IMPROVEMENTS IN PHOTO- GRAPHY AND IN THE PROCESS OF PRODUCING PRINTING SURFACES AND OTHER
Year: 1866

page_text: LETTERS PATENT to Michael Henry, of 68, Fleet Street, in the City of
London, Patent Agent, for the Invention of "IMPROVEMENTS IN PHOTO-
GRAPHY AND IN THE PROCESS OF PRODUCING PRINTING SURFACES AND OTHER
Sealed the 26th June 1866, and dated the 14th February 1866..
COMPLETE SPECIFICATION filed by the said Michael Henry at the Office
of the Commissioners of Patents, with his Petition and Declaration, on
the 14th February 1866, pursuant to the 9th Section of the Patent Law
Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MICHAEL.
HENRY, of 68, Fleet Street, in the City of London, Patent Agent, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN PHOTOGRAPHY,
AND IN THE PROCESS OF PRODUCING PRINTING SURFACES AND OTHER LIKE SURFACES
BY THE AID OF PHOTOGRAPHIC AGENCY," communicated to me from abroad by thie
Chevalier Henry Avet, of 33, Boulevart Saint Martin, Paris, France, and in
what manner the same is to be performed, to be particularly described 'and
ascertained in and by the following statement thereof as communicated to nic,
that is to say:
This Invention has for one object to produce printing, surfaces and other
like surfaces. For this purpose an image is first produced by any ordinary

page_text: photographic process on a plate of glass or other solid transparent or
translucent substance, and on the collodion film or collodion surface of such
plate is next applied gelatine, gum, or other organic matter mixed with
bichromate of potash; the light acts on the organic matter through the body
of the plate, so that when the parts unaffected by the light are dissolved there
remains on the plate a subject or design in relief adhering to the photographic
representation or image first produced. A metal surface suitable for printing
and other similar purposes (such as embossing and figuring) may be obtained
by electro-metallurgy from such relief or from an impression taken therefrom.
I now proceed to describe more particularly in what manner this may be
carried into effect.
An image or representation of any desired object is first produced on a
plate of glass or other solid transparent substance or solid translucid sub-
stance by any known ordinary photographic process. A solution (which by
preference is a concentrated solution) is prepared by dissolving gelatine, gum,
or other organic substance to which bichromate of potash is added, whereby
a sensitive agent or composition is produced, so that the parts which receive
the action of the light become insoluble in water or in ordinary solvents. The
organic substances which may be used for making this solution are too
numerous to be stated in detail, but I may mention that, all descriptions of
gums are proper for the purpose. The following are suitable proportions for
composing the solution:-4 or 5 parts of gelatine to 1 part bichromate of
potassa. I do not restrict myself to these proportions. When gelatine or
gum is used the solution is made by preference with warm water, either
distilled or otherwise. A shallow edge or rim of wax is raised or formed
on the plate, to prevent the solution from running off it, and to determine
the thickness of relief to be formed on it. A film or layer of the aforesaid
solution (gelatine or other organic substance mixed with bichromate of potash)
is then spread on the plate on the collodion side thereof, that is, on the side
on which the collodion has been applied. The plate is next exposed to the
action of light on the non-collodionized side, that is to say, so that the light
may pass through the body of the plate to the opposite or collodion side. In
other words the plate is so disposed that the light first strikes on the surface
on which there is no collodion, and then through the thickness of the plate to
the collodion film or surface, and to the layer of organic substance thereon.
During the exposure care is taken that the collodion side shall not be injured.
When the layers of sensitizing or organic solution are rather thick, the plate
should be protected from the lateral action of the diffused light, and so
disposed that it shall only catch the vertical rays. The time during which

