An Instrument or Toy that Makes Objects Seen Through it Appear Greatly Decreased in Height and Increased in Breadth, or Conversely.
Year: 1889

page_text: Date of Application, 21st May, 1889
Complete Specification Left, 20th Feb., 1890-Accepted. 29th Mar 1890
PROVISIONAL SPECIFICATION.
An Instrument or Toy that Makes Objects Seen Through it Appear
Greatly Decreased in Height and Increased in Breadth, or
Conversely.
I JOHN ANDERTON 142 Suffolk Street (Scientific Instrument Maker) Birmingham
do hereby declare the nature of this invention to be as follows :-
:-
A prism of glass cut to about an angle of forty degrees is placed apex downwards
before the eye or eyes: immediately behind this a second prism of somewhat similar
angle is placed with its base downwards. If these two prisms be parallel, objects
appear through them as if seen through plain glass, but if either or both prisms be
inclined towards or from each other, objects seen through them appear grotesquely
altered.
For example-If prism placed nearest the eye be stationary, and the second prism
be turned so that its apex approach the base of eye prism, objects seen through them
appear of decreased height and increased breadth, and this effect increases as second
prism is further and further inclined.
If the apex of second prism be turned in opposite direction, that is away from base
of first prism, the converse effect is seen, the objects then appearing greatly elongated
and lessened in breadth.
Other grotesque effects are produced by the combination of the two prisms, and
when they are fixed in proper position, by moving the two together, objects are made
to appear to change their proportions &c.. The two prisms can also be cut to a double
angle. If these prisms be placed with their bases inclined to each other, and the eye
placed near the top, objects seen through them appear elongated and lessened in
breadth, if the eye be moved to the bottom the converse is seen, the change being
instantaneous, and this without either prism being moved.
Dated this 20th day of Mar 1980
JOHN ANDERTON.
COMPLETE SPECIFICATION.
An Instrument or Toy that Makes Objects Seen Through it Appear
Greatly Decreased in Height and Increased in Breadth, or
Conversely.
I JOHN ANDERTON of 142 Suffolk Street Birmingham in the county of Warwick
Scientific Instrument maker, 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, reference being had to the accompanying drawings
and to the letters and Figures marked thereon :-
This invention consists of a prism of glass cut to an angle of 40° which prism is
placed with its base upwards. Behind this a second prism of a somewhat similar angle
is placed in the reverse position i.e. with its base downwards. If the bases of these
prisms so placed be parallel, objects seen through them appear of true size, and
proportions but if either one or both of the prisms be inclined so that their bases
are no longer parallel to each other objects seen through them appear grotesquely
altered.
For example-If the first prism that is the one nearest to the eye of the observer
be fixed and the second prism be moved so that its apex approaches to and its base
recedes from the first prism objects seen through them appear of decreased height and
ncreased breadth the former effect increasing as the second prism is further inclined
n the direction indicated.

page_text: Referring to the accompanying drawings which shew a side view of the prisms in
one position. (A) is the prism placed with its base upwards this prism being nearest
to the eye of the observer and (B) is the second prism placed base downwards and
inclined as shewn..
Let (D) represent the position of the eye of the observer from one point of :
observation.
When the second prism (B) is moved in the opposite direction i.e. when its apex
recedes from and its base approaches the first prism the converse effect is seen, objects
seen through them appearing elongated and reduced in width.
If the second prism (B) be turned whilst objects are seen through them the latter
can be made to appear either of true size and proportions or of increased height and
lessened breadth or of decreased height and increased breadth according to the
direction in which the prism is turned. When the prisms are placed to shew objects
of diminished height and increased breadth as shewn if the eye be placed at (C) objects
are seen elongated and decreased in width.
The prisms can be cut to double angles and so placed that objects viewed through
one angle appear the converse of what they seem when viewed through another. The
effects mentioned are produced without aberration or chromatic dispersion the one
prism correcting the dispersion, chromatic and otherwise of the other.
The prisms may be fitted in any suitable case the same being pierced for the eye or
eyes of the observer to see through.
Reference has been made to one pair of prisms only as used in the single or one
eye instrument.
In that in which both eyes are used two pairs of prisms are necessary
or the prisms must be of sufficient length to reach from eye to eye.
The combination of the prisms and their angles can be varied.
The instrument or toy can be used in combination with a camera for taking
grotesque photographs or it can be used with a magic lantern and also with an opera
glass or telescope.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is.
•
First. The use of an instrument or toy constructed with prisms of glass and thereby
making objects seen through them appear greatly decreased in height and increased
in breadth or conversely.
Second. I claim the instrument or toy as made by my method as applied to a
camera, magic lantern telescope, opera glass and such like articles and for the purposes
herein set forth.
Third. I claim the use of prisms of glass generally as applied to toys and instruments
whereby any of the effects herein before mentioned are produced, substantially as
herein set forth.
Dated this 19th day of February 1890
EDWARD J. PAYNE & SON,
104, Colmore Row, Birmingham, Agents for the Applicant.