Improvements in Optical Lantern Stages, Slide Carriers, and Slides for Registration.
Year: 1890

page_text: Cate of Application, 17th Dec., 1890
Complete Specification Left, 15th Sept., 1891-Accepted, 31st Oct.,
1891
PROVISIONAL SPECIFICATION.
Improvements in Optical Lantern Stages, Slide Carriers, and Slides
for Registration.
1, DAVID LIONEL SALOMONS Baronet, of Broomhill Tunbridge Wells Kent,
do hereby declare the nature of this invention to be as follows :-
Firstly in respect to the adjustinent of the stage runners or slide carriers of the
optical (or magic) lantern:
Since slides which require registration by means of stops fixed to their edges abut
against the end of the runner of the stage, it becomes necessary to fix the said stops
most accurately and the abutment stops which are attached to the end of the stage
for use with those slides which are pushed through the stage until they reach such
stop to ensure their correct position for registration, must have a definite position or
the slides which have stops affixed to them will not register correctly. The
necessity of working to the two fixed points (iz. the end of the runner & the non-
adjusting side stop) is found to be most inconvenient & often detrimental to an
exhibition upon a screen.
At the present time it is usual to make the side stops just referred to adjustable
& capable of being clamped, and I now propose to make the end of the runner or
end of any form of carrier adjustable.
This part of my invention I achieve by moving the runner bodily to or fro by
means of screw & locking it with a lock nut, or by moving to & fro by means of
wedges, screws, racks, or any of the well known mechanical methods any portion
of the runner or the whole runner as before named so as to lengthen & shorten at
pleasure within the required limits the distance between the end of the stage unner
against which the stopped slides abut & the stop or point of registration for ordinary
slides. The same treatment can be applied to carriers.
This improvement enables the discs to be registered in the best way by means of
standard registering slides, when all picture & other slides which have been set or
cut to register will register correctly on the screen.
As it does not follow that slides which have affixed to them abutment stops will
afterwards register correctly (even though they have been registered in the first
instance) since when registering anew with the standard registering slides, the
optic axis of the system of lenses may not pass through the same part of such
slides which abut against the stop fixed to the stage, as when these slides were first
registered and consequently also not through the same part of those slides to which
stops were attached when registered with them, or in the lantern stages set truly
in register by their aid in the first instance.
With the improvement here proposed it will only be necessary to alter the
length of the stage runner or carrier to a slight extent or move it bodily, for the
original distance to be reestablished at any time, after the frames may have altered
through expansion or contraction, & once more obtain the register without any
further trouble.
In order to facilitate the correct registration of slides & to throw the discs
from two or more lanterns coincidently and to the best advantage upon a
screen, I propose the use of a number of standard slides, one to be placed in
each lantern; & since these are all mathematically alike, or so far as present
means exist for making them so, it is evident that to all intents & purposes
the figures upon 2 or 3 of such slides may be made to superimpose upon the
screen so as to appear to the eye as if only one slide of the figure had been
projected. To bring the coincidence about well made optical lanterns should
have suitable adjustments and some have, but till now there have been no

page_text: standard registering slides made which can be depended upon for truth &
accuracy, and since this class of slides is used uot only for adjusting the lantern
before an exhibition but to set & cut the ordinary slides by the importance of having
such standard slides of a character to be depended on for accuracy at all times &
in all climates is clear.
The second part of my invention consists of improvements in such standard
registering slides. In describing them let it be understood that in every form to
be hereafter described, the part of the slide which rests upon the runner must be
true, so also is the end which abuts against the stop fixed to the end of the stage,
& these two true edges or surfaces must be at right angles to one another. The
word "true" is used in the usual engineering sense as applied to flat surfaces in
rectangular forms. In all cases it is proposed to make the working part of the
slide of glass, and it is also proposed to make the slides about the usual size of
frame slides in England, although they can be made in any size if desired. It is
further intended that the figures on the slides shall be as follows:
A horizontal line so placed that when projected, the disc shall be approximately
divided into an upper & lower half, a vertical line so placed that when projected
the disc shall be divided into a right & left handed half, the combined effect
of these two lines being a projected disc divided into quadrants. Besides these
lines there are to be four more, symmetrically placed about those just mentioned
forming a square with its sides parallel with one or other of the lines dividing
the disc into a quadrant, but not so large as to occupy the whole disc, each
angle of the said square might occupy the center of each quadrant.
