent each 
other mutual support ; they became so intimately con- 




HEIMHOLTZS STEREOSCOPE. 



nected that now the stereoscope and the photograph 
appear to be almost two parts of the same instrument. 



u 2 



292 THE APPLICATIONS OF PHOTOGRAPHY. 



In 1858 an able operator, M. Claudet, invented a 
very curious kind of stereoscope which can be seen by 
several people at the same time. This instrument con- 
sists of a dark screen the centre of which has been cut 
out and the space occupied by a piece of ground glass ; 
by means of two magic lanterns, two images of the 

Fig. 69. 




MONO-STEREOSCOPIC PRINT. 



same object are thrown upon this, and are so combined 
as to give the impression of the picture being in relief, 
without the necessity of viewing it through any optical 
instrument (fig. 69).^ 

' This method of combining stereoscopic pictures is not so successful 
as to command extensive application. — Ed. 



THE STEREOSCOPE. 



293 



The facility of procuring by means of photography 
views so delicately printed by Nature herself has 
singularly contributed to the perfecting of the stereo- 



Fig. 70. 




FEVRIERS PILLAR STEREOSCOPE, 



scope, which is now manufactured with admirable cor- 
rectness. 

After Brewster's stereoscope, the Pillar Stereoscope 
(fig. 70), invented by M. Fevrier, gives to photographs 



294 THE APPLICATIONS OF PHOTOGRAPHY. 



such an appearance of relief, and so enlarges them, that 
nothing can better represent natural objects. 

In this apparatus, with the eyes fixed upon the lenses, 
by turning a small button causing the rotation of an 
axis, around which the stereoscopic photographs are 
arranged, Switzerland, the Pyrenees, China, Japan, 
come one after the other under the view of the observer, 
who can admire, without stirring from his chair, distant 
places, even those most inaccessible to the traveller. 

We now come to the processes employed in producing 
photographic impressions suitable for being viewed 
through the lenses of the stereoscope. 

The photographic picture should be double, that is 
to say, it is necessary to take two views of the same 
subject ; these two views ought to be identical in their 
central parts, but differ a little at their sides. To attain 
this result a first view is taken of the object by placing 
the photographic camera towards the right, and then a 
second view is taken after moving it a little to the left. 

To give greater correctness to the impressions two 
views are generally taken at the same time by two dis- 
tinct cameras, having lenses of uniform focus, fastened 
together by a movable slide fixed on the top of a 
tripod. 

If it be wished to take two stereoscopic pictures of 




U'age 295 



APPARATUS FOR OBTAINING THE TWO PROOFS OF THE 
STEREOSCOPE. 



THE STEREOSCOPE. 295 

an object, such as a picture or a statue, the two cameras 
are placed at about the distance of ten feet from the 
model, and are separated from each other by about six 
inches. Care must be taken before introducing the 
collodionised glass into the cameras that the inclination 
of the two images in the foci of the cameras is such 
as will produce the desired effect. For this purpose 
it must be ascertained that the point of the object which 
is in the centre of the ground glass of the camera to the 
right be also exactly in the centre of the ground glass 
of that to the left. This fundamental observation being 
once made, the photographs are taken in the ordinary 
manner. The apparatus ready for use is represented in 
figure 71. Figure 73 gives the facsimile of a stereo- 
scopic slide formed of two photographic views placed 

Fig. 72, 




PLATE FOR SUPPORTING THE CAMERA WHEN TAKING STEREOSCOPIC VIEW. 

beside one another under the conditions suitable tor 
stereoscopic vision. 

It is a good plan to print the positives for the stereo- 
scope upon glass ; the transparency of the glass lights 



296 THE APPLICATIONS OF PHOTOGRAPHY. 

up the picture better and helps to give it relief and 
solidity.* 

When it is wished to take stereoscopic views of land- 
scapes, buildings, or of distant objects in general, only one 
view is taken at a time with one camera. This camera 
rests upon a plate on which it moves easily from right to 
left guided by two squares which move in a groove as 
seen in fig. 'J2. A first view of the subject is taken by 
placing the camera at the right side of the plate, care- 
fully observing the object which is in the centre of the 
ground glass of the camera. This view having been 
taken, the camera is moved to the left of the plate and 
carefully adjusted so that the same object is again in 
the centre of the ground glass, though the lens has 
changed its position ; a second view is then taken. The 
two positions occupied by the camera are separated by 
about three inches, a distance which nearly corresponds 
with that of the pupils of the human eyes. 

' The position of the two pictures taken in this way must be reversed 
when printed and mounted on card. — Ed. 



297 



CHAPTER X. 

PHOTOGRAPHY AND ART. 

IS PHOTOGRAPHY ART ?— ITS USES IN RELATION TO PAINTING 
REPRODUCTION OF ENGRAVINGS — VOYAGES OF DISCOVERY— PHO- 
TOGRAPHY BY THE MAGNESIUM LIGHT— PHOTOGRAPHIC PORTRAITS 
CONSIDERED AS HISTORICAL DOCUMENTS. 

Painters are not generally carried away by their ad- 
miration of photography; its physico-chemical processes 
seem incompatible with the sentiments which animate 
them ; they feel repugnance in placing collodion beside 
a palette of oil colours. Many, indeed, are very severe 
upon the art of Daguerre ; there are some who cannot 
hear a photographic print praised without feeling much 
annoyed. 

Photography, they say, composes -nothing ; it only 
gives a copy, a mere imitation, brutal in its truth. It 
wants sentiment, no flame of genius gives it life. It is 
awkward, it gives an equal value to important parts and 
to accidental details. 

If it takes a portrait it copies its model unskilfully ; 
it represents the ornaments of a dress better than it can 



298 THE APPLICATIONS OF PHOTOGRAPHY. 

give the expression of a face ; the eye of the sitter is not 
given better than the button of his sleeves ; photography 
is mere mechanism, it is not art. 

To produce a good negative, say the photographers, 
on the other hand, it is necessary to study the subject as 
well as to select and combine the effects of light ; and 
this needs the intervention of artistic sentiment. The 
first negative obtained, says a distinguished practitioner 
of the art, the work is only sketched out. Light is an 
uncertain instrument which is never under complete con- 
trol. It is necessary that the photographer, appreciating 
its defects and its merits, should palliate the one and 
bring out the other more prominently. It is then, adds 
our apologist, that the photographer shows himself to be 
an artist in the full acceptation of the word ; that he 
causes his mind and his genius, if he have genius, to 
pass into the print ; that he gives it colour and that 
admirable completeness, as well as those effects which 
impress and take hold of the mind in as lively a manner 
when admiring certain photographic portraits or land- 
scapes as when in presence of a canvas of Ruysdael or 
of Titian. 

In a series of photographs, says an eminent scientific 
writer, we meet by turns a Van Dyk and a Delaroche, 
a Reynolds and a Turner, a Titian and a Scheffer, a 



PHOTOGRAPHY AND ART. 299 



Ruysdael and a Corot, a Claude Lorraine and a 
Marilhat. 

These views are evidently exaggerated on both 
sides. Let us try and give a just and reasonable opinion, 
avoiding the two rocks of systematic disparagement and 
of too enthusiastic admiration. 

Certainly photography has serious disadvantages. 
The instrument which acts has not the powers of the artis- 
tic hand, which is guided by the love of the beautiful and 
just impressions of the effects of nature. It often injures 
the linear as well as the aerial perspective ; the process of 
developing the image not unfrequently reproduces the 
distances as distinctly as the foregrounds ; while the 
shadows in some photographs form dark blots, flat and 
heavy tones, which deprive the picture of all grace and 
"harmony. Especially is this the case if the instrument 
is guided by an inexperienced hand. 

But it cannot be denied that the photographic ap- 
paratus, if managed by the hand of an operator having 
at the same time the skill of a proficient and the taste 
of the painter, produces pictures marked with the seal of 
art. 

We see every day issue from the studios of the 
masters of the art a great number of admirable photo- 
graphs : they have colour, relief, delicacy, and truth ; 



300 THE APPLICATIONS OF PHOTOGRAPHY 



some of them even can rival the most beautiful sepia 
drawings, or the finest miniatures. If, on the other hand, 
there are bad photographs, it must be admitted that 
some shocking bad pictures exist. 

We shall not enter further into this order of ideas 
and discussions. It is dangerous, in our opinion, to wish 
to establish a parallel between painting and photo- 
graphy, which differ essentially in their processes and 
mode of production. At the same time it appears to us 
to be exceedingly unjust to deny to photography the 
rank of one of the fine arts. 

It constitutes, doubtless, a true and a great art ; but 
we shall quit this slippe^ry ground for the purpose of 
broaching a much more interesting question, that of the 
services which photography is capable of rendering to 
all artists -to the painter, to the sculptor, to the archi- 
tect 

The illustrious Paul Delaroche, soon after the in- 
vention of the daguerreotype, did not fear to say, in pre- 
sence of the members of the Academy of Science, the 
daguerreotype carries to such perfection certain essential 
points of art that it must become an object of study 
and observation to the greatest painters. Paul Dela- 
roche spoke the truth. A collection of photographs is 
indeed an inexhaustible source of useful information for 



PHOTOGRAPHY AND ART. 301 



the artist. It is certain that no painter at this day, 
whatever may be his talent, will attempt to paint a por- 
trait without having good photographic likenesses of his 
sitter. It is also evident that a landscape painter cannot 
be too well acquainted with those admirable studies of 
nature which true artists have placed upon the collodion- 
ised glass. The student will also find valuable examples 
in those fine photographs which reproduce the magni- 
ficent cartoons of the Louvre — unique sketches, the 
produce of the magic crayon of Raphael, or the 
pencil of Michael Angelo. No one would be bold 
enough to attempt to reproduce the designs of these 
great masters by the burin of the engraver, or by the 
pen of the lithographer. Photography performs the 
miracle of multiplying to infin'ty an etching of Correggio 
or of Titian. 

Again, what resources in the hands of an architect, 
or an archaeologist, are the views of buildings in distant 
countries ! The marvels of Athens and of Rome, the 
inimitable richness of the monuments of India, the bold 
architecture of Egyptian temples, can be kept in his 
portfolio, not modified and disfigured by an untrust- 
worthy pencil, but such as they are in reality with their 
beauties, their imperfections, and the marks of destruc- 
tion which time has engraved upon them. Photographic 



302 THE APPLICATIONS OF PHOTOGRAPHY. 



prints are mirrors from which are reflected the banks of 
the Nile and of the Indus — the buildings and the land- 
scapes of all the countries through which the camera has 
passed. 

