The History and Practice of the Art of Photography

Snelling

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PRACTICE OF THE DAGUERREAN AND PHOTOGENIC ART, BOTH ON METALIC,

PLATES AND ON PAPER.

By HENRY H. SNELLING.

ILLUSTRATED WITH WOOD CUTS.

Entered according to act of Congress in the year 1849, by H. H. Snelling,

TO EDWARD ANTHONY, ESQ., AN ESTEEMED FRIEND.

Whose gentlemanly deportment, liberal feelings, and strict integrity

have secured him a large circle of friends, this work is Respectfully

Dedicated By the AUTHOR.

PREFACE.

would be devoted to the subject, but the wants of the numerous,

and constantly increasing, class, just mentioned, induces him

to wait no longer.

All the English works on the subject--particularly on the practical

application, of Photogenic drawing--are deficient in many minute details,

which are essential to a complete understanding of the art.

Many of their methods of operating are entirely different from,

and much inferior to, those practised in the United States:

their apparatus, also, cannot compare with ours for completeness,

utility or simplicity.

I shall, therefore, confine myself principally--so far as Photogenic

drawing upon metalic plates is concerned--to the methods

drawing upon French and English authority only in cases

persons from embracing the profession.

To English authors I am principally indebted for that portion

of my work relating to Photogenic drawing on paper.

branch of the art. Besides, it has been but seldom attempted

in the United States, and then without any decided success.

Of these attempts I shall speak further in the Historical

portion of this volume.

Every thing essential, therefore, to a complete knowledge of the whole art,

comprising all the most recent discoveries and improvements down to the day

of publication will be found herein laid down.

New York, January 27, 1849.

E. ANTHONY, ESQ.

of Photography to your perusal, and for your approbation, I do

so with the utmost confidence in your ability as a practical man,

knowledge of the sciences generally; as well as your regard for candor.

To you, therefore, I leave the decision whether or no I have

to dedicate it to you, subscribing myself,

With esteem,

Ever truly yours,

HENRY H. SNELLING

New York, February 1st, 1849.

Mr. H. H. SNELLING.

Dear Sir--Your note of January 27th, requesting permission

to dedicate to me your "History and Practice of Photography,"

I esteem a high compliment, particularly since I have read

the manuscript of your work.

the subject will make the book as interesting to the reading public as it

There is much in it to arouse the reflective and inventive

along with very little knowledge of the true theory of their art,

and yet the quality of their productions is far in advance

establishments I have had the pleasure of visiting I feel therefore,

that when a sufficient amount of theoretic knowledge shall have

been added to this practical skill on the part of our operators,

and when they shall have been made fully acquainted with what has

in the art will be manifested.

A GOOD Daguerreotypist is by no means a mere machine following

It is because they look upon their business as a mere mechanical

operation, and having no aim or pride beyond the earning of their

daily bread, they calculate what will be a fair per centage

on the cost of their plate, case, and chemicals, leaving MIND,

which is as much CAPITAL as anything else (where it is exercised,)

entirely out of the question.

The art of taking photographs on PAPER, of which your work

treats at considerable length, has as yet attracted but little

to attain an importance far superior to that to which the

Daguerreotype has risen.

Your interesting account of the experiments of Mr. Wattles

was entirely new to me, and is another among the many evidences

that when the age is fully ripe for any great discovery,

it is rare that it does not occur to more than a single mind.

Trusting that your work will meet with the encouragement which your trouble

in preparing it deserves, and with gratitude for the undeserved compliment

paid to me in its dedication,

I remain, very sincerely,

Your friend and well wisher,

E. ANTHONY.

PHOTOGRAPHY.

As in all cases of great and valuable inventions in science and art

that of Photogenic drawing. But we shall see in the progress

of this history, that like many other assumptions of their authors,

or the cotton gin.

This claim is founded upon the fact that in 1802 Mr. Wedgwood

recorded an experiment in the Journal of the Royal Institution

"A piece of paper, or other convenient material, was placed upon

a frame and sponged over with a solution of nitrate of silver;

thus obtained, yet the object could not be accomplished,

and the whole ended in failure."

This, by their own showing, was the earliest attempt of the English savans.

