IMPROVEMENTS IN PHOTOGRAPHY
Year: 1856

page_text: LETTERS PATENT to Claude Langlois,, of Bath, in the County of Somerset,
Artist, for the Invention of "IMPROVEMENTS IN PHOTOGRAPHY."
PROVISIONAL SPECIFICATION left by the said Claude Langlois at the
Office of the Commissioners of Patents, with his Petition, on the 26th
September 1856.
I, CLAUDE LANGLOIS, of Bath, in the County of Somerset, Artist, do hereby
declare the nature of the said Invention for "IMPROVEMENTS. IN PHOTOGRAPHY,"
to be as follows:-
The improvements relate to a combination of means by which greater.
clearness, speed, and economy are secured in the process of obtaining
photographic, pictures.
I employ a camera constructed with capability for the operator to take the
focus in front, or that side next the person or object to be taken; also, the
moveable frame, containing the prepared glass or other material for receiving
the image, is made to turn upon centres within the camera, so as at once to
serve for ascertaining and fixing the correct focus, and then of receiving the
image on the prepared glass; also, in place of employing a cover to enclose

page_text: the head of the operator whilst determining the focus, I form eye holes.or
apertures, each with enclosing means, to be opened when looking through, and
closed when not so in use; also, to the application of adjusting means to the
parts carrying the lens, so as to obtain a capability of varying the centre
thereof in relation to the parts of the surface of the glass or other material
upon which the object is to be received; also, to the application of adjustable
feet to the camera, by which to facilitate levelling or tilting the same.
By the use of a camera such as I have described, I obtain, in manner
such as well known, a negative picture, I immediately remove the same
to a dark room, the only light to which is obtained by artificial means,
and I enclose the lantern or other light employed as the illuminating media,
except at a small aperture from which the light is allowed to fall upon the
printing tablet in measured quantity, and by the aid of any suitable time-
keeper I am enabled to apportion the same time to each impression, by which
I find greater certainty and celerity in the amount of light employed, than
when obtaining the impressions from the negative in the ordinary way by
natural light, and the prints so obtained are finer and freer from foreign
color.
Also, the improvements relate to employing plaster of Paris, hardened by
spermacetti wax, or gum, as a means of obtaining positive pictures. 1 apply,
first, a thin layer of plaster, and before this "sets," or whilst it is in a semi-fluid
state, I apply a layer of wool or muslin, and then another layer of plaster, and
so on till the thickness of back I require is obtained, when I apply card, wood
or thin metal, which may be stuck to it by means of gum shellac. The
surface is preserved by several coats of varnish, which make the whole solid
and durable.
Also, the improvements relate to employing, for the purpose of backing
pictures taken on glass, either whilst on such glass or after removal therefrom,
wood, papier maché, paper pulp, japanned metal, silvered glass, tale, alabaster,
and marble.
Also, to varnishing the transparent positive pictures on glass or other of the
above-named materials, and coloring them on the front or at the back with dry
colors, and afterwards warming the varnish to fix them.
Also, to producing similar pictures on collodion, albumen, or other vehicle
by a weak natural light.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed'
by the said Claude Langlois in the Great Seal Patent Office on the 26th
March 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CLAUDE
LANGLOIS, of Bath, in the County of Somerset, Artist, send. greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters.
Patent, bearing date the Twenty-sixth day of September, in the year of our
Lord One thousand eight hundred and fifty-six, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Claude Langlois, Her special licence that I, the said Claude Langlois, my.
executors, administrators, and assigns, or such others as I, the said Claudo
Langlois, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN PHOTOGRAPHY,"
upon the condition (amongst others) that I, the said Claude Langlois, my
executors or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be per-
formed, and cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Claude Langlois, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say :-
This Invention consists in a method of arranging photographic cameras so
that the operator can adjust the focus from the front, or that side next the
person or object to be taken, and also so that the moveable frame for containing
the prepared glass or other material for receiving the image may also be used
for ascertaining the correct focus; and for these purposes I prefer to arrange
the camera in the following manner:-On one side of the camera I arrange
folding doors hinged to the front and back, and closing together in the middle.
The door which is hinged to the front end of the camera has a hole through it
sufficiently large for the passage of the hand of the operator, and it is through
this hole that he looks when focusing. For greater convenience, the portion

page_text: of the door through which this hole is made is so arranged as to be inclined at.
an angle of 45 degrees to the front of the camera when the door is closed.
The slide for containing the plate is made of such a size as to close or fill the
end of the camera, and it has a hinged door at the front and at the back, one
for introducing the plate and the other to be opened for exposing it; the frame
thus constructed is mounted on a round foot of wood, under which, and at its
centre, is a short projecting stud or pin, which drops into a hole at the bottom
of the camera. The door at the back of the slide is made white, and is used
for focusing upon, and when the slide is first put into the camera, this side is
turned to the lens, and stops are employed to enable the operator to place, it
exactly parallel with the lens. When the focus is adjusted, the slide is turned
half round, and the slide is so arranged that when it is turned round the pre-
pared surface of the plate exactly occupies the place previously occupied by the
white surface of the door. The operator opens the front door of the slide so
as to expose the plate by introducing his hand through the hole in the door. ;
and in order to prevent the entrance of any light through this hole, it may
have a sleeve of a light proof fabric attached round it. I furnish the camerà
with screw feet to facilitate its adjustment to any required inclination:
This Invention also consists in backing photographic pictures with plaster of
Paris. To obtain a picture suitable for backing in this manner, I take, first;
a negative picture in the ordinary way on glass with collodion, and from this
negative picture I print a positive picture on another plate, coated with
collodion, and for this operation I prefer to employ the light of a lamp, as I
find that I can in this way obtain more uniform results than when daylight is
employed. The positive picture is developed and affixed in tho ordinary
manner. To back this picture with plaster of Paris, I mix the plaster into a
paste, just such as will flow easily, and pour it on to the collodion surface of
the plate, and over the plaster I apply a piece of muslin or other open fabric;
and then pour on more plaster, and so on until enough has been put on to form
the thickness on the back required. When I'wish to remove the glass from
the picture, and to leave it on the surface of the plaster, I coat thei plate, before
printing the picture, with a thin solution of gum, which I allow to dry on, and
then, when the picture has been printed and backed; I soak it in warm water,
which dissolves the gum and leaves the picture on the plaster'; when dry, the
picture has a shining appearance; arising from the presence of the collodion,
and to remove this I wash the surface with pure ether! In order to render
the picture more suitable for colouring, I saturate the plaster with sperinaceti
or wax, which I for this purpose, melt in a dish, and I dip the back of the

page_text: picture into the melted matter, and allow it to remain until the plaster has
sucked up the spermaceti or wax almost to the surface of the picture. To
strengthen the plaster, I cement it, by shell lac or otherwise, to a back of metal,
millboard, or other suitable material.
In witness whereof, I, the said Claude Langlois, have hereunto set my
hand and seal, this Twenty-sixth day of March, in the year of our Lord
One thousand eight hundred and fifty-seven.
Witness,
GEO. PITT.
CLAUDE LANGLOIS. (L.S.)