A New or Improved Device for Producing an Optical Illusion.
Year: 1896

page_text: Date of Application, 6th May, 1896
Complete Specification Left, 13th June, 1896-Accepted, 4th July, 1896
PROVISIONAL SPECIFICATION.
A New or Improved Device for Producing an Optical Illusion.
I, ERNEST PRENTICE, Auctioneer, of 64, Orford Street, Ipswich, in the
County of Suffolk, do hereby declare the nature of this invention to be as
follows:-
My invention consists of a simple device constructed on the principle of the
absorption spectrum, and has for its object to produce an amusing optical illusion
in the nature of an imitation of the photographs of the human hand and such like
objects obtained by the now well-known "Röntgen rays," wherein the flesh
appears transparent and the bones of the fingers are plainly visible.
For this purpose between two small discs or pieces of glass or other transparent
material I place a selected portion of the vanes or barbs of a feather or equivalent
light-absorbing medium. If a feather is used the part chosen should be of the
closest, finest, and most transparent texture. The feather and glasses are mounted
in a sight aperture in a holder of any convenient kind.
On looking through the aperture when held between the eye and the hand or
object against a fairly strong light the optical illusion is produced and is in effect
similar to that of the photographs above referred to.
Dated this 6th day of May 1896.
J. C. CHAPMAN,
Agent.
A New or Improved Device for Producing an
I, ERNEST PRENTICE, Auctioneer, of 64, Orford Street, Ipswich, in the
County of Suffolk, 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:-
My invention cousists of a simple device 'constructed on the principle of the
absorption spectrum, and has for its object to produce an amusing optical illusion
in the nature of an imitation of the photographs of the human hand and such like
objects obtained by the now well-known "Röntgen rays," wherein the flesh
appears transparent and the bones of the fingers are plainly visible.
For this purpose I use a selected portion of the vanes or barbs of a feather or
equivalent light-absorbing medium in combination with a casing or holder of
suitable kind and preferably one or two pieces of glass, mica, or other transparent
material. The glass is not actually necessary to the illusion, but it is advantageous
in protecting the feather from injury. The part of the feather chosen should be
of the closest, finest, and most transparent texture.
Referring to the drawing,
Fig. 1 is an elevation of the device, the feather being enclosed in a box or
camera-shaped case;
Fig. 2 is a section on line 1-2; and Fig. 3 is a longitudinal section of Fig. 1.
Fig. 4 illustrates partly in elevation and partly in section the feather mounted
in a cylindrical casing.

page_text: Fig. 5 shows a cheaper form of construction, the feather being mounted in a
plain holder, Fig. 6 is a central cross-section thereof, and Fig. 7 shows details of
this construction.
In Figs. 1, 2 and 3, F is a selected portion of feather mounted between coinci-
dent holes a a cut in supporting plates A. A of millboard, wood, or the like.
These are fitted into an outer box-like case C having sight aperture S shown
flared outwardly, and an object aperture O. G is a sheet of glass placed in any
convenient position and serving to prevent insertion of the finger or a tool which
might injure the feather. To increase the delusion the plates A A may be
provided with side knobs K working in slots k to simulate that adjustment or
focussing may be desirable.
In Fig. 4 the case is shown of cylindrical form, the same letters referring to
same parts. In the simple form shown in Figs. 5, 6 and 7, the portion of feather
is held between two discs of glass or equivalent g g placed in the depressions d d in
two millboard stampings A A forming the holder between the sight holes S S
therein, and the two parts A. A are then glued together.
On looking through the sight aperture S when the toy is held between the eye
and the hand or object to be examined against a fairly strong light the optical
illusion is produced, and is in effect similar to that of the photographs above
referred to.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The use for producing the optical illusion above referred to of a portion of
feather or equivalent light absorbing medium mounted in a casing or holder with
sight holes, substantially as set forth.
2. The combination with the portion of feather F suitably supported, of an
enclosing casing C with sight and object holes, substantially as and for the purpose
set forth.
3. The combination with the portion of feather F of two transparent pieces of
glass or equivalent transparent material 9 g and holder A with sight aperture,
substantially as described and shown.
Dated this 13th day of June 1896.