Other figures would answer the purpose but the figure referred to is the best for
the purpose.
Having so far described the slides generally in respect to their common properties,
I-will-proceed to describe in detail some of the most suitable forms when ready
for-use...
The simplest form would be a slab of glass trued on-two-edges as mentioned,
with the figure described upon it at the proper place. Three such glasses
would be required for a triple lantern, two for a bi-unial lantern. All slides
that are used as a set or to form sets of identical make must by preference
-have-the lines_put on them at the same time, in any suitable dividing engine
or with any machine capable of doing dividing-and-such-a-class_of_work, for
instance a milling machine, lathe, planing machine, since many such machines can
be arranged to accomplish-dividing work. The lines are preferably etched on the
glass, or the lines may be engraved on the glass by any other suitable means.
In the place of glass, metal plates may be used with figures or lines perforated
in them. In the case of lines when their position would cause a part of the
plate to fall out, small portions of the plate could be left here & there as is
done with stencil plates. Glass slides as described could have the sides protected
with wood or other suitable material a hole being cut at suitable places for the
light to pass through.
Another form of slide is to have a metal frame trued as mentioned with the
etched glass mounted within it, & if desired glasses placed over each side of
the etched or engraved glass to act-as-a-protection.
In this form of frame it is necessary to etch or engrave the glass after
mounting in the frame from which it must not be removed after the operation.
The best method of fixing the glass in the metal frame is to press it against the
two sides which have been trued on the outside edges.
This may be done by means of screws pressing upon the opposite edges of the
glass, these screws passing through the frame. Also these screws should not press
upon the glass direct or it may be broken when the glass or metal becomes expanded
by heat or if the slide is jarred A piece of ivory or well seasoned wood should
he inserted between these holding screws & the glass.
The ivory or wood may also be shaped in a way to act spring fashion.
Another &-probably better way of holding the glass in place is to cut a corner

page_text: off the glass opposite to the side of the frame which has been made a right angle,
& here to place a small ivory ring pressed against the glass by means of a screw
passing through the corner of the metal frame.
The glass must be kept from falling out by means of any of the usual methods so
as to be equivalent to having placed it in a groove, either such a groove from the
first or one built up.
The protecting glasses, if used should not be in contact with the one which
is engraved or etched. There are an unlimited number of ways in which the metal
frames may be made such as cast solid, built up, built up to have half the groove
in each balf, or half a V groove in one half & no part of a groove in the other
half. In the last case the glass will rest in the half V groove; or the glass may
be mounted as previously described & protecting glasses resting on or in a metal
cell that shall prevent the etched glass being in contact with the protecting ones
& hence not possible to be shifted on being touched or the outside glasses being wiped.
The metal frame mounted slides have the advantage that another very important
registering piece can be added with great facility. To the end opposite the one
trued, which abuts against the stage stop, a bracket can & should be attached by
being screwed on, and this bracket must project below the lower & trued edge of
the slide, say to the extent of of an inch. This projecting part of the bracket
may be recessed if need be so as not to prevent the slide being pushed into the stage
a little beyond its end. This bracket to have a screw & lock nut at the part which
projects, so that this screw may abut against the end of the stage runner, & the
point of abutment can be varied by means of the screw & which may be fixed with
the lock nut. Thus registration can be effected by means of the slide adjusting
stop picces as well as by means of the stage stops, giving in this way two methods
of registration as well as the combined metho's which would be used when
registering slides requiring stops to be affixed to them, with slides which register
by abutment against the stage stops.
Datad this Thirteenth day of Dagambar 1800
COMPLETE SPECIFICATION.
Improvements in Optical Lantern Stages, Slide Carriers, and Slides
for Registration.