The explorer furnished with his photographic ap- 
paratus, which is now constructed in such a manner that 
it can be used with ease in any part of the world (fig. 74), 
brings back with him from his travels documents in- 
valuable, because no one can deny their accuracy. A 
photograph represents an object just as it is — the land- 
scape as nature has formed it — the building as it has 
been seen, a broken column, a mark upon a stone. No- 
thing is deficient in the print. A painting or a water- 
colour can never have such rigorous precision. The 
artist is often tempted to omit some object which appears 
to injure the efi"ect of the whole, or to add some orna- 
ment to his work. 

Finally, in certain cases, photography is able to repro- 
duce by the aid of artificial light the representation of 
masterpieces of art or of natural beauties which may be 
buried in darkness. In a great number of subterranean 
chambers, hollowed out under the ancient temples of 
Egypt, the walls are covered with paintings and hiero- 
glyphs which the savant cannot study with advantage 
during a short visit. The photographer, by means of the 
magnesium light, takes the exact transcript of these in- 



PHOTOGRAPHY AND ART. 



303 



scriptions, or of these figures ; he puts in the hands of the 
archaeologist a faithful copy on which he can study, by the 
aid of a magnifying glass, the most minute details. The 
mode of operating most frequently practised in Egypt is 



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fe> .-.. 






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a^^ 


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Sr? r>^^^^ 


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rHOTOGRAl'HY BY THE MAGNESIUM LIGHT IN THK CATACOMBS. 



identical with that employed in taking photographic views 
of certain curious parts of the catacombs of Paris% 
(Fig. 75.) 

The applications of photography to art are in- 
numerable, and the future will produce many results of 
the extent of which we cannot now give, an idea. 



304 THE APPLICATIONS OF PHOTOGRAPHY 



The carbon process of photographic printing, only 
recently discovered, will soon produce, if it has not 
already succeeded in producing, unchangeable prints as 
durable as the impressions of typography ; it will thus 
perpetuate in history the appearance of the great men who 
have played their part in the cjianges of modern society. 
What incomparable value would now be attached to 
photographs of the great writers of the age of Louis 
XIV., or of the philosophers of the eighteenth century! 
What profound emotion would not one feel in contem- 
plating the truthful images of the men of genius who 
have enlightened humanity ! 

Our descendants will assuredly enjoy such surprises 
and many more, which the most clear-sighted cannot 
foresee. 

All that we can affirm is, that if the uses of photo- 
graphy are now almost innumerable, they will certainly 
still go on increasing to an unknown extent. How- 
ever marvellous the results already obtained may be, 
they will be improved so as to reach such a summit of 
perfection as our mental eye cannot perceive through 
the dense mist which veils from us the image of 
the future. We have seen the efforts made by Becquerel 
and Niepce de Saint-Victor to obtain photographs with 
the colours of nature. The problem of coloured photo- 



PHOTOGRAPHY AND ART. 305 

graphy is not insoluble. It will be solved one day. 
Then the art will march along a new course wonderfully 
fruitful in such results. 

It is often imprudent, and even undesirable, to attempt 
to look too closely into the future, but in some cases it is 
possible to do so without exceeding too much the limits 
of reason. In such cases it is necessary to rest upon 
facts, and not give too much play to the imagination. 
We have studied the past of photography ; we have ad- 
mired the marvels we owe to it in the present ; will the 
reader pardon us if we now endeavour to dive a little 
into the future t 



306 THE APPLICATIONS OF PHOTOGRAPHY. 



CHAPTER XL 

THE FUTURE OF PHOTOGRAPHY. 

LAND-SURVEYING — THE ART OF WAR— WORKS OF ART— CRIMINALS 
AND JUDICIAL PHOTOGRAPHY- THE MIRACLES OF INSTANTANEOUS 
PHOTOGRAPHY. 

If we would fathom the depths of the future while re- 
straining ourselves at the same time within the limits of 
common sense, we must carefully examine the ground 
over which we would extend our view. We shall first 
examine what has been done up to this time in utilising 
photography in the art of taking plans, and then we 
shall be able to perceive the resources it will afford 
during war. 

A retired military surgeon, M. Auguste Chevalier, has 
already considered it possible to combine surveying with 
photography. He places a camera on a land-surveyor's 
stand, fixing it upon an axis so that it can be turned 
round in any direction. By directing the lens of the 
camera to the different points of the horizon pictures of 
each part are obtained, the whole forming a complete 



THE FUTURE OF PHOTOGRAPHY. 3O7 

panorama which must be absolutely correct ; from this a 
plan or map of the country can be drawn by means of 
certain operations, the details of which are too technical 
for us to enter into. 

In 1859, during the war in Italy, some military en- 
gineer officers, no doubt thinking of the polemoscope 
reflecting images by means of mirrors (fig. ^6), a kind of 
forerunner of the employment of the camera, made use 
of the photographic plate. The experiments they made 
allowed them to form some idea of the advantages of 
this new branch of photography, though they did not 
thoroughly master it. No doubt in the future, the 
camera will supply valuable assistance to the military art. 

The application of photography to taking military 
plans and panoramic views, in the opinion of competent 
judges, is on the eve of being completely realised. When 
this new application is perfected, science will again be 
distinguished by considerable progress. We cannot 
over-estimate the great services the camera ought to 
render in this kind of work. 

No longer any want of correctness in producing the 
plan, no minute calculation, no difficulty, no annoy- 
ance. The picture of the country will be taken, the map 
will be completed, without, so to say, giving it a thought. 
In time of war, a general will have photographs of the 



308 THE APPLICATIONS OF PHOTOGRAPHY. 

field of battle — of the fortresses he would besiege, and 
should any point of the horizon be concealed from him, 
the camera thrown into the car of a balloon held captive 
by a cord, and thus rising above woods and hills, will 
take a faithful impression of all within its view. 

Narrators of fairy tales and other extravagant stories 
have often put into the hands of their heroes magic mir- 
rors, wonderful talismans, which suddenly reflect the 
images of distant objects. Photography realises the con- 
ceptions of the imagination of the poet. We remember 
being present at a singular scene, which we shall en- 
deavour to describe. 

One of our friends, a military engineer, engaged in 
superintending some railway works, was addressing some 
words of blame to the contractor who was employed in 
building a bridge. He complained of certain faults of 
construction, and especially at the slow progress of the 
work. 

' But I beg your pardon,' replied the contractor. 
* Are you quite sure your information is correct, for you 
have not personally visited the works } ' 

' I have not stirred from home, it is true,' replied the 
engineer; 'but here is a mirror which is sent to me 
regularly, and which tells me every week what quantity 
of stones you have collected, what number of bars of 



THE FUTURE OF PHOTOGRAPHY. 309 



iron you have got together.' He then took from his 
drawer some photographs. 

* I employ a photographer,' he continued, ' who sends 
me every morning a picture of your work taken on 
the spot. Here is the complete series. The moving 
crane, which a fortnight ago was three yards from the 
second pile and which advanced five yards the preceding 
week, has moved very slowly for the last eight days. It 
is necessary, I tell you, to be more active. All that you 
do there, I see here ; the photographs which are sent to 
me give me even the appearance of your workmen, and 
if one of them has been idling while the picture was 
being taken, I can take him to task from my office here.' 

I listened to this singular conversation, and I said to 
myself, that the future would work out more perfectly 
this system already made use of The day may perhaps 
come when the negative will be taken at a distance by 
means of the electric wire ; and if some reader exclaims. 
Impossible ! I shall refer him to certain telegraphic sys- 
tems lately discovered, which allow us to anticipate this 
new miracle.^ 

Not less wonderful is the arrest of criminals by 

' I believe that there is nothing Utopian in the notion that, ere long, 
means will be discovered of telegraphing a photograph from one end of 
the earth to the other ; a most desirable consummation for the Metropolitan 
Police, and for the • Illustrated London News ' and * Graphic' — Ed. 



3IO THE APPLICATIONS OF PHOTOGRAPHY. 

means of their photographs. Here are some accounts of 
what has been. done in England, of a nature to show us 
the resources of judicial photography. 

It appears from a report on photographing criminals 
in London that from the 20th November 1871, to the 
31st December 1872, 375 arrests took place in England 
in consequence of the identity of criminals having been 
proved by means of their photographic portraits. Dur- 
ing this time there had been received from county and 
borough prisons at the Habitual Criminals Office 30,463 
portraits of criminals. This shows that the practice of 
taking the portraits of malefactors by means of photo- 
graphy is useful, and at the same time we may mention 
it does not cost much, since the portraits of all the pri- 
soners of the 1 1 5 prisons of England and Wales, from the 
time that the Act of 1870 came into operation to the 3 ist 
December 1873, only cost 2,948/. 18.$'. 3</. Perhaps it 
might be desired, in order to make the services it ren- 
ders more practical, that the criminal portrait gallery 
should be open to the public. It would thus be possible 
to make the arrest of malefactors, upon whom the police 
are unable to lay their hands, more easy. It would be 
the same with dead bodies which had not been claimed 
by anyone. We do not doubt that means would thus be 



THE FUTURE OF PHOTOGRAPHY. 311 

found for the arrest of murderers, whose names, as well 
as those of their victims, remain unknown. 

It is again from the foreigner, and this time from the 
United States, that we take some accounts, still more 
singular perhaps, of the uses to which the art of Daguerre 
may be put. 

An eye-witness from the other side of the Atlantic, 
who was present at some of the riotous scenes of the 
last elections, assured us that an American photo- 
grapher had succeeded in taking an instantaneous picture 
of a public meeting in the open air. He had suddenly 
fixed in the focus of the camera the orator who was 
gesticulating from the top of a temporary husting's, the 
group of listeners who were raising and waving their 
arms, some showing marks of approbation and approval, 
others with signs of impatience and anger. This photo- 
graph was immediately taken to his studio, for the 
purpose of converting the negative into a plate to be 
printed from by the heliographic process. If he had suc- 
ceeded, that very evening there might have been distri- 
buted 100,000 copies of the photograph, printed in an 
ordinary printing press. He failed, but others will 
accomplish this wonder of producing upon collodion 
such animated scenes, in depicting in a permanent 
form man in action, an agitated crowd, an army 



312 THE APPLICATIONS OF PHOTOGRAPHY. 

in battle, the orator as he speaks, the wave as it 
foams, or the meteor which traces its luminous track 
through the azure of heaven. 