page_text: the exposure lasts is regulated by experience according to the state of the
weather; the nature of the plate, and the intended result to be obtained.
After the plate has been exposed the next step taken is to proceed in the
dark chamber to dissolve the parts of the film or layer of bichromatized
organic substance which the black tints and half tints of the plate have wholly
or partially preserved from the action of light. When the plate is dry the
subject appears raised or in relief on its surface; its delicacy corresponds with
that of the photographic representation (to which it adheres). The height of
rélief of the various parts of the subject so produced is proportionate to the
degree of transparency of the corresponding parts of the image first produced
on the plate. If the relief so produced be insufficient the process is repeated
by spreading on the plate a second film or layer of the aforesaid agent
(organic substance and bichromate), care being taken first to remove any
anti-photogenic tint which the plate may have acquired from the bichromate ;
such tint may be removed by using nitric acid or any other ordinary known
chemical process for the purpose. The subject produced in relief as described
is then metallized by any ordinary means; for example, it is first coated with
a metallizing or conducting solution of nitrate of silver, and metal is then
precipitated or deposited upon it by electrotype or electro-metallurgy. Or
else an impression is first taken off from the raised surface, such impression is
taken in a sheet of plastic material, as, for example, gutta percha, to which
Venice turpentine and a little spirits of turpentine are added (according to
the temperature at which the process is performed), and then the metallic
coating is deposited or precipitated on this impression. By these means,
therefore, a negative or a positive obtained from such negative is dealt with,
and a first impression produced by exposing a plate in the camera directly on
the collodion side (that is to say) the light is applied so as to reach the
collodion side through the thickness of the glass. By this method various
combinations may be obtained, and the subject produced on the metallic plate
finally obtained may be either sunken or in relief. Instead of spreading upon
the plate bichromatized gelatine or other organic substance in a state of
solution, the organic substance may be spread in sheets or films, that is to
say, a sheet of gelatine or other organic substance is prepared like the sheet
gelatine of commerce, and sensitized by mixture with a solution of bichromate
of potash, and it is then applied on the plate on which the first impression or
image is taken. It is placed thereon in a manner similar to that adopted in
applying gelatine to paper used in taking photographic positives.
The above process is applicable generally in cases in which printing,
embossing, or figuring surfaces produced by engraving or otherwise. are used,

page_text: A drawing, picture, or engraving made on paper may serve as an original,
that is to say, as the subject of the printing surface to be produced. Such
original may be on a larger scale than that desired for the required result or
subject of the printing surface, and it may be reduced as desired by ordinary
means employed in photography.
Engravings, drawings, maps, autographic manuscripts, and other matters
may be by these means converted into or form the subject of printing surfaces,
the subject appearing thereon either sunken or in relief.
Another application of the process relates to the figuring of porcelain,
For this purpose a
biscuit, or other transparent or translucent materials.
photographic representation of an article presenting half tints, such, for
example, as a statue, portrait, landscape, or oil or water picture is first taken,
and a relief or raised surface produced therefrom by the process herein-before
described, and this process is carried on in such manner or pursued to such an
extent as to obtain a sharp or strong degree of relief, and the metallic surface
obtained therefrom is used for figuring transparencies of china, biscuit, or
other like translucent materials, thus producing thereon a representation of the
original object photographed. Or if the surface be in less relief it may be
used for printing in inks.
The next object of this Invention consists in producing surfaces with a
grain, or as it may be called an artificial grain. For this purpose, according
to this part of the Invention, a pattern or design is made by producing a
photographic image on a surface, such image consisting of a representation of
very fine white lines. on an antiphotogenic colored ground, or of very fine
antiphotogenic colored lines on a white ground. The lines may be produced
either before or after photographing (or producing a photographic image of)
the subject of the photographic work or picture on which such grain is to be
represented. Or the representation of the subject or object and of the grain
may be produced or photographed simultaneously by using two plates.
A
now proceed more particularly to describe in what manner this part of
the Invention may be performed. A pattern is first prepared consisting of
very fine white lines on an antiphotogenic colored ground, or vice versa. The
pattern used by preference for the purpose is produced by using a large frame
covered with black cloth, over which is stretched a piece of white net.
photographic negative is then made by photographing on the same plate both
the net and the object to be represented, that is to say, an image of the net
and an image of the intended subject to be represented are taken consecutively
on the same plate. Either may be taken first. The net may be reduced to
any required scale.. Both are taken on the same film or surface of collodion.