1 DAVID LIONEL SALOMONS Baronet, of Broomhill Tunbridge Wells Kent,
do hereby declare the nature of this invention and in what manner the same is to he
performed, to be particularly described and ascertained in and by the following
statement:
Firstly in respect to the adjustment of the stage runners or slide carriers of
the optical (or magic) lantern since slides which require registration by means
of stops fixed to their edges A. Fig. 1abut against the end of the runner B
Fig. 1. of the stage C it becomes necessary to fix the said stops most accurately
& the abutment stop: D which are attached to the end of the stage C for use
with those slides which are pushed through the stage until they reach such stop
to ensure their correct position for registration must have a definite position or
the slides which have stops affixed to them will not register correctly. The
necessity of working to the two fixed points (oz. the end of the runners B&
the non adjusting side stop D') is found to be most inconvenient and often
detrimental to an exhibition upon a screen. At the present time it is usual to
make the side stops just refered to adjustable & capable of being clamped-and
I now propose to make the end of the runner E or end of any form of carrier
adjustable. This part of my invention I achieve by moving the runner E, E'
bodily to & fro by means of a screw or screws & locking it with a lock nut or set
screw or by moving to or fro by means of wedges, screws, rack or any of the well
known mechanical methods any portion of the runner E E¹ or the whole runner as

page_text: before named so as to lengthen & shorten at pleasure within the required limits the
distance between the end of the stage runner E against which the stopped slides
abut at E & the stop or point of registration for ordinary slides at F. The same
treatment can be applied to carriers. This improvement enables the discs to be
registered in the best way by means of standard registering slides when all pictures
& other slides which have been set or cut to register will register correctly on the
screen, as it does not follow that slides which have affixed to them abutment stops
will afterwards register correctly (even though they have been registered in the
first instance) since when registered anew with the standard registering slides the
optic axis of the system of lenses may not pass through the same part of such
slides which abut against the stop fixed to the stage as when these slides were first
registered and consequently also not through the same part of those slides to which
stops where attached when registered with them, or in the lantern stage set truly
in register by their aid in the first instance.
With the improvement. here proposed it will only be necessary to alter the length
of the slide runner to a slight extent or move it bodily for the original distance to
be re-established at any time after the frames may have altered through expansion
or contraction & once more obtain the register without further trouble. In order
to facilitate the correct registration of slides & to throw the discs from two or more
lanterns coincidently and to the best advantage upon a screen I propose the use of
a number of standard slides, one to be placed in each lantern; and since these are
all mathematically alike or so far as present means exist for making them so, it is
evident that to all intents & purposes the figures upon 2 or 3 of such slides may be
made to superimpose upon the screen so as to appear to the eye as if only one of
the figures had been projected. To bring the coincidence about well made-optical
lanterns should have suitable adjustments and some have, but till now there have
been-no-standard.registering slides made which can be depended upon for truth &
accuracy, and since this class of slide is used not only for adjusting-the-lantern
before an exhibition but to set & cut ordinary-slides by, the importance-of-having-
such standard slides of a character to be depended on for accuracy at all times
& in all climates is clear.
33
The second part of my invention consists of improvements in such standard
-registering.slides Fig. 3. In describing them let it be understood that in every
form to be hereafter described, the part of the slide which rests-upon-the-runner
must be true so also the end which abuts against the stop fixed to the end of the
stage & these two trned edges or surfaces-must-bcat_right angles to one another.
The word "true is used in the usual engineering sense as applied to flat surfaces
in rectangular forms. In all cases it is proposed to make the working part of glass
and it is also proposed to make the slides about the usual size of framed slides in
England altho' they can be made in any size if desired. It is further intended that
the figure upon the slides shall be as follows:-A horizontal line so. placed that
when projected the disc shall be approximately divided into an upper & lower half,
a vertical line so placed that when projected the disc shall be divided into a right
& left handed half, the combined effect of these two lines being a projected disc
divided into quadrants. Besides these lines there are to be four more symmetrically
placed about those just mentioned forming a-square-with-its-sides parallel with one
or other of the lines dividing the disc into a quadrant, but not so large as to occupy
the whole disc. Other figures would answer the purpose but the figure refered to
is the best for the purpose see Fig. 3.
Having so far described the slides generally in respect to their common properties
I will proceed to describe in detail some of the most suitable forms when ready for
use. The simplest form would be a slab of glass trued on two edges as mentioned
with the figure described upon it at the proper place.