MOTION OF LIGHT--Rays of light are thrown off from luminous bodies

other at every point; but the particles of which each ray consists

are so minute that the rays do not appear to be impeded by each other.

proceeds in a straight line; a fact of which any one may be convinced

by going into a darkened room and admiting light only through

[hipho_1.gif]

which light proceeds, and suppose three square boards, b. c. d.

severally one, four and sixteen square inches in size be placed;

b one foot, c two feet, and d four feet from a, it will be

perceived that the smallest board b will throw c into shadow;

that is, obstruct all rays of light that would otherwise fall on c,

and if b were removed c would in like manner hide the light

from d--Now, if b recieve as much light as would fall on c whose

surface is four times as large, the light must be four times

as powerful and sixteen times as powerful as that which would

fall on the second and third boards, because the same quantity

of light is diffused over a space four and sixteen times greater.

These same rays may be collected and their intensity again increased.

or bent, as they pass from the surface of one transparent

The latter has no important bearing upon our subject.

When a ray of light falls perpendicularly upon an opaque body,

it is reflected bark in the same line in which it proceeds;

the incident ray traversed; but when a ray falls obliquely, it is

reflected obliquely, that is, it is thrown off in opposite direction,

and as far from the perpendicular as was the incident ray, as shown

at Fig. 2; a representing the incident ray and b the reflected.

[hipho_2.gif]

the incident ray, at the surface of the reflector e f, with a line c d,

perpendicular to that surface, is called the angle of incidence,

operations upon the various coverings and humors of the eye.

Smooth and polished surfaces reflect light most powerfully,

and send to the eye the images of the objects from which the light

proceeded before reflection. Glass, which is transparent--

transmitting light--would be of no use to us as a mirror,

were it not first coated on one side with a metalic amalgam,

the air, and throws them either directly in the incident line,

or in an oblique direction. The reason why trees,

instead of their own, is, that their surfaces are uneven,

and rays of light reflected from an uneven surface are diffused

Stand before a mirror and your image is formed therein,

and appears to be as far behind the glass as you are before it,

making the angle of reflection equal to that of incidence,

as before stated. The incident ray and the reflected

ray form, together, what is called the passage of reflection,

and this will therefore make the actual distance of an image

to appear as far again from the eye as it really is.

Any object which reflects light is called a radiant.

The point behind a reflecting surface, from which they appear

to diverge, is called the virtual focus.

Rays of light being reflected at the same angle at which they

fall upon a mirror, two persons can stand in such a position

that each can see the image of the other without seeing his own.

but if you stand before one a few inches shorter the whole cannot

diverging rays to diverge more, and converging rays to converge less--

formed by the reflected ray is rendered more acute by a convex than

by a plane surface, and it is the diminishing of the visual angle,

in a point, which produces the image of convex mirrors. The greater

the convexity of a mirror, the more will the images of the objects

be diminished, and the nearer will they appear to the surface.

These mirrors furnish science with many curious and pleasing facts.

Concave mirrors are the reverse of convex; the latter being rounded outwards,

the former hollowed inwards--they render rays of light more converging--

collect rays instead of dispersing them, and magnify objects while the

When incident rays are parallel, the reflected rays converge to a focus,

but when the incident rays proceed from a focus, or are divergent,

they are reflected parallel. It is only when an object is nearer to a

concave mirror than its centre of concavity, that its image is magnified;

for when the object is farther from the mirror, this centre will appear

The centre of concavity in a concave mirror, is an imaginary

the boundary of the concavity of the mirror from any one point

of the edge to another parallel to and beneath it.

but if it, in passing from one medium to another of different density,

fall obliquely, it is bent from its direct course and recedes from it,

either towards the right or left, and this bending is called refraction;

(see fig. 3, b.) If a ray of light passes from a rarer into a denser medium

it is refracted towards a perpendicular in that medium; but if it passes from

a denser into rarer it is bent further from a perpendicular in that medium.

Owing to this bending of the rays of light the angles of refraction

and incidence are never equal.

Transparent bodies differ in their power of bending light--

as a general rule, the refractive power is proportioned to

the density--but the chemical constitution of bodies as well

as their density, is found to effect their refracting power.

Inflamable bodies possess this power to a great degree.

The sines of the angle of incidence and refraction (that is,

of the angle of refraction becomes equal to the radius* of a circle,

to be refracted; this is termed total reflection.

to the circumference.

