Improvements relating to what are known as Science Lanterns.
Year: 1893

page_text: Date of Application, 11th Sept., 1893
Complete Specification Left, 11th June, 1894-Accepted, 14th July, 1894
PROVISIONAL SPECIFICATION.
Improvements relating to what are known as Science Lanterns.
I HERBERT CHARLES NEWTON Scientific Instrument Maker, of 3 Fleet
Street, London E.C. do hereby declare the nature of this invention to be as
follows:-
The object of this invention is to render this class of lanterns more useful than
heretofore that is to say to enable the same lantern to be used for various purposes
and to improve the results that are obtained.
In carrying out my invention I arrange the two halves of the condenser in
separate frames hinged together in such a manner that they may be brought close
together or set at right angles to one another for purposes now well known.
To the frame of the outer half and at one corner thereof I adapt a rack rod and on
this rod I mount a sleeve which carries the focussing lens and which is arranged to
be racked in or out upon the rod in any convenient manner to obtain the proper
focus.
To the focussing lens tube I adapt another tube or a holder in which a prism is
mounted. This prism is silvered on one face to act as a mirror and it is mounted
on pivots which project through curved slots in the holder and may be provided
with clamping screws or nuts.
This prism may be used either for total reflection or as an erecting prism as may
be desired by loosening the clamping screws, turning the prism in the direction
required and bringing the pivots to the opposite end of the slots when they are
again clamped.
Suitable openings are made in the holder to permit of the passage of the rays of
light in the direction required and the one prism thus mounted answers all the
purposes for which two prisms are usually employed.
By means of the arrangements above described the instruments may be used for
both horizontal and vertical projections without necessitating any more lenses than
are required for ordinary direct lantern work thus saving the extra condensing and
focussing lenses which other systems require; many difficulties which are well
known to lecturers or demonstrators are entirely overcome and improved results
are also obtained.
Dated this 11th day of September 1893.
NEWTON & SON,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements relating to what are known as Science Lanterns.
I HERBERT CHARLES NEWTON Scientific Instrument Maker of 3 Fleet
Street London E.C. 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 :-
The object of this invention is to render this class of lanterns more useful than
heretofore, that is to say, to enable the same lantern to be used for various purposes,
and to improve the results that are obtained.

page_text: separate frames hinged together in such a manner that they may be brought close
together, or set at right angles to one another, for purposes now well known.
To the frame of the outer half, and preferably at one corner thereof, I adapt a
rack rod, or other suitable support, and on this rod I mount a sleeve which carries
the focussing lens, and which is arranged to be racked in or out upon the rod in
any convenient manner, to obtain the proper focus.
To the focussing lens tube I adapt another tube, or a holder, in which a prism is
mounted on pivots which project through slots in the holder. This prism may be
used either for total reflection, or as an erecting prism, as may be desired, by
turning the prism in the direction required, and bringing the pivots to the opposite
end of the slots.
In the accompanying drawing,
Fig. 1 is a side elevation of the improved lantern, and
Fig. 2 is a front view of the lens tube, looking from the right hand side.
A is the body of the lantern, in a tube in which, is fixed one half of the
condenser B. The other half B¹ is mounted in a frame C, which is hinged at its
upper edge to the lautern A.
To a corner of this frame, or in any other convenient position, is fixed the rack or
other rod D, upon which the front or focussing lens tube E is mounted so that it
can be worked in or out for adjustment.
The space between the condenser and the front lens is left quite clear, for
projecting apparatus, etc.
In front of the lens tube is secured a rectangular frame or holder F, in which a
prism G is mounted. This prism, which is silvered on one face, to act as a mirror,
is secured in a metal frame provided with pivots which project through shaped
slots in the sides of the holder F.
The slots are formed with a straight portion and a curved portion, and when the
prism is required for horizontal projection, the pivots will be in the end of the
curved portion, with the apex of the prism upwards, as indicated in the drawn
position of the apparatus, Fig. 1.
When vertical projection is required, the apparatus is caused to assume the
dotted position, Fig. 1, being supported in that position by a mirror H, and the
pivots are brought to the end of the straight part of the slots, the prism being turned
into the position as indicated.
The pivots may be provided with clamping screws, or other means, whereby the
prism may be fixed in either position.
The underside or front (according to the position) of the holder F, is removed, so
as to permit of the passage of the rays of light in the direction required. One prism
thus mounted answers for all purposes for which two prisms are usually employed.
By means of the arrangements above described, it will be seen, the apparatus
may be used for both horizontal and vertical projections, without necessitating any
more lenses than are required for ordinary direct lantern work, thus saving the
extra condensing and focussing lenses which other systems require, and the lecturer
or demonstrator can pass rapidly and easily from one kind of projection to the
other.
Many other difficulties which are well known to lecturers or demonstrators, are
entirely overcome, and improved results are also obtained by means of the present
invention; for instance, the invertion of the image on the screen, when projecting,
is obviated by using the same prism to erect as is used as a reflector for vertical
projection, in which capacity it gives a far more perfect image than a mirror.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
1 claim is
1. A science lantern constructed and arranged substantially as and for the
purpose herein set forth.

page_text: 2. In a science lantern for vertical and horizontal projection, mounting a prism.
in a holder, placed in front of the focussing lens, by means of pivots working
in suitably shaped slots in the holder, substantially as and for the purpose set
forth.
3. In a science lantern, mounting one half of the condenser in a frame hinged to
the body, and carrying, by means of a rack or other rod secured thereto, the
focussing lens tube and a prism holder, as set forth.
Dated this 7th day of June 1894
NEWTON & SON,
Agents for the Applicant.