We could still recount the resources which the art of 
the land-surveyor — geography, history, every branch of 
science as well as all the conceptions of human learning 
— will one day find in photography ; but the reader, after 
having acquired the knowledge of the actual powers of 
the wonderful invention of modern times which is the 
subject of this volume, will himself know how to look for 
the future applications which are logically derived from 
those actually practised. Instantaneous photography, 
the heliograph, photography naturally coloured by the 
light itself, will be the most fruitful branches of the tree 
planted by Niepce and Daguerre — their buds have 
scarcely yet burst from the stem, but they already 
appear, and no one can say to what heights they may 
reach. 



^*^ In the Appendix the reader will find some for mulcB of 
the various solutions 6^^. einployed in the Wet Plate and Dry Plate 
Processes and for obtaming paper proofs. Also some other matters 
of interest which it was difficult to give in the body of the work. 



313 



APPENDIX. 



PANORAMIC Ph TO GRAPHY. 

If a photographic camera is turned round upon its optical centre the 
image of an object will appear to move to one side on the ground glass. In 
reality the image remains stationary while the ground glass is in motion. 
Rotating cameras based on this principle have been constructed at various 
times. One of the best was that invented by Mr. Johnson, and called the 
Pantas5opic Camera ; but this instrument was only fitted with a single lens 
of short focus, so that the horizontal lines of the picture were always slightly 
curved. For large apparatus of this kind the clockwork by means of which 
the horizontal motion is obtained cannot be made cheaply and accurately, 
and at best it is easily deranged, and can only be repaired by a skilhil 
mechanician, and such would certainly not be found in regions where the 
finest scenery abounds. The large angle of view obtainable by the rotating 
camera, only limited by the length of the dark slide, rendered it desirable 
to introduce a simple instrument, not easily deranged, that could be adapted 
to any single, double, or triple lens, suitable alike for groups and landscapes, 
and capable of producing negatives equal to those taken with the best 
stationary cameras now in use. 

It appears that M. Liesegang, of Diisseldorf on the Rhine, has constructed 
a simple rotating camera which was employed by M. Schultz, of Dorpat, 
in taking the beautiful groups awarded a prize medal at last year's Paris 
Exhibition. The bridges and views taken by M. Schoenscheidt, of Cologne, 
as well as the work of many English, Italian, and Indian photographers, 
prove the success of the invention. M. Liesegang uses a stand nearly of 
the common tripod form, but stronger and more stable. This stand carries 
a large polished table supplied with a pivot or axis on which the camera 
turns. The pivot is so adjusted as to fall into the same plane as the optical 
centre of the lens. 



314 



APPENDIX. 



The camera is half as broad as it is high, and has a slit through which the 
rays of light pass which form the image, the opening of the slit being not more 
than a quarter of an inch wide, a little wider only where the near fore- 
ground falls, in order to secure a longer exposure for that portion of the 
picture, and thus impart greater uniformity to the tone of the negative. 
The dark slide when in the camera is closed around by a flexible band, the 
slit only being left open. 




PANORAMIC CAMERA. 



The two motions of the instrument, viz. that of the frame containing 
the prepared plate, from right to left, and the motion of the camera on its 
axis, are managed by a simple arrangement of horizontal cords and pulleys. 
The operator, after focussing, has only to turn a handle to take in the wide 
scope of the horizon, or a group of friends ranged in a semicircle round 
the instrument. The other operations are the same as in the ordinary 
camera. 



APPENDIX. 3 I 5 



THE HRLIOTYPE PROCESS. 

The Heliotype process, as worked by the Licensees of the Heliotype 
Company at their works at Kilburn, is based upon another method of 
utilising the action of light upon gelatine rendered sensitive by the admix- 
ture of bichromate of potash. It is in effect a development of the Albert- 
type process, wherein the gelatine itself forms no part of the picture, as in 
the Woodburj'-type, but is simply used as a printing surface. In the 
Heliotype process the gelatine is dissolved in warm water, and a sufficient 
quantity of bichromate of potash is added to make it sensitive to light, 
together with a certain proportion of chrome alum, to render it very hard 
and durable. This solution is poured, while hot, upon a glass plate pre- 
viously waxed ; the film, when dry, is stripped off, and exposed to light 
under a reversed negative. Having thus received the photographic image, 
the film is -made to adhere to a metal plate, the superfluous chemicals are 
soaked out in water, and the plate, bearing the printed surface of gelatine, 
is placed on an ordinary printing press, inked with lithographic ink, and 
the proofs are pulled, on either plain or enamelled paper, in the ordinary 
way, the plate being damped with water after each impression. The greasy 
ink readily adheres to the deep shadows, which, being hard, insoluble, and 
non-absorbent, have repelled the water altogether; the 'high lights,' on 
the contrary, having freely absorbed the water, repel the ink, and are left 
perfectly, white ; while the parts representing intermediate gradations of 
tone retain the ink in such degree as they have repelled the water. This 
graduated or discriminative power of absorption renders the mechanically- 
printed image a perfect transcript of the negative. The ink used may 
either be of a photographic tone, in which case the impressions when var- 
nished bear a close resemblance to silver-prints ; or it may be of any colour 
or tint desired, to ensure a close resemblance to any work of art that is 
being copied. Clean margins are obtained by the use of a * mask ' of thin 
paper, and thus the necessity of 'mounting' — so objectionable when the 
prints are to be used as book illus'^rations — is avoided. Surprise has often 
been expressed at the possibility of an organic substance such as gelatine 
being made to withstand the wear and tear of mechanical printing. But 
by the addition of chrome alum it is converted into a substance resembling 
horn, and as a matter of fact several thousand impressions have been 
obtained from a single film. The effect of an India or other coloured tint 
is obtained by using, instead of clear water for damping the plate, water 
with a small quantity of some dye in it. The Heliotype process, though 
for some purposes inferior to the Woodbury-type, offers special advantages 
for book-illustration, and has been adopted with success in many artistic 



3l6 APPENDIX. 



and scientific works of importance. One of the strong points of this 
process is the fidelity with which the character of the original is preserved, 
the appearance of 'glaze,' common to all silver prints on albumenised 
paper, and inevitable also in Woodbury-type prints, being entirely absent 
in the Heliotype. 



THE PHOTO-TINT PROCESS. 

This process, recently perfected by Mr. B. J. Edwards, is also in use at 
the same works as the above. It is more simple than the Heliotype, and 
while adding to the rapidity and certainty with which the prints are pro- 
duced, it gives finer and more delicate results. The frontispiece to this 
work is printed by the photo tint process. 



EPITOME OF THE WET COLLODION PROCESS AND 
USEFUL FORMULA. 

Negatives should be taken either on polished flat crown glass, free from 
specks and scratches, or on patent plate glass. It is false economy to 
employ glass of inferior quality, as what might at first appear only a 
trifling imperfection in the plate is apt to spoil the finest negative, or to 
cause breakage in the printing frame. 

The glass plate ought to be chemically clean ' when prepared to receive 
the collodion. It must indeed be borne in mind as a sort of maxim that 

' As it is often necessary to make use of old plates which it is a difficult matter to 
get perfectly clean, and unless they are clean a prolonged development of the image will 
often bring up stains on them, the following simple plan may be adopted : First, well 
wash the plates in water containing a very small quantity of muriatic acid ; rinse in plain 
water ; now coat the plates (which after drying must be carefully brushed wtih a badger- 
hair brush to remove any particles of dust) with a quantity sufficient to cover the plate 
of a mixture made as follows, and used fresh : — 

To 2 quarts of water add 7 drops of ammonia 
7 drops of acetic acid 
The white of one egg 
Well shake and filter. 

This mixture is used exactly as when coating the plate with collodion, except that any 
surplus is not returned to the bottle, but thrown away. The plates thus coated are dried 
in a drying rack away from dust, and when dry may be used at any time for receiving the 
collodion in the ordinary way. Plates thus prepared do not readily develop stains or 
show scratches, and are said to keep longer without drying in hot weather ; a great aid to 
the landscape photographer. 



APPENDIX. 317 



cleanliness of manipulation and methodical care are the chief attributes of 
the successful photographer. 

The plate is first coated with iodised collodion (see p. 109). Suitable nega- 
tive collodion and iodising solution may be procured in separate bottles, 
supplied with printed directions, from any photographic dealer. 



SENSITISnVG BATH. 



The nitrate of silver bath is next used for immersing the collodionised 
plate, and may be prepared in the following proportions : — 

Nitrate of Silver . . . . i ounce. 

Distilled Water . . . • ^5 ounces. 

Before using the bath (ioat a' plate with iodised collodion, and allow it 
to remain in the solution for four or five hours. After this plate has been 
withdrawn test the bath with a piece of blue litmus paper ; should the 
paper slowly change its colour to red, the solution may be filtered through 
blotting paper and used. But should' the test paper remain unaltered m 
colour, add one or two drops of nitric acid to the bath, so as to render the 
solution slightly acid before use. 



DARK ROOM OPERATIONS. 

When a collodionised plate has been immersed in the sensitising bath 
long enough to get quit of the greasy appearance on its surface, it may be 
removed, placed in the dark slide and exposed in the camera. The 
operator must use his own judgment in determining the duration of exposure. 
With a good portrait lens in a favourable light it will vary from one to ten 
seconds. The plate after exposure in the camera must be brought back to 
the dark room and developed. 

1st Developing solution: — 

Protosulphite of Iron ... 20 grains. 

Glacial Acetic Acid ... 20 minims (or drops). 

Alcohol 30 minims. 

Water i ounce. 



3l8 APPENDIX. 



Or, 

Ammonio-sulphite of Iron . . 20 grains. 

Glacial Acetic Acid . . . 20 minims. 

Alcohol 30 minims. 

Water I ounce. 

Either of the above solutions may be employed successfully by the 
beginner, but the proportions may be varied to such an extent as to enable 
almost every photographer to use his own favourite developer. 

When the first solution has been washed off, the re-developing or 
intensifying mixture may be applied in quantity sufficient to flood the 
plate : — 

Pyrogallic Acid .... 3 grains. 
Citric Acid ..... 3 grains. 
Water ...... i ounce. 

To this must be added, just before using, two or three drops of a 
solution of nitrate of silver: — 

Nitrate of Silver .... 30 grains. 
Water ...... 1 ounce. 

