IM- PROVEMENTS IN PHOTOGRAPHY
Year: 1868

page_text: PROVISIONAL SPECIFICATION left by Clinton Edgcumbe Brooman
at the Office of the Commissioners of Patents, with his Petition, on
the 11th April 1868.-A communication from abroad by Augustin
Marion, of Paris, France.
I, CLINTON EDGCUMBE BROOMAN, of the Firm of Robertson, Brooman,
and Company, of 166, Fleet Street, in the City of London, Patent
Agents, do hereby declare the nature of the said Invention for "IM-
PROVEMENTS IN PHOTOGRAPHY," to be as follows:-
The object of this Invention is to simplify the ordinary operations of
the process of photographing with charcoal (charbon), and to improve
the results which it permits of obtaining.
It is known that in this process in order to reproduce upon gelatinized
paper the image of the original or primitive picture (cliché) two
successive transfers are necessary, which are effected one from the black
gelatinized paper after it has received the image from the picture by
insolation upon paper prepared with caoutchouc, and the other from
the paper prepared with caoutchouc after it has been treated by benzine
the gelatinized paper, which furnishes the final proof.
upon
The present process, on the contrary, which starts with the application
of the collodionized pellicle (prepared with collodion and castor oil)

page_text: dispenses with the intervention of the paper prepared with caoutchouc
and of the benzine, it gives from the first a positive returned (retournée)
proof, which by a single transfer upon albumenized or gelatinized paper
is produced in its natural sense.
One important advantage of this process is that it gives directly proofs
with charcoal on albumenized paper, and this has never been accom-
plished before; this advantage is principally owing to the method
I employ of coagulating the albumen either by steam or boiling water.
From the following description the three characteristic features of
this Invention will be readily understood, viz., the application of the
collodionized pellicle, the production of proofs with charcoal upon
albumenized paper, and the method of coagulating the albumen by
steam or boiling water.
Taking a negative picture on glass of the object to be reproduced
I commence by transferring the image upon the collodionized pellicle.
If the picture is new this is casily accomplished. The glass being
placed flat the pellicle is spread over it, time being allowed to permit
its even extension in every direction. The glass is then lifted to allow
the excess of varnish to run off, and it is then placed upon a drainer to
dry, and the pellicle is then raised, taking with it the layer of collodion
and the image which it bears. When the picture is varnished the
operation is not so easy, it being necessary to dip the glass in water for
some hours in order to render the removal of the collodion morc casy; it
is then dried and treated as has been described with reference to new
pictures until the removal of the image. If that does not readily take
place the glass should be again placed in water and the removal allowed
to take place of itself. I thus obtain ad libitum with pictures transferred
upon the collodionized pellicle positive proofs which are either returned
(retournées) or in their natural position. Thus the collodionized pellicle
which receives the image from the picture plays the same part as the
picture itself in the ordinary process.
The gelatinized paper prepared with charcoal which I employ is made
by spreading upon paper a regular layer of gelatine, colored black,
sepia, or other tint. To scnsitize it I plunge it into a solution of G
parts of bichromate of potash to 100 parts of water and allow it to dry.
Thus prepared I submit it to insolation, the colored side applied to thic
pellicle. The time of exposure is difficult to state precisely, it being a
matter for observation, and varying between 2 and 10 minutes according

page_text: to the light and the nature of the original picture operated on. When the
paper has been exposed the desired time it is placed in order to cleanse
it into cold water, changed several times for an hour or less; a great
number of sheets may be placed in the same vessel filled with water.
The gelatine swells or becomes distended in the cold water, and the
image begins to appear in relief upon the black layer of gelatine after
the dechromatizing of the gelatine left at liberty. The subsequent
operations may take place in the light.
It is now necessary to transfer this returned (retournèe) image upon
the albumenized paper. The means I use for this purpose are an
essential feature of this Invention. The albumenized paper is floated on
its back upon pure water, the layer of black gelatine is placed upon the
layer of albumen and lifting together the two sheets applied one against
the other they are submitted to a rather heavy pressure between two
plates of glass. The sheets should all be of the same size, as otherwise
the pressure will be partial and imperfect and the proof destroyed.
After remaining under pressure an hour or two the two papers are hung
up to dry. After they have been brought to the required degree of
dryness they are submitted to the action of steam in a box hermetically
closed. The steam which has no power on the gelatine coagulates the
albumen and leaves the gelatine in its soluble state. Boiling water
may be substituted for the jet of steam. The two papers are now put
into hot water to be separated. The bichromatized gelatine left at
liberty dissolves, leaving to the albumenized paper the image which
from being latent and inverse, as it was originally, is now visible and
doubly unalterable.

