Improvements in Photochromostereoscopes, also applicable to Cameras:
Year: 1899

page_text: Date of Application, 24th Feb., 1899-Accepted, 18th Nov., 1899
COMPLETE SPECIFICATION.
Improvements in Photochromostereoscopes, also applicable to Cameras:
We, CHARLES SWIERS LUMLEY, of 14, Uverdale Road, Chelsea, in the County
of London, Cabinet Maker, ThoмAS KNIGHT BARNARD, of the Queen's Hotel,
Oswestry, in the County of Salop, Musician, and FREDERICK GOWENLOCK, of
Truro Villa, Potters Bar, in the County of Middlesex, Gentleman, do hereby.
declare the nature of this invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:-
This invention relates to improvements in photochromostereoscopes and is
also applicable to cameras and has for its object the arrangement and construc-
tion of such a device whereby the difficulties are overcome which have obtained in
instruments hitherto made, with regard to adjustment of the operative parts,
the prevention of double images on the mirrors, the multiplicity of images and
their correct superposition to secure perfect registration of the independent
images in the combined results and the general complex and difficult features of
construction. We obtain these objects, 1stly, by the reduction in the number
of superposed images from three to two thus avoiding the errors due to refrac-
tion and reflection in the optical devices, and 2ndly, by the great simplicity of the
construction of the device enabling the adjustments to be readily made so as to
produce a good result.
In instruments hitherto made the cost of manufacturing the transparent
mirrors has been very considerable, as it has been found necessary to work upon
both surfaces of the mirrors to obtain their correct form; this difficulty we
entirely-overcome.
The result obtained from our instrument depends upon the physical fact that
if one eye of an observer receives an image of one colour and the other eye a
similar image of another colour, the resultant effect on the brain is one image
of a colour formed of the combination of the two said colours.
In order that our invention may be the better understood we will now proceed
to describe the same in relation to the accompanying drawings reference being
had to the letters and figures marked thereon. Like letters refer to like parts
in the various figures.
Figure 1 is a side sectional elevation of our device.
Figure 2 is a plan of the same.
Figure 3 is a perspective view of the device for holding the transparent reflect-
ing mirrors.
Figure 4 is a plan of the same.
Figure 5 is a perspective view of the complete instrument.
Our device consists of a rectangular box A, one end B of which is hinged at C
and carries the two eye pieces or lenses D. The box is hinged at E to the base
board F and is provided with one or more adjusting stays G by means of which
the angle of the box A with the base board F can be adjusted as desired. At

page_text: the end of the box A opposite to the lenses a reflector H is hinged so as to be
adjusted angularly with regard to the box A, and rebates or grooves I are pro-
vided for holding one of the photographic monochrome positives J. An aper-
ture K is arranged in the top of the box A for receiving the second positive J,
beneath which is fixed one colour screen L say of a green colour. Immediately
behind the positive J we arrange two colour screens M and M¹, say, blue and red,
side by side, ie., the red screen M being behind one picture of the positive and
the blue screen M being behind the other picture of the positive. Within the
box A are situated the transparent mirrors N N¹ which are mounted on a base O
adapted to slide into the box A through the end B so as to be removable there-
from for the purposes of adjustment. A vertical partition P is supported on the
base to restrict the field of vision of each eye piece to its respective picture.
The mirrors N N are held at their lower edge by slotted clips Q which allow of
adjustment in the plane of the base, while on the under side centrally disposed
is a vertical rib R upon which they rest, the rib R being attached to the base
board so that the angle of the mirrors with the base board O can be adjusted
by means of a screw S adapted to raise or lower the left hand end of the support-
ing rib R. The mirrors are kept in place by means of a clip m and spiral
spring n attached to the rib R. Another adjusting screw T is provided in the end
of the base board which coacts with the internal surface of the box A to adjust
the mirrors N, N', longitudinally to the box A, a spring U being arranged on
the base to push the latter against the opposite side of the box A to ensure
automatic adjustment when inserting the mirrors and their support into the
box A. We also provide three adjusting screws V in the base O for adjusting
it relatively to the bottom of the box A for the adjustment of the mirrors in a
horizontal plane. A spring W is carried by the box A on each side of it, adapted
to press the base upon the bottom of the box A to maintain the mirrors in a
rigid position with the box.
We prefer to use transparent mirrors which are coloured, so that the rays of
light of each respective colour which fall upon the said mirrors are reflected
only to the eye-piece in a single image, for example the mirrors NN1 may be
blue and red respectively corresponding to the colour screens M and M. We
may in some cases do without the colour screens M M¹ and L and in substitution
therefor we use chromograms which have the gelatine or other films stained with
the necessary colour.
When using the device as a camera a dark slide or other device for holding
sensitive surfaces or elements is fitted to the box A at the two apertures con-
trolled by the screens M M and L and suitable photographic lenses are used on
the front in substitution of the eye pieces.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed we declare that what we
claim is:
1st. A photochromostercoscope or photochromostereoscopic camera_consisting
of a case having two apertures one of which is controlled by one colour screen
and the other by two colour screens so as to produce two sets of images represent-
ing distinct colour sensations upon and through a transparent mirror within the
case and two eye pieces or lenses for viewing the images or taking chromophoto-
graphic records, substantially as described.
2nd. In a device as claimed in Claim 1 the arrangement of the transparent
mirror or mirrors upon a detachable support adapted with means for adjustment
in three planes, substantially as described and illustrated in the accompanying
drawings.
3rd. The arrangement and construction of a photochromostereoscope or photo-
chromostereoscopic camera substantially as described and illustrated in the accom-
panying drawings.
4th. In a photochromostereoscone
or
photochromostercoscopic camera
the

page_text: arrangement of the colour screens of different colours on each side of the instru-
ment so that when the images of different colours produced by and shown in the
device are viewed by the two eyes of the observer the result is a single impression
of true gradation and colour value, substantially as described.
Dated this 24th day of February 1899.
FELL & JAMES,
1, Queen Victoria Street, London, E.C., Agents for the Applicants.