The action of the re-developer must be carefully watched by the light 
of the yellow window in the dark room, and arrested when the high lights 
of the picture have acquired the proper intensity. 



FIXING. 

Wash off the intensifier and consign the plate either to a bath containing 
a nearly saturated solution of hyposulphite of soda, or pour over its surface 
a weak solution of cyanide of potassium (100 grains to 10 ounces of water). 
In any case the negative, after it has been cleared of the yellow iodide of 
silver, must be thoroughly washed to remove all trace of the fixing agent. 
It is then dried and varnished. 

The negative varnish, which may be had from any photographic 
chemist, is applied in the same way as collodion, but the plate must be 
first slightly heated. The operator cannot go far wrong in following the 
printed directions on the bottle. 



APPENDIX. 319 



POSITIVE SILVER-PRINTING FORMULA. 

As the various operations connected with positive printing are described 
in these pages, it is needless to do more here than to supply useful formulae 
for ready reference. 

Sensitising bath for albumenised paper : — 

Nitrate of Silver .... 60 grains. 
Water i ounce. 

Toning solution : — 

Chloride of Gold .... I grain. 

Bicarbonate of Soda ... 4 grains. 

Water ...... 6 ounces. 

The toning solution may be used two or three minutes after it has been 
made. 

Fixing solution: — 

Hyposulphate of Soda ... 4 ounces. 
Water ...... i pint. 

The toned prints, after they have remained from fifteen to twenty 
minutes in the fixing solution, may be removed and thoroughly washed in 
repeated changes of water, and allowed to soak for twelve hours, when 
they may be dried, cut, and mounted. 

Sago, well boiled and strained through muslin, makes an excellent 
mounting paste. 



SIMPLE METHOD OF PREPARING DRY PLATES. 



By the kind perjuissicn of Canon Beechy and the Editor we are able to 
print the following interesting and useful extract from * The British 
Journal of Photography,' No. 804, Vol. XXII., October i, 1875. 



1. Always have in stock the following articles : — 

Absolute Ether 1 pint. 

Absolute Alcohol i ,, 

Alcohol 820 I ,, 

Hydrochloric Acid i ,, 

(Tlie latter is as useful in cleaning the plates for albumenising as for the emulsion.) 
Gun Cotton of suitable quality, at least . . i ounce. 

Bromide of Cadmium 1 ,. 

Pyrogallic Acid ....... 1 „ 

Fused Nitrate of Silver in powder , . . 1 „ 
The above constitute all the chemicals employed in the manufacture of these plates. 



320 APPENDIX. 



2. Have also in stoc'-, ready for use at any moment (a), at least two dozen properly 
albumenised plates, and {i) a stock bottle— say eight ounces — of the following bromide 
solution : — In eight ouncesof absolute alcohol dissolve five drachms of anhydrous bromide 
of cadmium. The solution will be milky. Let it stand at least twenty-four hours, or 
until perfectly clear. It will deposit a white powder. Decant it carefully into an eight- 
ounce vial, and add to it one drachm of strong hydrochloric acid. Label it 'bromide 
solution." It is as well to add on the label the constituents, which will now be found to be 
nearly — 

Alcohol .• I ounce. 

Bromide of Cadmium 32 grains. 

Hydrochloric Acid 8 drops. 

This solution will keep for ever, and be sufficient to last the amateur two or three years. 
With it at hand he is now able in two days to prepare a batch of plates at any time. In 
doing so he wi 1 proceed thus : — 

3 Settle how many plates you mean to make and take of the above accordingly. For 
two dozen half-plates (6^ x 4J) {a) dissolve by heat over (but not too near) a spirit lamp, 
and by a yellow light,', forty grains of nitrate of silver in one ounce of alcohol 820. 
Whilst this is dissolving in a little Florence flask, on a retort stand at a safe distance from 
the lamp (which it will do in about five minutes), take of the— 

ijj) Bromised Solution \ ounce. 

Absolute Ether i ,. 

Gun Cotton 12 ^jt\^ 

Put these into a clean bottle, shake once or twice, and the gim cotton, if good, will 
entirely dissolve. As soon as the silver is all dissolved, and whilst quite hot, pour out the 
above bromised collodion into a clean four-ounce measure, having ready in it a clean slip 
of glass. Pour into it the hot solution of nitrate of silver in a continuous stream, stirring 
rapidly all the while with the glass rod. The result will be a perfectly smooth emulsion 
without lumps or deposit, containing, with sufficient exactitude for all practical purposes, 
eight grains of bromide, sixteen grains of nitrate of silver, and two drops of hydrochloric 
acid per ounce. Put this into your stock emulsion bottle and keep it in a dark place at 
least twenty-four hours. When first put in it will be tuilky ; when taken out it will be 
creamy. It is well to shake it once or twice in the course of the twenty-four hours ; but 
do not always do so. 
4. At the end of twenty-four hours you can make your two dozen half-plates in little 
more than an hour. Proceed as follows : — Have two porcelain dishes large enough to hold 
six (or four, at least) of your plates. Into one put sufficient clean, filtered rain water to 
nearly fill it. Into the other put thirty ounces (a pint and a-half ) of clear, flat (not acid) 
table beer, in which you have dissolved thirty grains of pyrogallic acid. I rea ly do not 
know a simpler or more satisfactory preservative than the above. I like to use bitter 
beer at one shilling per gallon. The pyro. dissolves in it at once. Pour it through a 
filter into the dish, the neck of the funnel being within half-an-inch of the bottom, to avoid 
bubbles. If allowed to let stand an hour any beer will be flat enough. If the beer be at 
all brisk it will be difficult to avoid little bubbles on the plates. At all events, let your 
preservative stand whilst you filter your emu'sion. This must be done through cotton- 
wool into a perfectly clean collodion bottle. Give the emulsion a good shaking, and when 
all bubbles have subsided pour it into the funnel and it will all go through in five minutes. 
The filtered emulsion will be found to be a soft, smooth, creamy fluid, flowing easily 
and equally over the plates. Coat with it six plates in succession (if your dishes will hold 
six), and place each as you coat it in the water. By the time the sixth is in the first will 
be ready to come out. Take it out, see that all.greasiness is gone, and place it in the 
preservative. Coat another plate and put it in the water where the first came out. Remove 
your second plate from the water into th'e preservative, and in its place lay another freshly 
coated plate, and so on until the first six are all in the preservative and six more in the 
water. You now take the first plate out of the preservative into your drying-box, and 
again remove the first out of the water into the vacant place in the preservative. Coat 
another and put it into the vacant place in the water. Take your second plate out of the 
preservative into the drying-box and the second out of the w^er into the preservative, 

' If ordinary bromide be used, thirty-two grains of silver will be sufficient. 



APPENDIX. 32 



and so on till all your plates are through the process and locked up safely in the drying- 
box. By proceeding as above not a moment of time is lost, and yet each plate soaks 
sufficiently in the water and in the preservative. You will find an hour, if you are dex- 
terous, sufficient time for two dozen plates. 

As it is my wish to render this process so practical and simple that amateurs may 
make their own plates, the following particulars as to material, exposure, and development 
will not be de trap : — 

1. As to materials : I recommend all to be got from some eminent photographic che- 
mist. There are many such : in every large town at least one. I obtained my pyroxyline 
from Mr. Ronch, of Norfolk-street, who also made my dr>'ing-box from my instructions, 
than which nothing can work better. It holds twenty-four half-plates, has a sheet-iron 
bottom, with air-tubes supplying hot, fresh air between every two plates. I generally 
make my plates at night, and when they are all in the rack and locked up I light a spirit 
lamp containing one ounce of methylated spirit, under the drying-box, and go to bed. In 
the morning I may pack up my plates and set out on my expedition, confident that I have 
two dozen reliable dry plates. 

2. As to exposure : these plates do not profess to be zvry rapid, but they are sufli- 
ciently so for every ordinary purpose. From thirty to sixty seconds according to light will 
be enough, but they will do with less and bear strong ammonia development without 
fogging : or they will do with more, the development being stopped sooner. Unless you 
take with you the means of developing it is better to tiy a plate before j-ou start. In 
spite of every precaution there will somehow be a difference in a batch of plates now and 
then. I may mention, also, that I never back my plates, for the reason that I never 
find they require it. They will not blur with any light that will not also blur backed 
plates. 

3. For developing I use Colonel Wortley's strong developer. I mean the one published 
with his excellent rapid uranium plates, which I copy : — 

A. Pyrogallic Acid 96 grains. 

Alcohol I ounce. 

B. Bromide of Potash 12 grains. 

Water i ounce. 

C. Carbonate of Ammonia 64 grains. 

Hot Water i ounce. 

By all means use carbonate of ammonia. The liquid ammonia often destroys a good 
negative, and always gives a more inky picture. For a half-plate take of A thirtj' drops, 
of B sixty drops, of C two drachms, or even three if the exposure be short. I never use 
any alcohol, but simply wet the plate well under the tap, thereby washing off" the beer, 
and pour on the developer. The picture will come out in a few seconds. On its first 
appearance pour back the developer into the measure and let the picture come out of itself. 
You will be surprised to see how it 7£////come out. You can then judge as to exposure 
and proceed according'y, adding bromide if too rapid, or pouring on the developer as it 
was if all right, or with an extra thirty drops of C if under-exposed. These plates seldom 
require to be intensified. If they do the ordinary acid silver and pyro. redeveloper will 
bring them up easily and at once. Clear with either hypo, or cyanide as you please, and 
if you intensify do it after clearing ; but the beer gives these plates a bottle-green tint, 
which is more impervious to actinic light than from its transparency you wou'd suppose. 

These p'ates are more rapid if placed at once in the preservative without washing ; 
but they require to stay in till all greasiness has disappeared, and I doubt if they keep as 
well or are so certain. To wash first is safest for amateurs. 

In conclusion : I am glad you have asked me for the above formulae, since I have had 
more letters enquiring for them than I could find time to answer. I claim nothing new 
in the process but the beer and pyro. preservative. You know I am a pupil of Colonel 
Wort ley, and my process is essentially his applied to a humbler and more domestic class 
of plates. I have tried to simplify their preparation for amateurs, and I am quite sure 
ninety-nine out of a hundred will pre'er them to the host of complications which from 
time to time 'go up like a rocket and come down like a stick.' 



322 APPENDIX. 



WEIGHTS AND MEASURES, 

ENGLISH. 

Troy Weight. 
20 Grains = i Scruple. 9. 

