IMPROVE- MENTS IN APPARATUS TO BE USED IN THE EXHIBITION OF DRAMATIC, DIORAMIC, AND OTHER LIKE PERFORMANCES
Year: 1879

page_text: LETTERS PATENT to John Henry Pepper, of No. 16, Calverley Park Crescent,
Tunbridge Wells, in the County of Kent, and James John Walker, of No. 27,
Francis Street, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN APPARATUS TO BE USED IN THE EXHIBITION OF DRAMATIC, DIORAMIC,
AND OTHER LIKE PERFORMANCES."
Sealed the 1st July 1879, and dated the 28th March 1879.
PROVISIONAL SPECIFICATION left by the said John Henry Pepper and
James John Walker at the Office of the Commissioners of Patents on the 28th
March 1879.
JOHN HENRY PEPPER, of No. 16, Calverley Park Crescent, Tunbridge Wells, in the
County of Kent, and JAMES JOHN WALKER, of No. 27, Francis Street, in the County
of Middlesex. "IMPROVEMENTS IN APPARATUS TO BE USED IN THE EXHIBITION OF
DRAMATIC, DIORAMIC, AND OTHER LIKE PERFORMANCES."
The object of our Invention is by a peculiar arrangement of apparatus to render
an actor or object gradually visible or invisible at will, and also to substitute for an
object in sight of the audience the image of another similar object hidden from direct
vision without the audience being aware that any such substitution has been made.
For this purpose we employ a large plate of plate glass which is transparent at
one end and more and more densely silvered in passing from this towards the other
end. We mount this plate so that it can at pleasure be placed diagonally across
the stage or platform. As it advances the glass gradually obscures the view of the
actor or object in front of which it passes, and substitutes the reflection of an
object in front of the glass, but suitably concealed from the direct view of the
audience.
When the two objects (or sets of objects) thus successively presented to the view

page_text: are properly placed and sufficiently alike the audience will be unaware that any
change has been made.
In some cases in place of a single sheet of glass we employ two or more sheets.
We also employ a graduated diagonal mirror in exhibiting dioramic views upon
a screen. By inserting the diagonal mirror between the slide and the lens of the
lanthorn the image of another slide may be gradually substituted upon the screen
for that first exhibited.
For some effects, as for the introduction at pleasure of a faint image in the midst
of a picture remaining continually on the screen, we use in a similar manner a
diagonal mirror of unsilvered glass.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Pepper and James John Walker in the Great Seal Patent
Office on the 27th September 1879.
JOHN HENRY PEPPER, of No. 16, Calverley Park Crescent, Tunbridge Wells, in
the County of Kent, and JAMES JOHN WALKER, of No. 27, Francis Street, in the
County of Middlesex. "IMPROVEMENTS IN APPARATUS TO BE USED IN THE EXHI-
BITION OF DRAMATIC, DIORAMIC, AND OTHER LIKE PERFORMANCES.”
"
The object of our Invention is, first, by a peculiar arrangement of apparatus to
render an actor or object gradually visible or invisible at will, and also to substitute
for an object in sight of the audience the image of another similar object hidden
from direct vision without the audience being aware that any such substitution has
been made.
For this purpose we employ a large mirror, either an ordinary mirror, or for some
purposes by preference a large plate of plate glass which is transparent at one end,
and more and more densely silvered in passing from this towards the other end.
We mount this mirror or plate so that it can at pleasure be placed diagonally across
the stage or platform. As it advances the glass obscures the view of the actor or
object in front of which it passes, and substitutes the reflection of an object in
front of the glass, but suitably concealed from the direct view of the audience.
When the two objects (or sets of objects) thus successively presented to the view
are properly placed and sufficiently alike the audience will be unaware that any
change has been made.
In some cases in place of a single sheet of glass we employ two or more sheets.
We also employ a graduated diagonal mirror in exhibiting dioramic views upon
a screen. By inserting the diagonal mirror between the slide and the lens of the
lanthorn the image of another slide may be gradually substituted upon the screen
for that first exhibited.
For some effects, as for the introduction at pleasure of a faint image in the midst
of a picture remaining continuously on the screen, we use in a similar manner a
diagonal mirror of unsilvered glass.
In order that our said Invention may be most fully understood and readily
carried into effect we will proceed to describe the Drawing hereunto annexed.
DESCRIPTION OF THE DRAWING.
Figure 1 of the Drawing represents a plan view of an arrangement such as
herein before first described.
a is a stage; it may be in a lecture room or theatre; b, b, are the seats for the
audience in front of the stage; c is a small room, ten or twelve feet square and
eight feet high will often be sufficiently large, but it may be of any size; it may
advantageously be raised and approached by two or three steps from the stage; d is
a vertical mirror passing diagonally across the chamber c and dividing it into two
parts, which are exact counterparts the one of the other. The mirror d is so
mounted that it can be rapidly and noiselessly withdrawn whenever desired; this
can conveniently be done by running it in guides and upon rollers to a position d¹
where it is hidden by a screen which limits the view of the audience in this
direction, or the mirror might be raised and lowered vertically.
it
It is not necessary that the mirror should pass entirely across the chamber c,
might, especially when the chamber is of large size, pass only partly across it.
In consequence of the exact correspondence of the two parts of the chamber c,
that in front and that behind the mirror, the audience will observe no change in
appearance when the mirror is passed across.
The front of the chamber is in some cases partly closed at c*, either permanently
or whenever required; this is done in order to hide from direct view any object
which may be at or about the position c³,
:

page_text: The illusions may be performed in various ways; but, for example, an object
may, in sight of the audience, be passed from the stage to the position c² and there
be changed for some other. This is done by providing beforehand a dummy at c¹
closely resembling the object at c². Then when the object is in its place the mirror
is passed across without causing any apparent change. The object, when hidden, is
changed for another object externally resembling the first, the mirror is withdrawn,
and the audience may then be shown in any convenient way that the object now
before them differs from that which they at first had seen.
We prefer in many cases not to use an ordinary mirror at d but one of graduated
opacity. This may be produced by removing the silvering from the glass in lines,
or if the glass be silvered by chemical deposition causing the silver to he deposited
upon it in lines. Near one side of the glass the lines are made fine and open and
progressively, in passing towards the other side they become bolder and closer until
a completely silvered surface is reached. Or other ineans for obtaining a graduated
opacity and reflecting power may be resorted to.
By passing such a graduated mirror between the object at c³ and the audience
the object may be made to fade from the sight or gradually to resolve itself into
another form.
In order that the edge of the glass mirror may not be observed as the mirror is
moved across the chamber c we in some cases form the forward edge of the mirror
in steps, say, of about 1/8th of an inch in depth, as shown at Figure 2, in place of
simply forming it with a square end. The edge will thus, as it were, be broken up
into a number of comparatively narrow edges, each one of which is practically
invisible at the distance at which the spectators are separated from it. The objects
at c¹, c, may be illuminated by a lamp or lamps at e, or by lamps at f, f; or over-
head lights might be used, or especially if the forward edge of the mirror is formed
in steps, as above described, a strong front light may be used for illuminating the
objects.
.
Figure 3 is a diagram view shewing how a graduated diagonal mirror may be
used with a lanthorn, such as is used for exhibiting dioramic views upon a screen.
A is the lens; B, the mirror which can be drawn backwards or forwards at pleasure
in a diagonal line across the box or case E.
The slides can be placed in position either at C or D; separate lamps outside of
the box or case E are used for illuminating the slides in the two positions.
When the mirror is drawn back the slide C will be thrown by the lens on to the
screen, but when the mirror is moved forwards across the lanthorn the slide D
being then reflected to the lens by the graduated mirror will gradually be substi-
tuted for the slide C.
What we claim is,―
First. The combination of the symmetrical chamber c and moveable diagonal
mirror d, substantially as described.
Second. We also claim the combination of a symmetrical chamber c with a
moveable diagonal mirror a having a graduated opacity and reflecting power,
substantially as described.
Third. Forming apparatus used for exhibiting dioramic views with a moveable
graduated diagonal mirror or a diagonal mirror of unsilvered glass, substantially as
herein before described.
In witness whereof, I, the said James John Walker, have hereunto set my
hand and seal, this Twenty sixth day of September, in the year of our
Lord One thousand eight hundred and seventy nine.
JAMES J. WALKER. (LS.)