Improvements in Magic Lanterns and Dissolving View Apparatus.
Year: 1896

page_text: Date of Application, 29th Oct., 1896-Accepted, 5th Dec., 1896
COMPLETE SPECIFICATION.
Improvements in Magic Lanterns and Dissolving View
Apparatus.
1, HORACE LORENZO HASTINGS, residing in the City of Chelsea, County of Suffolk,
in the State of Massachusetts, United States of America, Editor, Publisher, and
Lecturer, 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 :-
In the use of magic lanterns as hitherto constructed, there occur certain disagreeable
incidents. In exhibiting pictures with a single lantern, as the views are changed
dark shadows pass across the screen, and every motion of the picture is visible. If an
opaque shutter be used to conceal these objectionable appearances, the alternations of
bright light and intense darkness, are wearisome and trying to the eyes of spectators,
and thus detract from their instruction, amusement and comfort. When, to avoid
these evils, two lanterns are used alternately to produce dissolving views, there is
then an unpleasant fizzing noise caused by the gas in reheating the calcium; and
there is also danger of extinguishing the light, or breaking the calcium, thus leaving
the assembly in darkness until the calcium can be replaced and the
gas re-lighted.
Besides there is the extra cost of a second lantern, the burden of its transportation,
and the expense of an expert assistant who is required to work the lantern.
It is to obviate these disadvantages, and to provide means to so adjust the picture
slides in the lantern that they may stand parallel to a perpendicular screen, thus
securing a focus instantaneously, that my device has been invented; and in order that
my invention may be easily understood and constructed with facility, I accompany
this specification with drawings which constitute a part of it in which
Figure 1 is a plan of my device.
Figure 2 is a front elevation of the shutter carrier.
Figure 3 is a front elevation of the picture slide carrier.
Figure 4 is a front and end elevation of the picture carrier guide; and the letters
and designatory signs in either figure are the same for the same parts in all the
figures-and with the following descriptive statement:
My invention consists of a method and devices to adjust the picture slide itself in
the lantern parallel to the screen on which the picture, when projected from the
lantern, is to be exhibited to the audience, and also to use in front of the objective
lens translucent shutters of sufficient opacity to gradually obscure or break up the
definition or form of the picture on the screen-producing by this device an effect
with one lantern quite similar to the dissolving heretofore produced by two lanterns,
as before described-while at the same time that the picture disappears, a field of
sufficient light remains on the screen, to entirely avoid the tiresome and hurtful
alternations of light and darkness before described :-These translucent shutters
being so connected automatically with the picture carrier properly fitted for the
purpose, that when the picture is obscured by the closing of the shutters across the
cone of light, the operator can by means of this invention, while this obscuration
continues, remove the picture which has been shown, and bring the picture next
to be shown into position to be seen when the shutters are withdrawn and the
obscuration removed. This may be understood by referring to the drawings connected
with this specification as follows:
A. Fig. 1 is a guide" or support-sometimes called a "stage"--which will be.

page_text: "
minutely described at a future point in this statement; in which the picture carrier B
is caused by my invention to move across the cone of light from the lantern. The
"guide" A is so made and attached to the lantern that it in no way interferes with
the light from the lantern shining through the lenses constituting the "condenser" D,
and the "objective" D'. The picture carrier B has two square apertures CC, the
distance of whose centers from each other is equal to the necessary distance between
the centers of two pictures. The picture carrier B has also two recesses for
holding pictures, represented by the parallelogram dotted lines E, concentric with
the squares CC. The circles D and I represent the position of the "condenser"
and objective" of the lantern. It is obvious that this picture carrier B will hold
two pictures, so that by sliding it end wise they can be alternately placed in the cone
of light passing through the lenses of the lantern, and projected on the screen.
Now F shows a guide or shear attached to the picture carrier B, and G shows a
crank-shaped arm attached to the end of the shaft H; the center of this shaft is at
such a distance from the guide or shear F that when it is rotated the crank pin will
pass between the parallel sides of the shear, and remain in contact with it while the
shaft makes one-half rotation, and will thus cause the carrier to take such motion
end wise as is needed to move either picture from the field of exhibition and move
the other into that position-the direction of the motion of rotation will determine
the proper sequence of picture changes. I, is a "shutter-carrier" attached to the
outer end of the "objective" cell. The continuous and dotted lines J and K are two
semi-opaque or translucent shutters, which are held in the carrier I, and are cansed to
pass across the field of the objective D, and this operation may be performed by the
hand by grasping the pin L, which is inserted in the shutter J, and pushing the
shutter across the face of the "objective," or it may he done by the action of
cam M, which is borne on the shaft H. This cam, when the shaft is rotated, comes
in contact with the pin L, and by forcing it farther from the shaft pushes the
shutter J across the opening of the field of the "objective" to cover full one-half its
aperture, while the shutter K is attached to the shutter J by the flexible connection X,
which passes around roller Y, and gives shutter K motion in a direction opposite to
shutter J. Thus shutter K is by the same pressure of the hand or cam made to move
across the aperture of the "objective" to a like distance with the other shutter, thus
completely covering the field of the lenses. NN represent elastic springs, which
being attached to pins OO in the shutter-carrier I, and to pins P P, one in each
shutter, cause the shutters to open when the pressure that shuts them is removed.
Qis a handle, or other efficient means, by which the shaft H can be rotated. R is a
bearing of the shaft H, attached to the shutter-carrier. S S are bearings of the
shaft H in the top of a stand, by which our device is attached to the base on which
the lantern is fixed. As in halls of different sizes the distance between the condenser-
lens and the objective has to be varied to give the right focus of the lantern to
produce a clear picture on the screen, the shaft H is splined and made capable of
being telescoped or adjusted longitudinally on itself, so as to allow obtaining the
needed distances of those parts.
In Fig 2, I is the shutter-carrier, D' is the aperture of the "objective," JK are
the semi-opaque shutters, N N are the elastic springs, O O are the pins in the shutter-
carrier, and P P are the pins in the shutters to which these springs attach. L is the
pin in the shutter J by which the shutters are moved. X is the flexible connection
uniting the shutters. Y is the roller around which this connection passes.
In Fig. 3, B is the picture carrier, the dotted and continuous line circle D is the
"condenser," C C are the square apertures. The dotted lines E are the recesses for
holding the pictures. F is the guide or shear. G is the crank-shaped arm. His
the shaft. is the T-shaped base of the picture carrier by which it is connected
with the guide.
In Fig. 4 is a front and end elevation of the adjustable "picture-carrier guide"-
or stage which in the end view is represented as attached to a broken-off portion of
the lantern 1. A is the "guide," T are ears to connect it to the lantern at the sides.
The ears have slots U, through which thumb screws V connect with brackets W on