3 Scruples = i Drachm. 3. 

8 Drachms = i Ounce. % 
12 Ounces = i Pound, lb. 

480*0 Grains Troy = i Oz. Troy. 

437*5 ,, ,, =1 Oz. Avoirdupois. 

yooo'O ,, ,, = I Pound ,, 

5760*0 ,, ,, =1 Pound Troy. 

I Minim (or drop) = I Minim. 

60 Minims = I Fluid Drachm, f 5. 

8 Fluid Drachms = i Fluid Oz. f 5. 

20 Fluid Ounces = i Pint, octarms. 

8 Pints =• I Gallon, congius. 

FRENCH. 

The French Kilogramme (= to about 2 lbs. 3 oz. 4^ drachpis Avoirdu 
pois) is the weight of a cubic decimetre of distilled water at the temperature 
of maximum density, 39° '2 Fahrenheit. 

One kilogramme = 10 hectogrammes = 100 decagi-ammes = 1,000 
grammes = 10,000 decigrammes = 100,000 centigrammes = 1,000,000 
milligrammes. 

(The French gramme = 15*4325 English grains.) 

The Kilolitre is a cubic decimetre. 

I kilolitre (^ 10 hectolitre @, 10 decalitre @ 10 litre @, 10 decilitre @ 
10 centilitre @ 10 millilitre. 

(The French litre = 1*76 Imperial pint, i.e. about 35 oz.) 

The Metre, the unit of the entire system of weights and measures 
known as the metrical system, is assumed to be the 0*000010 part of the 
quadrant, or the 0*000040 of the whole globe measured over the poles. 

I metre (= 3*2808 feet or about 39 inches) = 10 decimetres = 100 
centimetres = 1,000 millimetres. 

I metre = 0*1 decametre = O'Oi hectometre = 0*001 kilometre. 
I kilometre = 1093*633 yards. 

I Parisian foot = i *o658 English foot. 



INDEX. 



negatives, 



79 



ACC 

A CCIDENTS with 
-^ 141 

Albertype, t^e, 193 
Albumenised paper, 123 
Alchemists (the), 6 
Applications of photography, 
Arago, 55, 184 
Archer (Scott), 86 
Arrangements for lighting, 89 
Astronomical photography, 249 
Autotype Co., 147 

t) ALDUS, 161, 190 
■'-' Balm of Judaea, 35 
Barometrograph, 272 
Becquerel, M. E., 169 
Beechey's (Canon) dry plate process, 

319 

Bellows camera, 98 
Bichloride of mercury, 128 
Bisulphate of iron, 116 
Blanquart-Evrard, 64 
Bouton, 17 

r^AMARSAC'S process, 214 
Camera obscura, 2 



DAR 

Camera (simple), 97 

— (twin-lens), loi 

— stand, 99 
Cameras and lenses, 89 
Carbon print, 162 
Carrier-pigeon post, 235 
Catacombs, the, 303 
Celestial photography, 249 
Charles (Professor), 10 
Chevalier, 20 

Chinese tradition, 9 
Chloride of silver, 6 
Cleaning the plate, 105 
Clouds, methods of obtaining, 
Coating the plate, 109 
Collodion, 79, 86 
Coloured proofs, 143 
Cyanide of potassium, 1 1 7 

■pjAGUERRE, 14 

Dagiierreotype, 53 
Dark room, the, 2, 89 

— operations, 317 

— slide, 100 

— tent, 137 



i38 



Y 2 



234 



INDEX. 



DAV 

Davy (Sir H.). 12 

Degotti, 14 

Delaroche (Paul), 63 

Dc la Rue, 253 

Developer for negatives, 114, 317 

Developing agent, 5 1 

— of the picture, 105 
Development of image, 1 1 3 
Diorama (the), 17 
Dipping bath, 112 
Donne, M., 180 

Dry process, 154, 1 5 7, 319 

pARLY heliotypes, 180 

Electrograph, photo-, 277 
Enamelled Photographs, 214 
English weights and measures, 320 
Epitome of wet Collodion process, 

316 
Enlarging, 147 
Exposure in camera, 113 

pABRICI.US, 6 

Fixing of colours, 169 

— of the picture, 105 

— the negative, 1 17, 318 

— the print, 128, 318 
Fizeau, 180 
Focussing glass, 98 
Formic acid, 116 

French weights and measures, 320 
Future of photography, the, 306 

/^ALLIC acid, 161 

Gamier and Salmon, 192 
Gelatino-bromide process, 157 
Goupil, M., 200 
Greeks, the, 5 
Grubb, 253 
Gun cotton, 79, 85 



MIC 

"LTALL (Mr. Asaph), 260 
Harvard College, 259 
Flead rest, 103 
Heliography, 38, 179 
Heliotype process, the, 315 
Herschel (Sir John), 78, 80 
Hill, Mr., 171 
' Horn-silver,' 7 

Hyposulphite of soda, 67, 79, 117, 
318 

TMAGE, development of, 105 
— intensifying of, 105 

— fixing of, 105 

— varnishing of, 105 
Instantaneous photography, 140, 283 
Intensifying, 116, 318 

Intensity of light, 279 
Iodide of potassium, 133 
Is photography art? 297 

T ANDSCAPE photography, 93, 

^ 113 

Land surveying, 306 

Lasteyrie-Dussaillant (Count de), 30 

Legray, M., 161 

Lemercier, M., 189 

Lenses and cameras, 89 

Liebert's enlarging apparatus, 150 

Light, the influence of, 89 

Lithography, 30 

' Luna cornea,' 7 

TV/TADAME de Stael,»i46 

Magnetic needle, the, 276 
Magnesium light, the, 302 
Manipulation, 105 
Megascope, the, 148 
Meteorology, 269 
Microscopic despatches, 235 



INDEX. 



325 



Microscopic photography, 220 
Modern heliography, 195 
Monckhoven's enlarging camera, 149 
* Moniteur Universel ' (the), 54 
Monostereoscope, 287 
Mounting the print, 129 

TSJATIONAL reward, 61 
Negative (the), 105 

— characteristics of a good, 1 20 
Niepce (Isidore), 31 

— Joseph Nicephore, 25, 26 

— de Saint- Victor, 182 



/^BERNETTER'S process, 195 

Oil-coloured proofs, 143 
Orthoscopic lens, 136 
Out-door photography, 93, 135 
Over-exposure, effect of, 115 

pAINTED photographs, 143 
Panoramic photographs, 307, 

313' 

Panoramic photography, 313 
Pantascopic camera, 313 
Paper proof, 122 
Permanent carbon process, 167 
Pin holes in negative, 1 20 

— and spots, 141 
Phosphorus, 35 
Photocromos, 175 
Photo-electrograph, 277 
Photoglypty (or the Woodbury pro- 
cess), 199 

Photographic astronomy, 249 

— caricatures, 143 

— despatches, 235 

— enamels, 214 

— operations, &c., 89 



REG 

Photographic processes, 89 

— printing, 169 

— registering instruments, 2C9 
Photography and art, 297 

— in war, 306 

— and crime, 310 

— discovery of, i 
Photography, landscape, 94 

— on paper, 64 

— on glass, 79 
Photolithography, 187 
Photometry, 279 
Photomicrography, 220 
Photo-sculpture, 208 
Photo-tint process, 316 
Plate box, 119 

— cleaning of the, 105 

— coating with collodion, 105 

— exposure of in camera, 105 

— sensitising in bath, 105 
Poitevin, M., 174 

— Heliotype researches, 183 
Polemoscope, 307 
Political Photographs, 145 
Porta, J. B., 2 

Portable apparatus, 136 
Positive proof on paper, 122, 318 

— silver printing formulae, 3 1 8 
Pouncy, Mr., 163 

Practice of photography, 132 
Printing frame, 124, 126 

— from the negative, 124 
Problems to be solved, 169 
Processes, 153 

Properly timed exposure, 1 16 
Pyrelophore, the, 28 



"DACK for dr)'ing plates, 118 

Registering photographic in- 
struments, 268 



326 



INDEX. 



RET 

Retouching, 141 
Rolling the print, 129 
— press, 129 
Rotating Camera, 313 
Russell, Major C, 156 
Rutherford, 253 

C AINT-VICTOR (Niepce de) 7 

Salmon, Mr., 163, 192 
Salted paper, 123 
Scheele, 10 
Schoenbein, 85 
Secchi, 253 
Seebeck, 175 
Senefelder (Aloys), 30 
Sensitised paper, preparation of, 122 
Sensitising bath, 3 1 7 
Sensitising the plate, 105, 318 
Simple dry-plate process, 319 
Sitting or posing room, 89 
Smoked pictures, 42 
Solarisation, 137 

Stains and streaks in negative, 120 
Starch paste, 130 
Stereoscope, the, 287 
Stereoscopic vision, 287 
Studies of skies, 137 
Studio and apparatus, 89 
Sub-chloride of silver, 133 
Swan, Mr., 163 

n^ALBOT, 64, 75, 182 
Tannin process, 156 



woo 
Telegraphic photography, 309 
Terrace for printing, 89 
Theory of photography, 152 
Thermograph, 271 
Thermometer, registering, 271 
Thermometrograph, 275 
Toning the print, 127, 319 
Tourist Photographer, 135 
Transit of Venus, 260 
Twin-lens camera, loi 

T JNDER exposure, effect of, 115 

WAPOURS of mercury, 51 

Varnishing of the picture, 105 
Varnishing negative, 118 
View lenses, 135 
Vigier, M., 161 
Vignette glass, 125 
— pictures, 125 

Vignetting, simple method of, 125 
Vitrified photographs, 214 
Vitruvius, 6 
Voglander, M., 71 

V\7AR and Photography, 306 

Warren de la Rue, 251 
Watt (James), 12 
Waxed paper process, 159 
Wedgwood, 11, 12 
Willeme, M., 208 
Wheatstone's stereoscope, 287 
Woodbury, Mr., 199 



LONDON : I'KINTED BY 

3POTTISVVOODE AND CO., NEW-STUEET SQUAIiE 

AND PARLIAMENT STREET 



Advertisements, 



F. W. DEVOE & CO., 

Cor. of Fulton & William Sts., New York, 

ARTISTS' MATERIALS. 



Manufacturers A. 
Importers of 




(Factories, Horatio and Jane Streets, New York.) 