Three such glasses would be required in a triple or tri-unial lantern and two
for a bi-unial lantern. All slides that are used as a set or to form sets of identical
make must by preference have the lines put upon them at the same time in any
suitable dividing engine or with.any machine capable of doing dividing & such class

page_text: of work, for intance a milling machine, lathe, planing machine, since many such
machines can be arranged to accomplish dividing work. The lines are preferably
etched on the glass, or the lines may be engraved on the glass by any other suitable
means. In the place of glass metal plates may be used with figures or lines
perforated in them. In the case of lines when their position would cause a part of
the plate to fall out small portions of the plate could be left here & there as is
done with stencil plates.. Glass slides as described could have the slides protected
with wood or other suitable material a hole being cut at suitable places for the
light to pass through. Another form of slide is to have a metal frame trued as
mentioned with the etched glass, mounted within it and if desired glasses placed
over each side of the etched or engraved glass to act as a protection.
In this form of frame it is necessary to etch or engrave the glass after mounting
in the frame from which it must not be removed after the operation. The best
method of fixing the glass in the metal frame is to press it against the two sides
which have been trued on the outside edges. This may be done by means of
screws pressing upon the opposite edges of the glass, these screws passing through
the frame. Also these screws should not press upon the glass direct or it may be
broken when the glass or metal becomes expanded by heat or if the slide is jarred.
A piece of ivory G. or. well seasoned wood should be inserted between these
holding screws and the glass. The ivory or wood may also be shaped in a way to
act spring fashion. Another & probably a better way of holding the glass in place
is to cut a corner off the glass opposite to the side of the frame which has been
made a right angle & here to place a small ivory ring pressed against the glass by
means of a screw passing through the corner of the metal frame. The glass must
be kept from falling out by means of any of the usual methods so as to be
equivalent to having placed it in a groove, either such a groove from the first or
one built up. The protecting glasses if used should not be in contact with the one
which is engraved or etched. There are an unlimited number of ways in which
the metal frames may be made, such as cast solid, built up, built up to have half
the groove in each half, or half a V groove in one half & no part of a groove
in the other. In the latter case the glass may be mounted as previously described
& protecting glasses resting in a metal cell that shall prevent the etched glass
being in contact with the protecting glasses, & hence not possible to be shifted on
being touched, or on the outside glasses being wiped. The metal frame mounted
slides have the advantage that another very important registering piece H Fig. 3
can be added with great facility.
To the end opposite the one trued which abuts against the stage stop Fa
bracket H can & should be added by being screwed on and this bracket must
project below the lower & trued edge of the slide say to the extent of of an inch.
This projecting part of the bracket may be recessed if need be so as not to prevent
the slide being pushed into the lantern stage a little beyond its end. This bracket
to have a screw & lock nut at the part which projects so that this screw may abut.
against the end of the stage runner, & the point of abutment can be varied by
means of the screw & which may be fixed with the lock nut. Thus registration
can be effected by means of the slide adjusting stop pieces I as well as by
means of the stage stops F giving in this way two methods of registration as
well as the combined methods which would be used when registering slides
requiring stops to be affixed to them as at A with slides which register by
abutment against the stage stops F.
Having now particularly described and ascertained the nature of my said inven-
tion & in what manner the same is to be performed I declare that what I
claim is
1. An adjustment to lantern stage runner or slide carriers for the magic lantern
for ensuring superposition of similiar views or designs when projected from two
or more lanterns or optical systems attached to one or more bodies containing an

page_text: illuminant or illuminants such as generally known as optical lanterns, & constructed
substantially as described.
2. The movement attached to the standard registering slide by means of screw
& lock nut fastened to the bracket substantially as described.
3. The etched or engraved standard slides or designs on glass only or on glass
mounted in metal and trued substantially as described.
4. The combination of adjustable stage runners or slide carriers and etched or
divided standard slides by which perfect registration or coincidence of designs or
similiar views can be made at any time, substantially as described.
Dated this Fifteenth day of September 1891.
JAMES HENRY STEWARD,
Agent.