Year: 1888

page_text: "
I, ALEXANDER HENRY REED, of Suffolk House, Laurence Pountney Hill, Cannon
Street, in the county of Middlesex, Engineer do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
This invention relates to certain improvements in portable Photographic Dark-
chambers, the improvements which constitute the invention being pointed out in the
following specification and claims, and illustrated in the accompanying drawing
in which:
Fig. 1 represents a perspective view of my dark-chamber.
Fig. 2 is a longitudinal vertical section in the plane az fig. 1.
Fig. 3 is a transverse vertical section in the plane y y fig. 2, and looking in the
direction of the arrows opposite to that line.
Similar letters indicate corresponding parts.
In this drawing the letter A designates a box which may be made of wood or of
any other suitable material, and which is provided at one end with a door B through
which easy access can be had to its interior. In the top of the box are secured two
panels of glass C D which are colored red, or of any suitable non-actinic color, such
as green or orange but I prefer to use a glass pane C of red color and another glass
pane D of orange color, the latter being protected by a screen E so that by placing
the box in a suitable position, said pane is protected against direct rays of light.
Another pane D¹ of red colored glass may be inserted into the end F of the box
opposite to the door B.
In the door are two arm holes G G which are closed on the inside each by means
of four flaps a, b, c, d, of cloth or any other suitable flexible material. Each of these
flaps is secured near one of its edges to the door B by tacks ee or by any other
suitable means, and to its free end which extends beyond the centre of the arm-hole,

page_text: are secured elastic cords ff, the outer ends of which are fastened to the door by
tacks gg or by any other suitable means. By the action of these elastic cords the
flaps a, b, c, d, are held in an extended position, but if the hands are pushed through
the arm-holes from the outside, the flaps yield so that the hands and arms can be
inserted to the desired extent while at the same time the light is excluded.
The great advantage of my portable dark chamber will be readily understood by
those skilled in the art. After the sensitive plate has been exposed the negative
produced by such exposure is introduced into the box A while being enclosed in the
plate holder, the door of the box being opened for this purpose. Into the box are
also placed the requisite liquids for developing the picture. After the plate holder
with the negative has been placed into the box A, the door B is closed and the hands
and arms are pushed through the arm-holes G G. As already stated, the flaps a, b, c, d,
close up tight round the arms so as to exclude the light and at the same time sufficient
freedom of motion is allowed to the hands so that the negative can be readily removed
from the plate-holder and subjected to the necessary treatment for developing the
picture while being enclosed in the box A. The glass panes C, D, D¹ admit sufficient
light into the box so that the progress of the developing process can be observed, and
since it is sometimes difficult to follow this process through a red colored glass pane,
I have inserted into the top of the box the orange colored glass pane D which
however is protected by the screen E as stated, so that rays of light passing through
this pane into the box A will not injure the negative while by means of these rays,
the progress of the developing process can be clearly observed.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :
1. The combination with the box A, having a door B, panes C, D of non-actinic
colored glass and arm holes G G, of the elastically supported flaps a, b, c, d, sub-
stantially as described.
2. The box A having a red colored glass pane C and orange colored glass pane D
a screen E protecting the orange colored pane, arm-holes G G and elastically supported
flaps for closing said arm-holes, substantially as described.
Deted this Twantu cavanth day of Monch 1000