Manufacturers of Artists' Oil Colors, in Tutes; 

CAPAS, ACADEMY BOARDS, MILLBOARDS. AND OIL-SKETCHING PAPERS; 
FINE BRUSHES FOR OIL AND WATER COLOR PAINTING, 

VARNISHES, WATER COLOR LIQUIDS, OILS, Etc. 
Drawing Papers, Sketching Books and Blocks, Pencils, Mathematical Instru- 
ments, Charcoal and Crayon Drawing Materials, Illustrated Books on 
Art, Folding and Studio Easels. Drawing Boards, Studies, Manikins 
and Lay Figures, Out-of-Door Sketching Boxes. 

WINSOR & NEWTON'S CAKE AND MOIST WATER COLORS, 

Tube Colors, Canvas, Etc. ; also, French and German Goods. 
SCULPTORS' TOOLS, MODELING WAX AND CUY, PUSTER CASTS FOR MODELS, 

ANTIQUE POTTERY AND PORCELAIN TILES, 

With Materiils for Pottery and China Decoration. 
Fresco Designs and Colors, and Brushes for Fresco and Scenic Painting. 
Wax Flower Supplies — Colors, Tools, Moulds and Brushes. 
Manufacturers of White Lead, Zinc White, Colors and Varnishes. 



FRED'K W. DEVOE. 
JAMES F. DRUMMONP. 



FRED'K SAUNDERS, JR., 
J. BEAVER PAGE. 



A dvertisements. 



THOS. H. McCOLLIN, 
Photographic Chemist, 

634 Arcli Street, Philadelphia, - 

IMPORTER AND DEALER IN 

Foreign Photographic Spocialties. 

Refiner of PliotOErapMc Golfl & Silver Wastes. 

SOLE MANUFACTURER OF 

McCollin's Delicate Half-Tone Collodion, 

. McCOLLIN'S SILICATED CASTOR yARNISH. 

SOLE AGENT FOR 

American Collodion Pellicle Emulsion, 

MOKaiM'S AILBIUMEIIZE© PAPEKS 

AND 

LAMBERTYPE MATERIALS, 

And Licenses for Carbon iFork in the States of Pennsyl- 
vania, New Jersey and Delaware, <0c., <f c. 



SEND FOR CATALOGUE. 



Advertisements. 



BENERMAN & WILSON, 

116 lortli Seventh St., PMladelpMa. 



Centennial Views and Lantern Slides. 

THE PHILADELPHIA PHOTOGRAPHER, $5 per year. 
ROBINSON'S TRIMMERS AND GUIDES. 
WAYMOUTH'S VIGNETTE PAPERS. 
"SOMETHING NEW." 

THE MAGIC LANTERN, $1 per year. 
PHOTOGRAPHIC BOOKS. 

HERMAGIS' FRENCH LENSES. 

GIHON'S CUT-OUTS AND OPAQUE. 
"TO MY PATRONS." 

WILSON'S "LANTERN JOURNEYS," 12. 
MAGIC LANTERNS AND SLIDES. 



Of the latter AAre have the 

Largest Stock in A.merica. 



Advertise^nenis, 



J 



imm 



(Late with A. P. Hall,) 
1005 MAIN STREET 

(Opposite Grant House.) 



Wheeling, West Va. 



ALL GOODS USED IN THE 



Art of Photography, 

APPARATUS, CHEMICALS, 



FRAMES AND MOULDINGS. 



A FULL ASSORTMENT OF 



Papers, Mats, Picture Cord, Glass, &c., &c. 



PERSONAL ATTENTION GIVEN TO ALL OEDEfiS. 



Advertisements. 



NOW COMPLETE. 



ART JOURN AL. 

A volume of exquisite beauty, containing upward of Thirty Steel-plate 
Engravings. These alone would please the eye forever. 

As a periodical connected with Fine Arts it is unparalled on this Continent. 

It has a proud reputation, not only in America, but in England. 

The best artists and authors are employed in its production. 

The most skilled printers are engaged in its illustrations and letter-pres^* 

The Art Features of the Centennial Exhibition are well represented. 

It is the only journal that gives expression to the mind of the artist and 
art critic. 

As a book to place on a drawing-room table it is unequaled for its variety. 

It is indispensable to every one who desires to keep pace with the world 
of Art — whether in Painting, Sculpture, Architecture, Furniture, Household 
Decoration or Ceramics. 

No refined home ought to be without the Art Journ.\l. 

It is a perpetual feast for the mind, because it is associated with the beautiful 
Price, in Cloth, gilt edges, $13.00/ Half Morocco, gill edges, $15.00; Full Morocco, 

gilt edges, ^rS.oo. 

TO SUBSCRIBERS ONE DOLLAR LESS. 



What the press of Neiv York City say : 
" D. APPLETON & CO. 
*' Among the few publishers of works of unquestioned merit in this city, 
is D. Appleton & Co. In the multitudinous productions of this house it is 
wonderful to see how few there are not of value and worth. The buyer there, 
no matter how inexperienced, is sure to get the worth of his money. In 
speaking thus we refer, of course, to the exclusive publications of the house. 
Now, there is Appletons' Art yournal, for instance. In this country a more 
complete or finished book was never sent forth. In typography, in its artistic 
construction, it is more perfect than anything American ever seen before. Each 
number of this admirable periodical contains three steel engravings on heavy 
plate paper, from the rarest and most beautiful pictures in the world. These 
engravings are prepared regardless of expense. One recently produced cost 
no less than S700 in gold. In every respect it is an art journal, and no family 
of taste in the country should be without it." — From Commercial Advertiser, 
December 14, 1876. 



Subscriptions received by the publishers or their Agents. Agenciep: 22 Hawley st., Bos- 
ton; 922 Chestnut at., Philadelphia; 22 Post Office Avenue, Baltimore; 53 9th st., Pittsbarg; 
100 State St., Albany ; 42 State sn., Rochester ; 103 State st., Chicago ; 30 W. 4th st., Cincinnati ; 
805 Locust St., St. Louia; 20 St. Charles st.. New Orleans; 230 Sutter st., San Francisco. 

D. APPLETON A CO., Publishers. 

549 & 551 Bboadwat, New Yobk. 



Advertisements. 



t:h:e 



FIOfOIBlFIIG flMlS. 

A Monthly Journal devoted to Practical and 
Commercial Photography. 

It contains twenty-four pages of useful matter. 

Subscription price, $1 per annum, postage paid, including one 
copy Photographic Mosaics for 1876 as a premium. 

We give it to all readers of the Philadelphia Photographer, with 
which journal the Photographtc Times is bound each month, besides 
which, it has a long list of independent subscribers, thus making its 
circulation much larger than that of any photographic journal in the 
country. 

The advantages to advertisers are therefore apparent. 

We will accept a limited number of advertisements at the follow- 
ing rates : 

One page, one time $20 00 

^ ^'f page, one time 12 00 

Quarter page, one time 7 00 

Special terms for advertisements for a longer period. 

SOOVILL MANUFAOTUEING CO., Publishers, 

4:10 ^ 421 Broome Street, New York. 



Advertisements. 3 

John a. Hood. Wm. D. H. Wilson. 

^VSO^, HOOD & COMP^j^ 

^ Fo. 822 ARCH STREET, S 

PHILADELPHIA, 

MANUFACTURKRS AND IMPORTERS OF AND DEALERS IN 

Photographic Materials 

FRAMES, 

STEREOSCOPES, 

AND VIEWS. 



SOLE AGEN TS 



Ross AND Steinheil Lenses 



Orders solicited. 

Price Lists gratis to all applicants. 

TRADE AGENTS FOR THE PUBLICATIONS OF THE 

CENTENNIAL PHOTOGRAPHIC COMPANY. 



A dvertisements. 



tttwod's pniic Jtlti'lial. 



C. H. GRAVES & SONS 



35 HAVS^KINS STREET, 

S@8ir©H, SASS. 



The above brand of Alcohol is distilled with great care, 
and is pecjdiarly adapted^ to the wants of the Photo- 
graphic trade. Stoch dealers may be interested, to hnow 
that all our Alcohol is drawn from a sealed measure, 
and we warrant casks to hold just what we bill them. 

Barrel Orders may be addressed to the manufac- 
turers. 

At retoAl by every live and reliable Stoch House in 
the United States. 



Adveriisemenis. 



Lewis Pattberg & Bros. 

MANUFACTURERS OF FINE 

VELVET FRAM ES, 

"GILT OR NICKEL," 
FOR TRANSPARENT PICTURES; 

passe paifteittst 
E isT C3- Xj I s h: 3Nwd:^a?s, 



AND ALL KINDS OF 



FANCY BRASS WORK. 



FACTORY: 

Jersey City Heights, N. J. 

WAREROOM AND OFFICE: 

IN'o. 709 Broadway, ItsT. Y. 



Advertisements. 



184=3 




1877 



"THE OLD HELIABLE' 



x)e:fot, 

ES TA BUSHED THIR T Y-FO UR YEARS, 



FOR THE SALE OF 



-Photographic Stock, Chemicals 

TUBES AND APPARATUS, 

P. SMITH & CO., 

No. 121 West Fifth Street, 
CINCINNATI, OHIO. 



A dvertise merits. 



zkmwL FECI I so. ' 

WERE AWARDED THE 

MEDAL OF MERIT 



FOR THEIR 



Union Picture Nails and Knobs, 

Grapho-Stereoscopes, 

UNION FRAMES, 

FbotograpMc FriiatiEg Frames^ 

NEGATIVE BOXES, &c.', 

AT THE 

ileal Oiitiulil lip©iitl@i$ 

1876. 



SCOVILL MANUFAOTUEING CO., Agents, 

419 & 421 Broome Street, 
NEW YORK. 



Advertisements, 



TRAPP & MUNCH'S 




THE PAPER OF THE DAY. 

Introduced in this country since 1868, it has become the leading 
paper, and is now better known and more appreciated than any other 
brand. 

That this great success is well deserved, and that this paper is 
superior to all others, may be judged from the fact that of all of the 
competitors of the Vienna Exhibition, Messrs. Trapp & Munch 
alone received the 

for Albumenized Paper, and also received the only 

Medal and Diploma at the Centennial Exhibition 

at Philadelphia, granted to any foreign exhibitors of albumenized 
paper. 

WILLY WALLACH, 

General Agent for the United States, 

NO. 4 BEEKMAN STEEET AND 36 PARK ROW, 

New Yorlc 



Advertisements. 



ESTABLISHED 1S60. 