Since the brightness of a reflected image depends upon the quantity of light,

it is quite evident that those images which arise from total reflection

of light is absorbed.

I should be pleased to enter more fully into this branch

and which I hope soon to see republished in this country.

I will conclude this chapter with a brief statement of the

principles upon which the Photographic art is founded.

SOLAR and Steller light contains three kinds of rays, viz:

2. Calorific, or rays of heat.

3. Chemical rays, or those which produce chemical effects.

than others, we procure an elongated image of the luminous beam,

exhibiting three distinct colors, red, yellow and blue, which are

to be regarded as primitives--and from their interblending, seven,

as recorded by Newton, and shown in the accompanying wood cut.

These rays being absorbed, or reflected differently by various bodies,

give to nature the charm of color. Thus to the eve is given the pleasure

we derive in looking upon the green fields and forests, the enumerable

varieties of flowers, the glowing ruby, jasper, topaz, amethist, and emerald,

the brilliant diamond, and all the rich and varied hues of nature,

both animate and inanimate.

[hipho_3.gif]

Now, if we allow this prismatic spectrum (b. fig. 3.) to fall upon

any surface (as at c.) prepared with a sensitive photographic compound,

to the intensity of the light of any particular colored ray,

covered with a very sensitive photographic preparation.

(5, fig. 3) over limits of which all chemical change is prevented.

A similar action is also produced by the lower end of the red ray c;

(as at d). The most active chemical change, you will percieve,

is produced by the rays above the yellow a; viz. 4, 3, 2 and 1

(as at b) the green (4) being the least active, and the blue

(3) and violet (1) rays the most so, the action still continuing

[hipho_4.gif]

Suppose we wish to copy by the Daguerreotype, or Calotype process,

portion of the yellow and red rays entering into the composition of both--

and the imperfections of a Daguerreotype portrait of a person with a

freckled face depends upon the same cause.

A yellow, hazy atmosphere, even when the light is very bright,

will effectually prevent any good photographic result--

it not unfrequently happens that the most anoying failures

arise from this agency of a yellow medium. A building

directly into the operator's room will have the same effect.

Daguerreotypists, being ignorant of these facts, are very apt

In selecting subjects, all striking contrasts in color should

be avoided, and sitters for portraits should be cautioned

not to wear anything that may produce the effect spoken of--

dark dresses always being the best.

The action of light both combines and decomposes bodies.

For instance, chlorine and hydrogen will remain in a glass vessel without

alteration if kept in the dark; but if exposed to the rays of the sun,

they immediately enter into combination, and produce hydrochloric acid.

On the other hand, if colorless nitric acid be exposed to the sun,

it becomes yellow, then changes to red, and oxygen is liberated

by the partial decomposition effected by the solar rays.

Of the organic substances none are more readily acted upon by light

have the power of restoring themselves to their original condition in

the dark. This is more remarkably displayed in the iodide of platinum,

exposed surfaces, but speedily loses it by bleaching in the dark.

The ioduret of Daguerre's plate, and some other iodides, exhibit the

same peculiarity--This leads us to the striking fact, that bodies

which have undergone a change of estate under the influence of day-light

Possibly the hours of night are as necessary to inanimate nature as they

are to the animate. During the day, an excitement which we do not heed,

unless in a state of disease, is maintained by the influence of light

probably all the elements, are equally liably to change under

the sun's influence. This fact may be of benefit to engravers,

for if steel can be made to take photographic impressions,

the more laborious process of etching may be dispensed with.

In fact, in the latter part of this work, a process is described

for etching and taking printed impressions from Daguerreotype plates.

but future experiments may accomplish some practical discovery

of intrinsic value to the art of engraving.

A very simple experiment will prove how essential light is to the coloring

of the various species comprising the vegetable and animal kingdoms.

remain unaltered; but if the chlorine alone be previously exposed to the sun,

the chlorine thus solarised will unite with the hydrogen in the dark.

Sulphate of iron will throw down gold or silver from their solutions slowly

in the dark; but if either solution be first exposed to sunshine, and the

mixture be then made, in the dark, the precipitation takes place instantly.

Here is again, evidence of either an absorption of some material agent from

the sunbeam, or an alteration in the chemical constitution of the body.

