Improvements in Apparatus for Exhibiting Panoramic, Dissolving, or Changing Views, and in the Manufacture of Slides for Use therewith.
Year: 1893

page_text: Date of Application, 29th Nov., 1893
Complete Specification Left; 1st Oct., 1894-Accepted, 29th Nov., 1894'
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Exhibiting Panoramic, Dissolving,
or Changing Views, and in the Manufacture of Slides for Use
therewith.
I, WILLIAM FRIESE-GREENE of 39 King's Road, Chelsea, London, Photo-
grapher, do hereby declare the nature of this invention to be as follows:-
My invention relates to that class of apparatus which is adapted to throw, by
means of suitably arranged lenses, enlarged representations of photographic or
other transparent pictures upon a screen or background, and the primary object of.
the invention is to produce street or other scenes (including particularly scenes.
that change either by the movements of objects or by alterations of colors or tints)
at the back of the stages of theatres, that is to say to produce by means of
reflected light artificial scenery to take the place of the ordinary scenery or
backgrounds.
An important feature of the invention is the combination with a double lantern
or a double system of converging lenses for throwing stereoscopic or other pictures
upon a screen, of a continuous "slide" in the form of a band or strip, or double
strip, of positive photographic or other transparencies caused to travel through the
lanterns, and of a revolving cylinder or other moving device between the lenses of
each lantern, each cylinder or moving device being so formed as to cause the
intensity of the corresponding view on the screen to alternately increase gradually
to its full extent and as gradually diminish to nil, so that when one view is at its
full brightness the other view is shut off and vice versa, whilst the view on the
screen has always the same intensity of light or brightness.
When I employ revolving cylinders I construct them as follows:-Each cylinder
is formed with two diametrically opposite longitudinal openings of a width equal
to one-fourth of the circumference of the cylinder. The cylinders are placed
between the lenses of the corresponding lantern, so that the intersecting point of
the rays of light between the lenses is midway between the sides of the cylinder,
and when the cylinder revolves it follows that at a certain point of its revolution
when the middle points of the two openings are in line with the lenses the full
extent of the light passes through the cylinder and as the cylinder continues to
revolve the light is gradually shut off till at length the sides of the cylinder
completely shut off the rays.
The continuous slide or band or strip of transparencies is caused to travel inter-
mittently through the lanterns and may be unwound from a roller and wound upon
another roller, or it may be an endless band so that view after view can be exhibited
for as long a time as may be desired and the intermittent movement should be given
to the band when one of the cylinders before described completely shuts off
the light.
When it is desired to represent a street or other like scene with the continually
changing effects due to the movement of persons, vehicles or other objects the slide,
band or strip will bear a series of photographic transparencies taken from an actual
street or the like in rapid succession so as to represent the continuous changes in its
appearance.

page_text: For the purpose of producing upon the screen gradual changes of color or tint
such for exumple as will represent the changes that take place in a sunset I apply
to the transparencies ou the slides a "sympathetic" substauce, such for instance as
chloride of copper, acetate or chloride of cobalt, which upon the application of heat
gradually become colored, and which again lose their color on cooling. The
heat given out by the condenser of the lantern is sufficient to gradually bring out
the color.
In applying my invention to the production of scenes, backgrounds or drop-scenes
for theatres the lanterns should, for convenience, be placed at an elevated position
at the back of the stage and be caused to project the rays through a condensing
lens upon a prism or reflector so placed as to divert or reflect the rays through a
lens to a translucent screen or a gauze screen situated at the required part of the
stage, the position of this lens being adjustable according to the position of the screen
or the required size of the image; and in order to give any desired color or tone
to the ground of the picture I introduce a correspondingly colored film between
the lantern and the prism or reflector.
The rays of light may be caused to pass through a vignetted glass or similar
device so as to soften the somewhat hard margin of the image.
The revolving cylinders constructed and employed as above described are
applicable to ordinary apparatus used for exhibiting dissolving views; and the
application of sympathetic substances to the transparencies applicable to slides
for ordinary magic lanterns.
Dated this 29th day of November 1893.
J. C. MEWBURN,
55 and 56, Chancery Lane, London, Chartered Patent Agent.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Exhibiting Panoramic, Dissolving,
or Changing Views, and in the Manufacture of Slides for Use
therewith.
i.
I, WILLIAM FRIESE-GREENE of 39 King's Road, Chelsea, London, Photo-
grapher, 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 relates to that class of apparatus which is adapted to throw by
means of suitably arranged lenses, enlarged representations of photographic or
other transparent pictures upon a screen or background and the primary object of
the invention is to produce street or other scenes (including particularly scenes
that change either by the movements of objects or by alterations of colors or tints)
at the back of the stages of theatres, that is to say to produce by means of reflected
light artificial scenery to take the place of the ordinary scenery or backgrounds.
An important feature of the invention is the combination with a double lantern
or a double system of converging lenses for throwing pictures upon a screen, of a
continuous "slide" in the form of a band or strip, or double strip, of positive photo-
graphic or other transparencies caused to travel through the lanterns, and of a
revolving cylinder or other moving device between or in front of the lenses of each
lantern, each cylinder or moving device being so formed as to cause the intensity
of the corresponding view on the screen to alternately increase gradually to its full
extent and as gradually diminish to nil, so that when one view is at its full
brightness the other view is shut off and vice versa, whilst the view on the screen has
always the same intensity of light or brightness.
When I employ revolving cylinders I construct them as follows:-Each cylinder
is formed with two diametrically opposite longitudinal openings of a width equal to