HENRY D. MARKS, 

DEALER IN 

PHOTOGRAPHIC GOODS, 

Over No. 12 State Street, 



My Stock includes Apparatus, Chemicals, Glass, Plates, 
Paper, Card Stock, Stereoscopes, and a large and desirable 
assortment of Frames, Mats, and Passe Partouts. 



I make a specialty of 

SILK VELVET PASSE PARTOUTS, 

and can show the best variety of these goods to be found 
anywhere. 

Headquarters for everything pertaining to Photography. 

Best Goods, Lowest Prices, and over twenty-five years^ 
experience. 



Advertisements. 





Ho 

^ < 

w 



O 

z 

Q 
O 

o 
w 
w 
Pi 



REMINGTON'S 

Breech-Loading Rifles. 

LONG-RANGE. 

" Creedioor," (as used by tie Rile Teams.) 

No. 1 —Pistol-grip-stock, vernier and wind-guage _j^«e 
sights, 34 inch barrel, 10 lbs. weight , .$100 00 

No. 2—' i)oriing—P—G— pattern— 8tock, vernier and 

Wind-gauge sights, 34 inch barrel, 10 lbs. v?eight. . . 75 00 

No. 3— Militaiy — Stock, vernier and -wind-gauge 

sights, 34 inch barrel, 10 lbs. weight 55 00 

Extra — 8ame as No. 1, except rubber butt and tip, and 
checked for- end, including spirit level and 2 ex. 
disc 125 to 

Superior— Hame as extra, except selected curley pol- 
ished stock 150 00 

MID-RANGE. "Wimbledon." 

44-77, 45-70 and :;o-70. '-^ '"• =*» '"• 
No. O— Sporting stock, ordinary peep and globe 

sights $39 00 $41 00 

No. 1— Sporting stock, improv'd peep and globe 

sights 44 50 46 50 

No. 2— Si)orting P G pattern stock, improved 

I)eep and globe sights 50 00 52 00 

No. 8— Sporting P G pattern stock, improved 

peep and wind-guage sights 51 50 53 50 

No. 4— Sportmg P G pattern stock, vernier peep 

and wind-gauge sights 60 50 62 50 

No, S— Sporting pistol-grip stock, vemifer i)eep 

and wind-gauge sights 64 00 66 00 

No. 6— Sporting pistol-grip fine stock, rubber 

butt and tip, checked tor-end, vernier i)eep 

and wind-guage sights 75 00 77 00 

SHORT-RANGE. '• Dollymount." 

40-50, 40-70 C F ; 46, 44, 38, R. F. •■^«i°- '-^'p- 

No. O— Siwrting stock, ordinary peep and globe 

sights $87 00 $39 00 

No 1— Sporting stock, improved peep and globe 

sights 42 50 44 60 

No 2— Sporting P G pattern stock, improved 

I)eep and globe sights 50 00 52 00 

No. 3— Pistol-grip stock, improved peep and 

globe sights 54 00 56 60 

No, 4— Pistol-grip stock, vernier peep and wind- 
gauge sights 62 00 64 00 

SPORTING-38, 44, 46 Rim-fire ; 40, 44, 45 and 50 Cen • 

ter-fire 26 inch, $32, 28 in., $34, 30 in., $36, 32 in., 38 00 

GALLERV— 22,32, 38 Rim-fire $34 and 32 00 

38 Rim-fire, special 20 00 

MILITARY-U. S. model and Span- 
ish model $j6 50 $18 50 with bayonet 

MILITARY— Springfield model. 13 00 15 00 " 

" Egyptian model... 17 00 20 50 with sabre. 

Civil Guard 17 00 20 60 

" Carbine 16 00 

Send for illustrated catalc^rue. Address, 

E. REMINGTON & SONS, 

P. O. Box 3994. 283 BROADWAY. 

Armory, Ilion, N. Y. New York. 



Advertisements. 11 



STANDARD WORKS ON CHEMICAL ANALYSIS, 

PUBLISHED BY 

D. VAN NOSTEAND, 23 Murray and 27 Warren Streets. 

Beilstein. An Introduction to Qualitative Chemical Analysis. By F. 
Heilstein. Translated from the Third German Edition by I. J. 
Osbun. i2mo, cloth $o 75 

Crookes. Select Methods in Chemical Analysis (chiefly Inorganic). 

, By Wni. Crookes, F.R.S. Crown, 8vo, cloth 625 

^Douglass &. Prescott. Qualitative Chemical Analysis. A Guide 
in the Practical Study of Chemistry, and in the Work of Analysis. 
By Prof. S. H. Douglass and A. B. Prescott, of the University of 
Michigan. 2d Edition, revised, Svo, cloth 3 50 

Eliot & Storer. A Compendious Manual of Qualitative and Quanti- 
tative Chemical Analysis. By Prof. Charles W. Eliot and Prof. 
Frank H. Storer. Revised, with co-operation of the authors, by 
Wm. Ripley Nichols. Fourth Revised Edition. i2mo, cloth i 00 

Fresenius. Qualitative Chemical Analysis. By Dr. C. R. Fresenius, 

8th English from the 13th German Edition, by A. Vacher. Svo, cloth. 600 

Fresenius. Quantitative Chemical Analysis. By Dr. C. R. Fresen- 
ius. 7th English Edition. Vol. i. Svo, cloth 750 

Mott. The Chemist's Manual. A Practical Treatise on Chemjstry, 
including Qualitative and Quantitative Analysis, etc., etc. By Dr. 
Henry A. Mott, Jr. Svo, cloth \ 6 00 

Naquet. Legal Chemistry. A Guide to the Detection of Poisons, 
Examination of Stains, etc., as applied to Chemical Jurisprudence. 
Translated, with Additions from the French of A. Naquet, by Dr. 
I. P. Buttershall, and a Preface by Dr. C. F. Chandler. i2mo, cloth 2 00 

Plattner. Manual of Qualitative and Quantitative Analysis with the 
Blow-Pipe. From the last German "edition, revised and enlarged, 
by Prof. Th. Richter. Translated by Prof. H. B. Cornwall and 
John H. Caswell, A.M.. Svo, cloth. . . .' 5 00 

Plympton. A System of Instruction in the Practical Use ol the Blow 
Pipe. Being a Graduated Course of Analysis for the Use of Students, 
and all those engaged in the Examination of Salts and Minerals. 
Compiled and arranged by Prof. George W Plympton. i2mo, limp cl. i 50 

Prescott. Outlines of Proximate Organic Anal}^sis for the Identifica- 
tion, Separation and Quantitative Determination of the more com- 
monly occurring Organic Compounds. By Prof. A. B. Prescott. 
i2mo, cloth I 75 

Prescott. Chemical Examinations of Alcoholic Liquors. A Manual 
of the Constituents of the Distilled Spirits and Fermented Liquors 
of Commerce, and their Qualitative and Quantitative Determina- 
tions. i2mo, cloth I 50 

Rammelsburg. Guide to a Course of Quantitative Chemical Analysis, 
especially of Minerals and Furnace Products. Illustrated by Exam- 
ples. By Dr.C.F.Rammelsburg. Translated by I.Fowler,M.D. Svo, cl. 2 25 

Wanklyn.' Milk Analysis : A Practical Treatise on the Examination of 
Milk and its Derivatives — Cream, Butter and Cheese — by J. A. 
Wanklyn. i2mo, cloth. New York, 1874 100 

Water Analysis. 4th Edition, i2mo, cloth. London, 1876 2 50 

Tea, Coffee'and Cocoa : A Practical Treatise on the Analysis of Tea, 

Coffee and Chocolate. i2mo, cloth. London, 1874 2 50 



12 Advertisements. 



CHARLES COOPER & CO. 

OFFER AT WHOLESALE: 

PHOTO. CHEMICALS, 

STRICTLY PURE AND OF FULL WEIGHT; 

CROSS SWORDS DRESDEN 

eilUIll lT4Ftl. lliSlS, 

'SOLID GLASS BATHS, 



ETC 



We are the largest and most reliable house for Refining 
Photographic Residues. 

CHARLES COOPER & CO., 

MANUFACTURING CHEMISTS AND IMPORTERS, 

191 "Worth Street, 

NEW YORK. 



Advertisements. 13 



J. C. SOMERVILLE, 

No. 8 South Fifth Street, 



DEALER IN 



Photographic Materials 

OF EVERY DESCRIPTION, 

FRAMES, MATS, PICTURE CORD, 
Albums, Glass, &c. 

ST- XjOXJIS, ISJSiO. 



Tilford's Iodized Collodion, 

Tilford's Negative Collodion, 

Tilford's Silver Bath Solution, 
American Optical Co.'s Celebrated 

Camera Boxes and Apparatus, 

Powers & VVeightman's Silver, 

Gold, Iodides and Bromides, 
Voightlander & Sons' Lenses, 

Oval and Solid Oval (jOld Frames, 

Oval and Square Solid Walnut Frames, 
Oval and Square Imitation Frames, 

Glass and Ferro Plates, 

Screw Eyes, Backing, 

AND EVERY WANT FOR THE TRADE. 



14 Advertisements. 



THE SCIENTIFIC AMERICAN REFERENCE BOOK, 

Price, Twenty-five Cents. 

This is a most useful little bound book of 150 pages, comprising, proba- 
bly, the most extensive variety of standard, practical, condensed information 
ever furnished to the public for so small a price. Contents : 

1. The Last Census of the United States (1870), by States, Territories 
and Counties, in full, showing also the area in square miles of each State 
and Territory. 

2. Table 6f Occupations. — Showing the occupations of the people of the 
United States, and the number of persons engaged in each occupation. 
Compiled from the last census. 

3. Table of Cities having over 10,000 inhabitants. Compiled from the last 
Census. 

4. Map of the United States. Minature outline. 

5. The United States Patent Laws (full text).— Principal Official Rules 
for Procedure ; Directions How to obtain Patents ; Costs, etc. ; Forms for 
Patents and Caveats ; How to Introduce and Sell Inventions ; Forms for 
Assignments ; Licenses; State, Town, County, and Shop Rights ; General 
Principles applicable to Infringements; Synopsis of the Patent Laws of 
Foreign Countries ; Rights of Employers and Employees in respect to In- 
ventions. 

6. The Ornamental Design Patent Law (full text). — Costs and Procedure 
for securing Design Patents for Ornamental Productions such as Designs 
for Textile Fabrics, Patterns for Wood and Metal Work, New Shapes and 
Configurations of any article of Manufacture, Print?, Pictures and Orna- 
ments, to be printed, woven, stamped, cast, or otherwise applied upon 
machinery, tools, goods, fabrics, manufactures. 