page_text: the bottom of the "guide." Z (dotted lines in the front elevation) is a T-shaped
recess of the "guide" in which the picture-carrier is so held that it may slide
endwise in the operation of changing the pictures.
It often happens that the lantern cannot be set exactly in front of the center of
the screen on which the picture is shown, but in some audience rooms must be
set above, below, or on one side. In this case the picture slide in the lantern is not
parallel to the screen, and for that reason one portion of the picture on the
screen will be dim, while the others, are distinct, this effect resulting from the fact
that a portion of the screen from its want of parallelism with the picture is not
at the proper focal distance from the picture slide in the carrier; a difficulty which
has hitherto necessitated the laborious and undesirable readjustment of the screen
at such an angle that the screen will be exactly parallel to the front of the
"objective," after which adjustment the screen hangs obliquely to the line vision
of the audience, which position is undesirable. To avoid this difficulty, this
improvement includes thoroughly efficient, simple, and easily operated means in
the arrangement and construction of the picture-carrier guide A, by which the
picture can be adjusted exactly parallel to the screen-see Fig. 4 which gives a
front and end elevation of the picture-carrier guide A. The carrier-guide is so
made that it is attached to the lantern by ears T, having slots U in them in the
horizontal line, through which the screws V are inserted, which connect the ears
to the brackets W which sustain the carrier-guide or stage. When the lantern needs
to be located at one side of the audience room, instead of being placed exactly in
front of the screen, by loosening the screws V, and readjusting them in their slots,
the carrier-guide can be swung around on its vertical axis to the position necessary
to render the picture slide exactly parallel to a screen hung squarely before an
audience. And when the lantern must be placed either higher or lower than the
center of the screen, the carrier-guide can be swung on a horizontal axis, supplied
hy the same screws V, by simply tipping the slide-carrier backward or forward as far
as is necessary to bring the picture slide into a position parallel to the perpendicular
screen. By this means the picture slide can be instantly adjusted so that all parts of
the picture will be in accurate focus on the screen.
Now it will be manifest that, all the parts of this device being properly adjusted, if
the shaft H be caused to accomplish about one-half of a complete rotation, the cam M
will move the semi-opaque shutters J and K across the field of the lantern, and
obscure the picture on the screen, causing it gradually to fade out, while the screen
will still show a field of white light; and at the same time that the picture has
become obscured, the crank arm G will connect with the guide or shear and cause
the carrier B to slide in the guide A, and will thus carry the picture to be removed
out of the field of the lantern and place the new picture in the field, when, the
rotation being continued, the crank arm will disconnect itself from the shear-its
connection being intermittent-and leave the picture standing still; the cam M will
then retreat and leave the shutters J and K free to be opened by the springs, and the
new picture will then gradually appear on the screen. The "dissolving" and
changing of the picture is thus accomplished automatically by a single turn of the
shaft H. The pictures are thus so changed that their motion is unseen, and the before
described faults and imperfections of operation are avoided. As the shaft does not
form rigid attachments to the shutters J and K and the carrier B, these may be also
operated independently by hand when it is desirable to produce various effects, the
semi-opaque shutters being still used and necessary in front of the "objective," to
produce the disappearance or dissolving of the picture.
It is obvious that many forms of device to attach an adjustable guide or stage to a
lantern could be used, and many forms of guide-way for the picture-carrier, and of
means to give the carrier motion end wise could be devised, but as they all must
involve practically the same principles as those which, as being both simple and
efficient, I describe, I need not extendedly describe them to defend myself against
their being used as means of evading my claims.

page_text: 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 I
claim as my invention is
1. In a magic lantern, or other optical instrument of that class, an adjustable
picture-carrier guide, or stage, with means of attaching the guide to the lantern, and
of adjusting the plane of the guide parallel to the screen, for the purpose as shown
and described.
2. In a device of the character described, the combination of a picture-carrier
guide, or stage, adjustable to the plane of the screen on which the picture is shown;
a picture-carrier having a shear attached; a crank-shaped arm forming an
intermittent connection with the picture-carrier; a shaft bearing the crank-shaped
arm, and having an adjustment lengthwise; a cam on the shaft which forms
connection with the semi-opaque material in the shutter-carrier fixed to the front of
the "objective"; and suitable means of imparting a rotating movement to the shaft,
adapted to give automatically a reciprocating motion to the picture-carrier and
shutters, for the purpose shown and described.
Deted this Tighth done of Antahan 100%
Witnesses:-
-
JOHN KING HASTINGS.
PETER OLSON.
HORACE LORENZO HASTINGS.