page_text: one-fourth of the circumference of the cylinder the two openings constituting a
longitudinal slot. The cylinders are placed between or in front of the lenses of the
corresponding lantern so that the intersecting point of the rays of light is midway
between the sides of the cylinder and when the cylinder revolves it follows that at a
certain point of its revolution when the middle points of the two openings or slot
are in line with the lenses the full extent of the light passes through the cylinder
and as the cylinder continues to revolve the light is gradually shut off till at length
the sides of the cylinder completely shut off the rays.
When it is desired to represent a street or other like scene with the continually
changing effects due to the movement of persons, vehicles or other objects the slide,
band or strip will bear a series of photographic transparencies taken from an actual
street or the like in rapid succession. Each photograph of the series will represent.
a complete picture; but each photograph will differ in some slight detail from the
one preceding or following,-depending on the interval which is allowed to elapse
between the exposures. This series of photographic transparencies can be thrown
on to the screen so as to represent the continuous changes in its appearance.
The continuous slide or band or strip of transparencies is caused to travel inter-
mittently through the lanterns and may be unwound from a roller and wound upon
another roller, or it may be an endless band so that view after view can be
exhibited for as long a time as may be desired and the intermittent movement
should be given to the band when one of the cylinders before described completely
shuts off the light.
In applying my invention to the production of scenes, back-grounds or drop-
scenes for theatres the lanterns should, for convenience be placed at an elevated
position at the back of the stage and be caused to project the rays through a con-
densing lens upon a prism or reflector so placed as to divert or reflect the rays
through a lens to a translucent screen or a gauze screen situated at the required
part of the stage, the position of this lens being adjustable according to the position
of the screen or the required size of the image; and in order to give any desired
color or tone to the ground of the picture I introduce a correspondingly colored
film between the lantern and the prism or reflector.
The rays of light may be caused to pass through a vignetted glass or similar
device so as to soften the somewhat hard margin of the image.
The revolving cylinders constructed and employed as above described are
applicable to ordinary apparatus used for exhibiting dissolving views; and the
apparatus without the revolving cylinders and with the addition of shutters can be
used as a camera for producing the continuous slides.
In order that this part of my invention may be better understood I will proceed
to describe the same with reference to the accompanying drawings.
Figure 1 is a side view of my apparatus with the case removed, and adapted for
use as a camera.
Figure 2 is a section in a plane parallel to Figure 1.
Figure 3 is a view of the revolving cylinders which I employ when the apparatus
is used for exhibiting dissolving views.
Figure 4 shews diagrammatically the position of the cylinders and other parts
when in use.
Referring to Figures 1 and 2 a represents the box of the apparatus which is
furnished with two lenses bb¹.
In the back portion of this apparatus I insert a suitable frame c of brass or other
material in which are fitted the necessary rollers for winding up and winding off
the continuous film and the sectors which are to effect the drawing off of the film.
The frame e is provided with a winding off roller d one end of which fits by a
bayonet joint or otherwise into the spindle e the other end of which is furnished with
a pin which fits into a slot within which it revolves. This arrangement allows of
its being easily removed to be refilled or to be replaced by another roller.
C
The spindle is provided at one end with a loose pulley f which is mounted
thereon with slight friction. 9 and hare two guide rollers in the same frame so.

