A PORTABLE LABORATORY SPECIALLY INTENDED FOR PHOTOGRAPHIC EXCURSIONS
Year: 1867

page_text: PROVISIONAL SPECIFICATION left by William Edward Gedge at the
Office of the Commissioners of Patents, with his Petition, on the 3rd
October 1867. A communication from abroad by Hippolyte Rochat, of
39, Faubourg St. Martin, Paris, France.
1, WILLIAM EDWARD GEDGE, of the Firm of John Gedge and Son, of
No. 11, Wellington Street, Strand, in the County of Middlesex, Patent
Agent, do hereby declare the nature of the said Invention for "A PORTABLE
LABORATORY SPECIALLY INTENDED FOR PHOTOGRAPHIC EXCURSIONS," a communica-
tion to me from abroad by Hippolyte Rochat, of 39, Faubourg St. Martin,
Paris, France, to be as follows:-
This apparatus is composed of a rectangular wooden case hermetically
joined, the dimensions of which are regulated by those of the basins and
frame intended for the operations. The normal or ordinary plate requires
interiorly from about 20 to 22 inches in length by about 14 inches in breadth,
and an equal height. The top or lid opens from the front backwards to a
width of about 10 inches and from the back forwards in a breadth of a little
over 2 inches. The middle part remains fixed. These two openings are
provided with yellow glasses lighting the interior. A moveable covering
intended to prevent the reflection of the light on the surface of the glasses
when it is raised and to preserve these from contact with exterior objects

page_text: when it is lowered is joined by means of hinges to the fixed part of the lid ;
the sides or overlaps of this shade slide on the exterior of the sides of the
case, covering the openings of these sides, and are fixed by the operator at the
desired height by means of an adjusting screw. The two sides and the
front of the apparatus are pierced about 1 to 12 inches above their centres
with a round opening of from 5 to 6 inches in diameter, to which is fitted a
sleeve of a thick black fabric about 8 inches long and terminating in an elastic
wristband. A groove intended to receive the frame hollow or projecting
according to the construction of this latter is placed at the bottom of the
case at the end, and at the height of the basins, it serves to give to this frame
the necessary slope or inclination for preventing the fall of the glass plates
into the interior of the apparatus. A small spiral spring presses against the
frame when the opening by which it has been introduced is closed, it keeps
it in its position and adds to the facility of seizing the glass plate as both
bands may be employed; lastly, four sliding feet placed at the angles permits
the raising of the laboratory and placing it horizontally on any ground. The
dimensions of this apparatus according to the sizes to be obtained may be
determined in the following manner :-
Length. The breadth of the two basins suffices, as the blotting paper
may be placed even more commodiously on the side of the covering of the
basins which presents itself when the basin with the silver bath is uncovered.
Breadth. The length of the basins plus the distance from the groove
intended to receive the frame to the back of the case calculated according to
the inclination which it is desired to give to this frame.
Height. That of the frame starting from this groove.
Method of Operating.-The photographer changes nothing in his ordinary
manipulations; arrived on the spot for his operations the case is set horizontally,
two basins of equal, dimensions are placed in the interior one beside the
other, the sensitizing bath is poured into the one and the developing bath
into the other at the choice of the operator. A small flap fixed to this latter
by hinges permits their being alternately covered to prevent splashes from
one bath into the other. The glass plate collodionized in the full light is
placed in the frame, this latter is introduced into the dark chamber by the
back opening, which is reclosed, the hands passed into the sleeves take the
glass plate in this frame (which must not open from the bottom upward), it
is immersed in the silver bath, drained on the blotting paper, replaced in the
frame, brought back in the apparatus after the pose, and the developement
made in the second basin. It is afterwards withdrawn by the large opening
in front, washed, fixed, and even strengthened if necessary, in the usual

page_text: It is very useful in order to prevent the chafing of the edges of
photographs enclosed damp or unvarnished in the special boxes that the
grooves of these latter should not be square and about the thickness of the
glass plate, but triangular so that the edges of the plate have no point of
contact with them but by their extreme angles. The operations ended the
object glass, the dark chamber, the basins, flasks, and so on are placed in
the apparatus, which thus serves as a packing case and is no encumbrance.
At Fig. 1 of the accompanying Sheet of Drawing forming part of this
Provisional Specification, a, a, indicate the basins; 6, covering flap of the
basins; c, negative frame receiving the glass plate; d, shutter of the frame
open; e, e, e, shade; f, adjusting screw serving to fix the shade at the desired
height by means of the groove h; g, yellow glasses for looking into the
apparatus; i, i, openings provided with sleeves; k, blotting paper.
At Fig. 2, a indicates the back of the raised lid provided with a yellow
glass lighting the interior; b, opening for passing the frame c; d, groove for
posing the frame and keeping it inclined; m, gentle spiral spring holding the
frame; e, e, shade uplifted; f, adjusting screw for fixing the shade; h, groove
of the adjusting screw; i, opening provided with black sleeves; 0, 0, 0, sliding
feet.