A NEW OR IMPROVED SYSTEM OF STEREO- SCOPIC APPARATUS
Year: 1872

page_text: PROVISIONAL SPECIFICATION left by William Edward Gedge at the
Office of the Commissioners of Patents, with his Petition, on the
4th October 1872.-A communication from abroad by Charles
Fayel, M.D., of No. 64, Faubourg St. Martin, Paris, France.
I, WILLIAM EDWARD GEDGE, of No. 11, Wellington Street, Strand,
in the County of Middlesex, Patent Agent, do hereby declare the
nature of the said Invention for "A NEW OR IMPROVED SYSTEM OF STEREO-
SCOPIC APPARATUS," a communication to me from abroad by Charles
Fayel, M.D., of No. 64, Faubourg St. Martin, Paris, France, to be as
follows:-
In its present state the stereoscope is essentially composed of a
chain winding upon a crank worked by two exterior knobs; to this
chain are riveted frames intended to support the stereoscopic cards,
their number varying at the pleasure of the maker. The box enclosing
this apparatus is furnished in front with two eye-glasses through which
the spectator contemplates the photographs. A glass at the back
permits the introduction of light. The top is divided into two hinged
parts, one of which furnished with a rack and a reflecting glass assists
in lighting up the pictures.
Suppose 50 photographs filling the 50 frames of an apparatus thus
composed, the hand turning the knob brings in turn and successively

page_text: the 50 proofs before the eyes applied to the two eye-glasses. If the
apparatus has 100 or 200 frames, 100 or 200 views will succeed each
other, but at the 50th or the 100th the circle will be closed and the
first photograph will reappear.
The improvement, the subject of this Invention, consists in doubling
the number of stereoscopic cards in any kind of apparatus, and that
without increase of cost if an entirely new apparatus be constructed
and at a cost of two or three shillings for the alteration of an old one.
By this improvement a 50 view stereoscope receives 100 views, and
one of 200 receives 400, as I will now explain.
.
Operative Process.-Taking for example an ordinary stereoscope with
any number of frames. The box is sawn horizontally at about half an
inch below the unpolished or ground glass facing the eye-glasses.
This cut made also in front passes at about 2 inches from these same
eye-glasses, and stops at the sides about half way from the angles of
the box and the outside knobs. There from horizontal it becomes
vertical for about from 2 to 3 inches, then each of these vertical
sections are joined by a horizontal saw stroke passing at from ½ an
inch to 1 inch above the two knobs of the crank. These knobs or studs
therefore remain upon the lower part of the box when the section is
completed. The box is thus divided into two parts, the upper one cut
straight front and back, and cut sloping equally on the two sides (I
have represented and described this limited sloping cut by straight lines,
it will however be evident that it may be by curved lines, more or less
arched and passing above the knobs), the lower part also cut straight
front and back, and presenting on the sides a median projection corre-
sponding very exactly with the above mentioned. It is to this median
or middle part that the two knobs of the crank and consequently all
the working apparatus of the stereoscope remain adhering, while to the
upper portion there remain the various parts necessary to the vision.
Nothing is more simple than sawing the box, but to hide this little
work and above all to ensure contact of the two parts thus separated,
a rebate of about ½ an inch is applied all round the upper segment in
such wise that the whole may remain or become again immovable when
it is replaced on the lower segment. Any cabinet maker will easily
perform this work.
Instead of thus transforming an old apparatus this process of cutting
out or that herein-after described may be applied to the construction of

page_text: a new box, and the object of this Invention is at once attained. In fact
all that is now required in order to double the number of stereoscopic
cards without changing the essential parts constituting the actual
apparatus, is simply to place back to back in each frame two views
instead of one. When the rotary movement of the knobs has brought
before the eyes the 50, 100, or 200 views as in ordinary stereoscopes,
remove the cap or cut top of the box, turn the front to the back, replace
it again, and there are 50, 100, or 200 new views to be examined.
The accompanying Sheet of Drawing shows the stereoscope with cut
top or cap with its rebate in position, and, the box with cap removed
and placed at the side. The Drawing also shows the ends of the two
cards placed back to back in each frame.
Such is this Invention, but there are other modes of realising it. I
will give one only, namely, instead of sawing the box into two unequal
parts, the upper one of which includes the eye-glasses, and the ground
glass which at the will of the spectator may be placed back or front,
remove by a perpendicular stroke of the saw the portion of wood which
supports the eye-glasses and the ground glass which a second horizontal
cut completely separates from the apparatus, and apply on each side a
small groove adhering to the lower part and in which will slide the two
boards cut perfectly equal; then instead of the single glass actually
applied upon the flap of the cover above the eye-glasses put a second on
the opposite flap which will also be provided with a second rack, and
you can then by removing the two boards from their slides put the one
in the place of the other, and as in the preceding case have a new series
of stereoscopic views to examine.
I need scarcely observe that this latter construction can be also
adopted in the manufacture of new boxes, in which case even the cost
of a second glass to the flap might be avoided by leaving each of the
flaps of the cover adhering by its actual hinges (which if needed may
be brought closer to each other) to the two boards which play in the
two lateral slides.