page_text: arranged as to bring the film or films in position opposite the respective lenses. ; is
another guide roller intended to guide and facilitate the movement of the film onto
the wind-up roller k. The pin or spindle on which the wind-up roller k revolves
is furnished with two wheels which are rigidly attached to such spindle; one a
toothed wheel (shown in dotted lines in Figure 1) the other a pulley which may
be connected by a strap m with the pulley to facilitate the movements.
The winding-off and winding-up rollers are furnished with a longitudinal slot in
which the film is inserted preparatory to its being wound off. nn represent the
film. oo are sectors centred on a rod p supported in the frame. The rod p is
carried in bearings in the said frame c and is provided with a spring
which serves
to assist in throwing the sector out of contact with the film. The sectors carry in
bearings an antifriction drawing rollers which is so arranged as to automatically
draw off from the winding off roller d a sufficient length of film for one exposure.
¿ is a clamp or clutch furnished with a suitable spring t to keep it in its proper
position. The film n passes between the roller and the clamp t which is so adjusted
as to allow the film to travel in one direction but prevents it from travelling in the
other direction.
26
A similar clamp u with a spring u' is in contact with the roller j and allows the
film to travel in one direction only. Similar clamps should be placed at the other
end of the respective rollers..
Motion can be imparted to the rollers and sectors in any convenient method but
I prefer that it should be given from a toothed wheel and cams fixed on the spindle
connected with the operating handle.
The operating handle A is connected with a spindle B on which is rigidly fixed
or keyed a toothed wheel C which through the intervention of another toothed
wheel D imparts the necessary motion to the rollers as explained later. The
spindle B is also provided with four cams. Two of these cams operate the
sectors o o' while the other two cams work the shutters.
E is the cam which operates the sector o; (the other cam which operates the
corresponding sector o' is not shewn in the drawings). This cam and sector are
shewn in dotted outline in their other position.
The cams F G operate the double shutter arrangement so as to give the
necessary exposure.
These shutters are removed when the apparatus is to be
used as a lantern.
'
The cams F G for operating the double shutter arrangement are constructed
to act at the proper times respectively upon levers H J which are supported in
bearings K K on the bottom of the camera. The lever H is connected to the
outer shutter L while the lever J is connected to the inner shutter M. When the
motion is imparted to the spindle B upon which are fixed the cams F G
the cam which is arranged to come first into operation, depresses its lever H
and as the motion continues this lever raises the outer shutter L. When the
outer shutter L has been lifted to a predetermined distance the cam G comes
into operation and by means of its lever J raises the inner shutter M, both
shutters at this part of the movement travelling together, although the motion of
the inner shutter is more rapid than that of the outer shutter and the motion being
so proportioned as to prevent any possibility of the apertures in the respective
shutters coinciding. This difference of speed is attained by suitably proportioning
and shaping the cams F G or otherwise as will be well understood. When the
outer shutter has been raised to a suitable height the cam F by reason of its shape
ceases to act upon the lever H; the outer shutter L therefore falls by its own
weight into such a position that the aperture therein is opposite the lens of the
camera. The cam G still continues to act upon its lever J and the inner shutter M
still continues to rise. When the inner shutter M has reached its highest position
the cam G ceases to act upon the lever J and the inner shutter M also falls to it's
lowest position. The inner shutter is arranged to fall to a lower point than the
outer shutter and it follows that in the fall of the inner shutter the aperture of the
inner shutter which is in the same perpendicular line with the aperture of the outer

page_text: butter passes and is for an instant coincident therewith; the required image is
thus received upon the film. The shutters are guided in their rise by suitable slots
working on pins or studs which serve as stops to the shutters in their lowest
position; these slots and studs are not shown in the drawings. This shutter
arrangement forms no part of my present invention and any other suitable shutter
may be substituted therefor.
The action of the apparatus is continuous and is as follows:-Motion being
imparted to the handle A the operation of the double shutter arrangement pro-
ceeds as above described. At a suitable point in the revolution of the spindle B
0 the cam E and the other cam not shown come in contact with the sectors o o' which
are thereby forced back; the drawing roller coming in contact with the film n
and forcing it back; thus the correct length of film necessary for one exposure is
drawn off the roller d. As the rotation of the spindle B continues the shutters fall
and the exposure is given. The cams then gradually recede from their respective
sectors o of which partly by the action of gravity and partly by the effect of the
returning spring a retire from the film to their normal position and the drawing
roller is thus thrown out of contact with the film. The slack thus periodically
produced in the film is automatically wound upon the winding up roller k by means
of the toothed wheels herein before described.
drawn out by the action of the sectors and the same series of operations is gone
A fresh length of film is then
through.
Figure 3 shews one form in which my two cylinders can be used; they are
preferably placed in front of the lenses >> ¹.
J
:
The cylinders N are formed with a slot or hole Peach slot or hole being about.
one quarter of the circumference. The cylinders are mounted in a suitable frame Q
the axis of each cylinder being preferably prolonged so that they can be connected
by any suitable driving gear.
In the illustration the axis is provided with a worm wheel R to which motion is
imparted by a worm driven by hand. The cylinders can be driven by a small
electric motor or in any other convenient method. These two cylinders should be so
adjusted that the plane of the slot of one cylinder is at right angles to the plane of
the slot of the other cylinders, and the gearing for working these should be driven
from the same prime mover as the gearing for working the winding-off and
winding-up rollers and sectors.
Figure 4 is a diagrammatic view showing the adaptation of a double system of
converging lenses with a translucent screen and stage.
The light S passing through condensers T and through the films or continuous
slides (not shown) to the lenses V converge through the cylinders N which are
those shown in Figure 3 upon a prism W whence they are diverted at right angles
through a lens X to impinge upon a translucent screen Y interposed between the
stage front footlights and the back of the stage.
The main object of the prism and lens is to make the invention adaptable
where space is limited.
When space allows the image to be thrown direct on to the screen the prism and
lens can be dispensed with.
It will be readily seen that the same apparatus which serves as part of the
lantern also serves with the addition of shutters as the camera for the purpose of
taking a continuous series of photographs for subsequent use in the lantern.
In using the apparatus as a camera the back is closed for the purpose of taking
the photograph and the only change necessary in order to convert the camera into
the lantern apparatus for throwing the image on the screen is to remove the shutters
and the back (as seen in the drawings) and place the condenser behind the
apparatus and the cylinders N in position.
mage is produced on the film, so is the image thrown on the screen.
In the same way as the original
:
It is important that the conditions of taking the image should be exactly adhered
o when throwing the image on the screen.
The continuous film previously mentioned contains a series of photographic

