A NEW OPTICAL INSTRUMENT FOR PRODUCING DESIGNS FOR ART MANUFACTURES AND OTHER PURPOSES
Year: 1873

page_text: LETTERS PATENT to Osgood Pritchard, of 55, Old Broad Street, in the
City of London, Architect, for the Invention of "A NEW OPTICAL
INSTRUMENT FOR PRODUCING DESIGNS FOR ART MANUFACTURES AND OTHER
PURPOSES."
Scaled the 14th October 1873, and dated the 2nd July 1873.
PROVISIONAL SPECIFICATION left by the said Osgood Pritchard at the
Office of the Commissioners of Patents, with his Petition, on the
2nd July 1873.
I, OSGOOD PRITCHARD, of 55, Old Broad Strect, in the City of London,
Architect, do hereby declare the nature of the said Invention for "A
NEW OPTICAL INSTRUMENT FOR PRODUCING DESINGS FOR ART MANUFACTURES AND
OTHER PURPOSES," to be as follows (that is to say) :—
My Invention has reference to the construction and employment of
an instrument or apparatus named the kaleidograph for producing and
displaying optical desings or effects in illuminated coloured devices or

page_text: patterns in infinite variety on a suitable ground, such as ground glass or
otherwise.
The principle of construction consists in the arrangement of the
front lenses at such an angle that the picture formed on the two
reflecting mirrors is caught up on the lenses and sent forward upon the
ground glass surface or otherwise aforesaid free from all dark shadows
or distortions, in this respect differing in principle from all hitherto
known instruments, inasmuch as the picture is perfected and carried
forward at an entirely different angle to the general line of the cylinder
containing the reflectors. The apparatus to be arranged in any portable
form, such as a rectangular box fitted with an argand, kerosene, or other
lamp behind the condenser, in close proximity to which is inserted a
slide with a revolving cell actuated by a ratchet movement, and con-
taining the various objects to be exhibited, immediately in front of
which slide is placed an horizontal cylinder containing two mirrors at
the proper angle, and silvered by Liebig's or other processes. At the
extremity of the plates or mirrors is adjusted a sliding tube containing
lenses placed at an angle to the cylinders reflecting the incident rays
formed by the slide upon the reflectors, and thereby throwing the
perfect picture upon the exhibiting glass at the angle aforesaid, the
picture thereby formed may be arrested or retained in position for the
purpose of being copied or photographed, which may be effected in full
daylight or by night.
In contradistinction to the common kaleidoscope whereby the pictures
formed can only be seen through a small aperture in the apparatus by
one person at a time, the designs produced by my Invention are not only
capable of being arrested at will as aforesaid for the purpose of being
copied, but owing to the employment of this angular reflecting tube in
connection with the rest of the apparatus the designs are thrown upon
a ground glass disk in front of the instrument so as to be seen by any
number of people at the same time perfectly illuminated and free from
distortion, thereby constituting the essential novelty and feature of my
Invention.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Osgood Pritchard in the Great Seal Patent Office
on the 1st January 1874,
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, OSGOOD
PRITCHARD, of 55, Old Broad Street, in the City of London, Architect,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of July, in the year of
our Lord One thousand eight hundred and seventy-three, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Osgood Pritchard, Her special licence
that I, the said Osgood Pritchard, my executors, administrators, and
assigns, or such others as I, the said Osgood Pritchard, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "A NEW OPTICAL
INSTRUMENT FOR PRODUCING DESIGNS FOR ART MANUFACTURES AND OTHER
PURPOSES," upon the condition (amongst others) that I, the said Osgood
Pritchard, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed in
the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Osgood Pritchard, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement, and the Drawings therein referred to (that is to
say):-
My Invention has reference to the construction and employment of
an instrument or apparatus named the kaleidograph for producing and
displaying optical designs or effects in illuminated coloured devices or
patterns in infinite variety upon a suitable ground, such as a disk or
plate of ground glass or otherwise, and consists in principle of con-
:

page_text: མིན་
struction in the arrangement, combination, and employment of the front
lenses at such an angle that the picture formed on the two reflecting
mirrors is caught up on the said lenses and sent forward upon the
ground glass surface, or otherwise aforesaid, free from all dark shadows
or distortions, in this respect differing in principle from all hitherto 5
known design producing optical instruments, inasmuch as the picture
is perfected by being carried forward at an entirely different angle to
the general line of the cylinder containing the reflectors.
And in order that my said Invention may be more fully understood
and readily carried into effect, I now proceed to describe the same by 1
aid of the accompanying Drawings, reference being had to the letters
and figures thereon marked (that is to say) :-
Fig. 1 represents a front elevation of the kaleidograph, as above
described; Fig. 2, side elevation partly in section; Fig. 3, transverse
vertical section thereof taken through the dotted line 1, 1.
Fig. 4, top or plan view with case partly broken away for the purpose
of showing the interior.
Fig. 5, detached end view of cylinder containing the reflecting
mirrors.
Figs. 6 and 7, side, edge, and end views of mirrors separately shown,
and Fig. 8 disk or plate of ground glass.
In each Figure the same letters of reference denote similar corre-
sponding parts.
A, A, the kaleidograph or optical instrument; B, B, outer case or box
containing the same; C, C, lantern; D, D, argand, kerosene, or other
lamp for giving light to the instrument immediately behind the con-
densing lens E, E, as shown in the Drawings; F, F, slide fitted with
revolving glazed cell G, G, containing the objects G¹ to be exhibited;
Hand H', toothed wheel and pinion gear for giving rotary motion to
the revolving cell; I, I, crank handle turned by hand for shifting the
objects within the slide, and changing the picture when desired;
J, J, horizontal cylinder containing mirrors J¹ silvered on the upper
surface by Liebig's or other process; K, K, front glass to cylinder;
L, L, adjustable tube sliding upon the end of the horizontal cylinder
containing lenses placed at the proper angle for reflecting the incident
rays formed by the objects within the slide upon the reflectors, and
]

page_text: carrying the picture forward upon the exhibiting glass; M, M, double
convex lens aforesaid fitted within the sliding cap or adjustable tube at
an angle to the reflectors aforesaid; N, N, maniscus lens mounted
within range of the double convex, as shewn; O, O, ground glass disk
on which the picture or designs are displayed for exhibition, inspection,
copying, or otherwise; P, P, projecting flange or shield for screening
and giving effect to the picture when viewed by persons seated in front
of the instrument; Q, Q, telescope slide formed in the box or case for
enabling the requisite focus to be obtained; R, R, picture or pattern
formed on the exhibiting glass in infinite variety.
In further describing the leading features of my said Invention it
may be here necessary to remark that in contradistinction to the
common kaleidoscope in which the picture formed can only be seen
through a small aperture in the apparatus by one person at a time, the
designs produced by my Invention are not only capable of being arrested
at will for the object of being copied, but by the entirely novel con-
struction and employment of the sliding cap or tube with its angular
arrangement of lenses, the designs or pictures are thrown upon the
ground glass so as to be seen by any number of people at the same time,
perfectly illuminated and free from distortions and shadows.
In conclusion to the foregoing description, I will here briefly note.
that the apparatus above described may be arranged in any other
portable form, or employed with or without the external box or case,
and supplied with an oxyhydrogen or other light in place of the kerosene
or argand lamp aforesaid.
And I would further note that I cause the light of the lamp or
otherwise to be placed immediately behind the condensing lens in close
proximity to the object slide, in front of which the horizontal cylinder
containing the reflecting mirrors is also arranged with its sliding cap
and lenses placed at the requisite angle for reflecting the incident rays
formed by the slide upon the exhibiting glass.
Having now fully described and ascertained the nature of this my
said Invention, and the manner in which the same is to be performed
and carried into effect, I would have it clearly understood that I do not
by any means intend to confine myself to the precise details herein-
before set forth and described, as the same may be otherwise varied
without departing from the general principle of this my said Invention,

page_text: nor do I claim as new and of my said Invention the exclusive use of the
several parts, combinations, and arrangement herein-before described
and set forth, except when the same are employed in and for the
purposes of my said Invention, which I hereby declare to consist in the
exclusive right of manufacturing and employing design producing
optical instruments upon the above principle of construction, having in
combination the horizontal cylinder, sliding cap, angular adjustment of
lenses, and the position of the lamp and revolving slide for reflecting
designs or pictures forward upon the ground glass disk out of or in the
direct line of the cylinder in the manner and for the purposes herein-
before set forth and described.
Witness,
B. F. WEATHERDON,
Law Chambers,
Chancery Lane.
OSGOOD PRITCHARD. (L.S.)