page_text: PROVISIONAL SPECIFICATION left by Clinton Edgcumbe Brooman
at the Office of the Commissioners of Patents, with his Petition, on
the 11th April 1868.-A communication from abroad by Augustin
Marion, of Paris, France.
I, CLINTON EDGCUMBE BROOMAN, of the Firm of Robertson, Brooman,
and Company, of 166, Fleet Street, in the City of London, Patent
Agents, do hereby declare the nature of the said Invention for "IM-
PROVEMENTS IN PHOTOGRAPHY," to be as follows:-
The object of this Invention is to simplify the ordinary operations of
the process of photographing with charcoal (charbon), and to improve
the results which it permits of obtaining.
It is known that in this process in order to reproduce upon gelatinized
paper the image of the original or primitive picture (cliché) two
successive transfers are necessary, which are effected one from the black
gelatinized paper after it has received the image from the picture by
insolation upon paper prepared with caoutchouc, and the other from
the paper prepared with caoutchouc after it has been treated by benzine
the gelatinized paper, which furnishes the final proof.
upon
The present process, on the contrary, which starts with the application
of the collodionized pellicle (prepared with collodion and castor oil)

page_text: dispenses with the intervention of the paper prepared with caoutchouc
and of the benzinc, it gives from the first a positive returned (retournée)
proof, which by a single transfer upon albumenized or gelatinized paper
is produced in its natural sense.
One important advantage of this process is that it gives directly proofs
with charcoal on albumenized paper, and this has never been accom-
plished before; this advantage is principally owing to the method
I employ of coagulating the albumen either by steam or boiling water.
From the following description the three characteristic features of
this Invention will be readily understood, viz., the application of the
collodionized pellicle, the production of proofs with charcoal upon
albumenized paper, and the method of coagulating the albumen by
steam or boiling water.
Taking a negative picture on glass of the object to be reproduced
I commence by transferring the image upon the collodionized pellicle.
If the picture is new this is easily accomplished. The glass being
placed flat the pellicle is spread over it, time being allowed to permit
its even extension in every direction. The glass is then lifted to allow
the excess of varnish to run off, and it is then placed upon a drainer to
dry, and the pellicle is then raised, taking with it the layer of collodion
and the image which it bears. When the picture is varnished the
operation is not so easy, it being necessary to dip the glass in water for
some hours in order to render the removal of the collodion more casy; it
is then dried and treated as has been described with reference to new
pictures until the removal of the image. If that does not readily take
place the glass should be again placed in water and the removal allowed
to take place of itself. I thus obtain ad libitum with pictures transferred
upon the collodionized pellicle positive proofs which are either returned
(retournées) or in their natural position. Thus the collodionized pellicle
which receives the image from the picture plays the same part as the
picture itself in the ordinary process.
The gelatinized paper prepared with charcoal which I employ is made
by spreading upon paper a regular layer of gelatine, colored black,
sepia, or other tint. To sensitize it I plunge it into a solution of 6
parts of bichromate of potash to 100 parts of water and allow it to dry.
Thus prepared I submit it to insolation, the colored side applied to the
pellicle. The time of exposure is difficult to state precisely, it being a
matter for observation, and varying between 2 and 10 minutes according

page_text: to the light and the nature of the original picture operated on. When the
paper has been exposed the desired time it is placed in order to cleanse
it into cold water, changed several times for an hour or less; a great
number of sheets may be placed in the same vessel filled with water.
The gelatine swells or becomes distended in the cold water, and the
image begins to appear in relief upon the black layer of gelatine after
the dechromatizing of the gelatine left at liberty. The subsequent
operations may take place in the light.
It is now necessary to transfer this returned (retournèe) image upon
the albumenized paper. The means I use for this purpose are an
essential feature of this Invention. The albumenized paper is floated on
its back upon pure water, the layer of black gelatine is placed upon the
layer of albumen and lifting together the two sheets applied one against
the other they are submitted to a rather heavy pressure between two
plates of glass. The sheets should all be of the same size, as otherwise
the pressure will be partial and imperfect and the proof destroyed.
After remaining under pressure an hour or two the two papers are hung
up to dry. After they have been brought to the required degree of
dryness they are submitted to the action of steam in a box hermetically
closed. The steam which has no power on the gelatine coagulates the
albumen and leaves the gelatine in its soluble state. Boiling water
may be substituted for the jet of steam. The two papers are now put
into hot water to be separated. The bichromatized gelatino left at
liberty dissolves, leaving to the albumenized paper the image which
from being latent and inverse, as it was originally, is now visible and
doubly unalterable.