page_text: TO
images each of which is a perfect photograph in itself and perfectly sharp.
taking these photographs it is usual for the film to be stationary whilst the photo-
grapli is being taken.
In carrying out my invention the film may when taking the series of images be
continuously drawn through and a revolving shutter be used so as to give
intermittent exposures.
The film on being developed will not shew a series of
distinct photographs but it will show a bleared mass. By using the same instrument
as a lantern it will be found that by throwing this film (containing a bleared mass)
on to the screen the objects will come out as they appear to the eye in actual life.
In adopting this course I prefer to insert a piece of pale green glass in the lens, as
I find that the image is more defined when subsequently thrown on the screen.
For the purpose of producing upon the screen gradual changes of color or tint
such for example as will represent the changes that take place in a sunset I apply
to the transparencies on the slides a "sympathetic" substance, such for instance
as chloride of copper, acetate or chloride of cobalt, which upon the application of
heat gradually become colored, and which again lose their color on cooling. The
heat given out by the condenser of the lantern is sufficient to gradually bring out
the color.
I have found that certain coal tar colors are sympathetic to heat in the manner
above stated; in particular several coloring matters of the phenol series but I do
not recommend their use as I have found that they require more heat than those
above specified, and that a sufficient range of color can be obtained from those above
specified.
In order to obtain violet I prefer to use acetate of cobalt and in order to obtain
blue I prefer to use chloride of cobalt; whilst yellows may be obtained by using
chloride of copper. By an addition of a small quantity of iron to the chloride of
cobalt I obtain green. By mixing these colors or by diluting them it is possible to
obtain a variety of colors and if necessary any coloring matter may be added. The
application of sympathetic substances to the transparencies is applicable to slides.
for ordinary magic lanterns.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what [
claim is :-
1. For exhibiting panoramic, dissolving or changing views, the combination
with a double lantern or a double system of converging lenses, of means for causing
a continuous "slide" to travel through the lanterns or double system of lenses and
of revolving cylinders or other moving devices in front of or between the lenses of
each lantern or each set of lenses each such cylinder or moving device being so
formed as to cause the intensity of the corresponding view on the screen to
alternately increase gradually to its full extent and as gradually diminish to nil so
that when one view is at its full brightness the other view is shut off and vice versa
whilst the view on the screen has always the same intensity of light or bright-
ness, substantially as herein before described.
2. The particular construction and arrangement of two revolving cylinders
substantially as hereinbefore described for use in the manner and for the purpose
set forth in apparatus for exhibiting dissolving views.
3. The particular combination and arrangement of rollers and sectors for the
purpose of causing a continuous film to travel, substantially as and for the
purposes hereinbefore described.
4. The use, in combination, of a double lantern or a double system of converging
lenses, a continuous slide caused to travel through, the lanterns or double set of
lenses, revolving cylinders or other moving devices such as described coacting so
as to maintain a uniform intensity of light on the screen, a condensing lens, a
prism or reflector, a lens and a translucent or gauze screen, whereby the images
upon the slide can be reproduced upon the screen substantially as and for the
purpose herein before described.

page_text: 5. The application to continuous or other lantern slides or transparencies of
substances which are sympathetic to heat for the purpose of producing colored
and changing effects, substantially as hereinbefore described.
Dated this 1st day of October 1894.
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London, Patent Agents.