7. The United States Trade-Mark Law (full text).— With Directions, 
Proceedings and Expenses for the Registration of Trade Marks of every 
description. 

8. The Label Copyright Law (full text).— With Directions, Proceedings 
and Cost of Registering Labels for Goods, Medicines and Merchandise of 
all kinds. 

9. The General Copyright Law of the United States (full text).— With 
Directions and Costs for Securing Copyrights by Authors for Books, 
Pamphlets, Charts, Photographs, Pictures and Works of Art. 

10. The Principal Mechanical Movements. — Described and illustrated by 
150 small diagrams, of great value to Inventors and Designers of Mechan- 
ism, 

11. The Steam Engine. — With engraving, showing all the parts, names, 
etc, and a brief history of the Invention and Progress of Steam Power, 



Advertisements. 15 



12. Geometry, as Applied to Practical Purposes. With illustrations. 

13. Horse Power. — Simple Rules for Calculating the Horse Power of Steam 
Engines and Streams of Water. 

14. Knots. — Presenting engravings of 4S different kinds of Rope Knots, 
with explanations as to tying. 

15. Tables of Weights and Measures. — Troy, Apothecaries', Avoirdupois, 
French Weights ; U. S. Standard; Dry Measure; Land Measure; Cubic 
Measure ; Liquid Measure ; French Square Measure ; French Cubic, or 
Solid Measure ; Measuring Land by Weight ; Engraving of a section of 
English and French rule, of equal length. 

16. Valuable Tables : (i) Velocity and Force of the Wind. (2) Specific 
Gravity and Weight per Cubic foot and Cubic inch, of the princip'al sub- 
stances used in the Arts. (3) Heat conducting Power of various Metals 
and other Solids and Liquids (4) Table of the Mineral Constituents ab- 
sorbed or removed from the Soil, per acre, by different crops. (5) Table 
of Steam Pressures and Temperatures. (6) Table of the Effects of Heat 
upon various bodies, melting-points, etc. 

17. Medallion Portraits of Distinguished American Inventors, with bio- 
graphy in brief, and engravings of their inventions, viz. : Franklin, Fulton, 
Whitney, Wood, McCormick, Blanchard, Winans, Morse, Goodyear, Howe, 
Lyle, Eads. 

18. Engravings of Capitol, Washington, with brief history, dimensions, 
cost, etc. ; United States Patent Office, interior and exterior views, dimen- 
sions and description ; Scientific American Buildings, New York and 
Washington. 

19. Miscellaneous Information. — Force of Expansion by Heat; Small 
Steamboats, proper dimensions of Engines, Boilers, Propellers, Boats ; 
Incubation, Temperature of; To Make Tracing Paper; Constituents of 
various substances; Friction, how produced, and Rules for Calculation ; 
Specific Heat Explained ; Specific Gravity of Liquids, Solids, Air and 
Gases; Gunpowder — Pressure, Heat and Horse-Power of; Copying Ink, 
to Make ; Heat, its mechanical equivalent explained ; Molecules of Mat- 
ter, size and motion explained ; Lightning and Lightning Rods — valuable 
information ; Value of Drainage Explained ; Amount of Power at pre- 
sent yielded from Coal by best Engines ; Sound — its velocity and action ; 
Liquid Glues, Recipes ; Value of Brains ; Properties of Charcoal ; Height 
of Waves ; Speed of Electric Spark, etc. ; Plain Directions, with Engrav- 
ings, showing how any person can make Electro Magnets and Electric 
Batteries a^a cost of a few cents ; Valuable Recipes. 

The Scientific American Reference Book, price only 25 cents, may be had of 
News Agents in all parts of the countrj-, and of the undersigned. Sent by 
mail on receipt of the price. Address 

iv^xjiisrisr <sc co., 

37 Park Row, New York, 



16 



Advertisements. 



MAMMOTH 



stocik: hiotjse. 




EIOE & THOMPSON, 

Manufacturers 

AND 

WHOLESALE DEALERS 

IN 

Photographic 

Materials, 

MOULDINGS, 
Frames, Mirrors, Pictures, 

GLASS, 

CORDS,TASSELS,CHROMOS, 

Mirror Plates, Albums, Fancy Goods, Etc., 

CHICAGO, ILL. 



Advertisements. 1 7 



t]h:e 



American Optical Company 

Manufactures the Most Perfect 

PHOTOGRAPHIC APPARATUS 

YET INTRODUCED TO THE PROFESSION IN EURORE OR 

AMERICA. 

THIS FACT IS UNIVERSALLY CONCEDED. 

THEIR APPARATUS 

RECEIVED 

THE HIGHEST AWARD 

AT THE 

Vienna Exposition,- - 1873, 
Brussels " - 1874, 

Centennial " - 1876, 

UPON WHI^II OCCASIONS IT WAS PLACED IN' COM- 
PETITION WITH THE BEST APPARATUSES 
FROM THE BEST MAKERS OF 

ENaLAlB. GEMMAMY, FMAICE k AfflEMICA. 



For Sale by all Dealers in Photographic Stock throughout Europe and the 
United States and Oanadas, 



18 



Advertisements. 



THE AMERICAN OPTICAL CO.>S 

IMPROVED VIEW CAMERAS, 



WITH CONE BELLOWS, 




are models of lightness, strength, compactness and durability. 



THEIR 



POCKET CAMERAS 




are the simplest, most compact and portable apparatuses ever made. 



Advertisements. Id 1 



FRED. MULLETT, 

(Successor to G. D. Wakely,) 
DEALER IN 

PHOTOGRAPHIC MATERIALS, 
Frames, Glass, Picture Cord, Etc., 

518 AVALNUT STREET, 

KANSAS CITY, MO. 



THE Gr-RV^ATV 

National Photographic Emporium 

46 NORTH CHARLES STREET, 
Baltimore, Md. 

The most complete and best regulated Stock house in America. 

EVEKYTHING PERTAINING TO PHOTOGRAPHY 

at the lowest market rates. 



Send for a copy of 

THE PHOTOGRAPHER'S FRIEND, 

Fiftli Edition. 

R. WALZL. 

Sent gratis upon application. 



30 Advertisement. 



CENTENiriAL 
PHOTOaRAPHIC COMPAIIY, 

International Exhibition G-ronnds. 
BELMONT AVENUE, 

View^ of \k\^ der\teni\ikl 5<xl:\ibitioi\, 
EXTERIORS AND INTERIORS, 

FOR THE 

Graphoseope, Stereoscope, 

PORTFOLIO, 
Magic Lantern and Card Holder, 

PROPRIETORS. 

ALSO A COMPLETE ASSORTMENT OF 
JStEREOSCOPES, pRAPHOSCOPES, txC. 

KILBUEN'S WHITE MOUNTAIN STEEEO-PIOTUEES, 

AND OTHER AMERICAN VIEWS. 



Advertisements. 



21 



MANUFACTURER OF 





JVo. 182 cjsjvtSI:e st^ejet, 

(UP STAIRS,) 



Corner Hester Street, 



NEW YORK. 



"V7". F. j^SHE, 



And manufacturer of 



Photographic Backgrounds, 

INTERIOR, LANDSCAPE, PLAIN, REMBRANDT, 
AND SHADED. 

SLIPS AND ACCESSORIES OF ALL KINDS 
Blue FrostiMg tor SkyligMs, etc. 

SertcL for Samples cltxcL ^rtce Ltst. 



OFFICE AND SHOW ROOMS: 

No. 106 Bleecker Street, corner of Greene, 

NEW YORK. 



22 V Advertisements. 



ESTABLISHED 1S03. 



S O O ^IL L 

Manufacturing Company, 

MANUFACTURERS OF AND DEALERS IN 

PHOTOGRAPHIC GOODS 

OF EVERY DESCRIPTION. 



STOCK DEALERS, PHOTOGEAPHERS 

AND 

SUPPLIED. 



MANUFACTORIES; 

Waterbury, Ct. ; New Haven, Ct. ; New York. 



WAREHOUSE: 

419 and 431 Broome Street, 



Advertisements. 23 

THE "PEERLESS" 

IS THE BEST AND THE CHEAPEST 

PORTRAIT LENS 

Il:T XJSE. 

Highest Testimonials from the best Photographers 
in the Country. 

EVERY LENS WARRANTED-SATISFACTION GUARANTEED. 



MORRISON^S 

Wide Angle View Lenses. 

(PATENTED MAY 21st, 1872.) 

Thdj ernhrace an angle of fully 100 degrees, work 
more rapidly than any other Wide Angle Lens made, and 
are absolutely rectilinear. 



MORRISON'S 

NEW RAPID COPYING LENS, 

FOR 

COPYINa OUTDOOR GROUPS AND INSTANTANEOUS VIEWS. 

These JJenses work with full aperture for Groups, and 
will copy with absolute correctness Architectural Drawings^ 
Charts, Engravings, §-c., ^c. 

FOE SALE BY ALL DEALEES. 




Advertisements. 



0«^p Afe|I 




For ExMDiting 
Plotograpiic Portraits, 
Landscapes, and otler 
Pictorial Works of Art, 
eitner Single or Stereo- 
scopic Views. 

Tnese Instruments are 
fnrnisnedwitn tie finest 
Imporied Lenses, and are 
snperior in pality and 
Material to tliose dl 
any otlier make in tie 
market. 



Nos. 0, 1 and 2 are made of Black "Walnut and finished in Oil.— Nos. 2i, 3 and 4 are made 
of Black Walnut, are heavier than Nos. 0, 1 and 2, and are handsomely polished.— No. 5 is made 
partly of solid Rosewood and is partly veneered in Rosewood. The box is lined with Curled 
Maple, and the whole polished.— No. 6, Black Walnut, polished, eleg:intly trimmed and fin- 
ished.— No. 7 is made like No. 5, except that it has a four inch lens, and is exquisitely finished 
in French polish.— No. 8 is made ot solid Walnut, finished and trimmed like No. 9.— No. 9, ele- 
gantly made of solid Rosewood, superbly finished in French polish and richly trimmed in bur- 
nished nickel. The Grapho. lens slides vertically on polished nickel rods, capped with ivory. 
The picture rest is of exquisite open work design, and is supplied with ground-glass for transpa- 
rent stereoscopic pictures. 




SCOVILL MANUFACTURING- COMPANT, 
419 & 421 Broome St., New York. 



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