It was from understanding these principles and applying them that philosophers

were enabled to produce the Calotype, Daguerreotype, &c. For the effects

and action of light on the camera, see Chapter V.

Some advances have been made towards producing Photographic

impressions in color--the impossibility of which some of our

best and oldest artists have most pertinaciously maintained.

ray for ray, on paper spread with the juice of the Cochorus Japonica,

as an impossibility.

That great advantages have resulted, and that greater still will

result from the discovery of the Photographic art, few will deny.

minute details, renders it of much value to the painter; but a few minutes

sufficing to take a view that formerly would have occupied several days.

Its superiority in portraits, over miniature or oil painting has been

tacitly acknowledged by the thousands who employ it to secure their own,

artists who are weekly, aye daily springing up in every town and village

in the land.

THEIR PHOTOGRAPHIC APPLICATION."

OXIDE OF SILVER exposed for a few hours to good sunshine,

passes into a more decided olive color, than characterises it

when first prepared by precipitation from nitrate of silver.

and the covered parts, are found much darker, than those on which

the light has acted directly. In some instances where the oxide

process in some parts, after a few days exposure, is noticed.

Oxide of silver disolved in ammonia is a valuable photographic fluid;

portion of organic matter renders it exceedingly liable to change

under luminous influence.

If a piece of nitrated paper is placed upon hot iron,

or held near the fire, it will be found that at a heat just

below that at which the paper chars, the salt is decomposed.

Where the heat is greatest, the silver is revived,

and immediately around it, the paper becomes a deep blue;

beyond this a pretty decided green color results,

and beyond the green, a yellow or yellow brown stain is made.

This exhibits a remarkable analogy between heat and light,--

before spoken of in chap. II--and is of some practical

importance in the preparation of the paper.

of rays of light by the spectrum has already been described on pages 22

and its maximum about the centre of the blue, although the action up to

beyond this point the action is very feeble.

previously darkened, by exposure to sunshine under cupro-sulphate

of ammonia, the phenomena are materially different.

The photographic spectrum is lengthened out on the red or negative

side by a faint but very visible red portion, which extends

The tint of the general spectrum, too, instead of brown is

dark grey, passing, however, at its most refracted or positive

end into a ruddy brown.

CHLORIDE OF SILVER.--This salt of silver, whether in its

precipitated state, or when fused, changes its color to a fine

bluish grey by a very short exposure to the sun's rays.

If combined with a small quantity of nitrate, the change is

more rapid, it attains a deep brown, then slowly passes into

a fine olive, and eventually, after a few weeks, the metalic

Great differences of color are produced on chlorides of silver

precipitated by different muriates. Nearly every variety

olive color, the following examples, therefore, have reference

to a few minutes exposure, only, to good sunshine; it must

speedly to a pure dark brown, and muriatic acid, or aqueous chlorine,

do not appear to increase the darkening power beyond the lilac

to which the pure chloride of silver changes by exposure.

This difference of color appears to be owing to the admixture

of the earth or alkali used with the silver salt.

The prismatic impression on paper spread with the chloride of

silver is often very beautifully tinted, the intensity of color

varying with the kind of muriate used. Spread paper with muriate

of ammonia or baryta and you obtain a range of colors nearly

corresponding with the natural hues of the prismatic spectrum.

Under favorable circumstances the mean red ray, leaves a red impression,

which passes into a green over the space occupied by the yellow rays.

Above this a leaden hue is observed, and about the mean blue ray,

into black, and through the most refrangible rays it gradually

Not only the extreme red ray exerts this very peculiar property,

In photographic drawing this salt is of the utmost importance.

portion of this work.

IODIDE OF SILVER--Perfectly pure, undergoes very little change

under the influence of light or heat; but if a very slight

more senitive than the chloride

The spectrum impressed upon paper prepared with a weak solution of

while the most refrangible rays impress a ruddy snuff-brown,

the change of tint coming on rather suddenly about the end of

the blue or beginning of the violet rays of the luminous spectrum.

Beyond the extreme violet rays, the action rapidly diminishes,

but the darkening produced by these invisible rays, extends a

very small space beyond the point at which they cease to act on

In its photographic application, it is, alone, of very little use;

With gallic acid and the ferrocyanate of potash it forms two of the most

sensitive photographic solutions with which we are acquainted.