page_text: The two images are produced by two separate consecutive exposures. The
plate is next placed in the dark room, and the images are developed and are
then fixed. The net presents a representation of regular and fine opaque
lines, which do not at all interfere with the distinctness of the subject nor the
delicacy of detail. From these plates printing surfaces and other like surfaces
may be obtained by treating the said plates according to the process first
herein described.
As the fine opaque lines produced by the net form an uniform reserve
against the action of the light the relief obtained on the plate necessarily
forms a series of small regular dome-shaped convexities proportionate in
height to the action of the light through the tints of the image of the object.
When this relief is reproduced on the metal as a sunken design a regularly
and artificially grained surface is obtained, in which the black and half tints
are regulated by the depth of the grain, or (when impressions are taken on
paper) by the thickness of ink. Sometimes the process may be performed as
follows: A photographic negative of the pattern which is to represent the
grain is first made, this pattern consisting of white lines on a black ground, as
above explained; and a negative is also taken of the subject to be represented.
These negatives are placed together with their collodion films or surfaces in
contact. These are placed in a photographic apparatus constructed for
operating by the transparent process, whereby an image is produced liy a
single operation, that is to say, with only one exposure. Printing surfaces
and similar surfaces may be formed from these plates, according to the process
first described in this Specification. In these plates the object is positive, and
the grain is formed by fine transparent lines, whence it follows that in the
relief produced on them by the first-described process the grain forms small
concavities, the depth of which is not directly proportionate to the action of
the light through the tints of the image, but is formed by the difference
between the action of light and the regular action exerted through the small
transparent lines. To obtain from such a relief a metal printing surface with
the subject thereon sunken the relief is subjected to two electro-metallurgical
operations, or a metal mould is first taken from it, and it is then electro-
typed.
When I wish to produce a portable grained surface suitable for being
used when travelling or away from the studio a negative is taken from a
pattern consisting of black lines on white ground, the design being reduced to
any desired extent. In one of the two consecutive exposures in the camera
this plate is used in the transparent process, or else a positive is taken on
paper from a negative taken from a pattern produced by white lines on a

page_text: black ground. By these means a portable pattern plate for a grained surface
is obtained. Or this grained plate is applied on another plate with their
collodion films or surfaces in contact, and a grained plate is thus obtained by
a single exposure; the image of the grain on this last surface is formed by
transparent instead of opaque lines. This method of obtaining artificial
grained surfaces may be applied for reproducing various subjects which
present half tints, such as engravings and lithographs.
The Invention has next for object to obtain superior photographs or photo-
graphic positives. For this purpose, according to this Invention, negatives'
produced in the manner similar to that herein-before described in the process
for producing grained plates or surfaces may be employed when taking photo-
graphs or photographic positives or prints. By employing such improved
negatives a superior artistic effect will be obtained in printing positives or
photographs on paper..
By the expression collodion side or surface used in the present Specification
I mean the side or surface of the plate on which the collodion film is applied.
By the expression non-collodionized I mean the side or surface on which the
collodion is not applied.
Instead of using bichromate of potash for admixture with gelatine, gum, or
other organic substance as above described, bichromate of ammonium may be
used.
I wish it to be understood that one method of producing printing surfaces
and other like surfaces according to this Invention consists in the following
combination of processes herein-before described, namely, first in producing an
artificial grain on plates, then in obtaining a raised or sunken design or
subject on such plates, and, lastly, in obtaining a metallic surface from the
same, the design or subject thereon being raised or sunken, all being effected
according to the respective processes described in this Specification.
Having now described the nature of the said Invention, and in what
manner the same may be performed, I declare that I claim,-
First, the method of obtaining surfaces suitable as printing surfaces or other
like surfaces by applying gelatine, gum, or other organic substance mixed
with bichromate of potash or of ammonium on a plate of transparent or of
translucent material on which a photographic image or representation has
been produced, and causing the light to act on such organic substance through
the body or thickness of the plate, whereby when the parts unaffected by the
light are dissolved, a subject in relief will remain thereon, from which a metal
surface may be obtained, all substantially as described.
Second, the method of producing a grain on photographic surfaces by using

page_text: a device composed of fine white lines on an antiphotogenic colored ground or
of antiphotogenic colored lines on a white ground before, after, or while
obtaining an image or representation of the subject of the photograph,
substantially as described.
Third, the employment in photography of the modes of obtaining a "grain,"
substantially as described.
Fourth, the production of printing surfaces and other like surfaces by the
employment of any of the processes described for obtaining artificial grain in
combination with the processes of obtaining a raised or a sunken subject, and
of producing a metal surface therefrom, all as described.
In witness whereof, I, the said Michael Henry, have hereunto set my
hand and seal, this Fourteenth day of February, in the year One
thousand eight hundred and sixty-six.
Witness,
M. A. GREEN,
68, Fleet Street,
London.
M. HENRY. (L.S.)