Magic, Stage Illusions and Scientific Diversions, Including Trick Photography
CHAPTER III.
855 words | Chapter 109
THE PROJECTION OF MOVING PICTURES.
THE EDISON KINETOGRAPH.
[Illustration: PHOTO-ENGRAVING OF A PORTION OF THE STRIP NEGATIVE OF THE
KINETOGRAPH (ACTUAL SIZE).]
The “kinetograph,” which is the precursor of the apparatus for showing
moving photographs, is of great interest. The kinetograph as first
proposed consisted of a clever combination of a photographic camera and
the phonograph, by which the words of a speech or play were to be
recorded simultaneously with photographic impressions of all the
movements of the speakers or actors. The photographic impression is
taken at the rate of forty-six per second. The celluloid film upon which
the photographic impressions are taken is perforated along one edge with
a series of holes, arranged at regular intervals with as much precision
as can be secured by means of the finest perforating mechanism, to
secure perfect registry. This was found necessary because the
phonographic cylinder must be in exact synchronism with the
shutter-operating and film-moving devices of the camera. The phonograph
and camera mechanisms are driven by the same motor and controlled by the
same regulating mechanism. The greatest difficulty was experienced in
devising mechanism for the stopping and starting of the film. It was
found that the stopping and starting of the film forty-six times a
second required about two-thirds of the time, the remainder being
utilized for the exposure of the plate. To take these pictures special
camera lenses of large aperture had to be constructed. The reproducing
apparatus is practically a reversal of the camera; that is, a superior
form of projecting lantern is employed which is provided with a strong
light, and mechanism for moving forward the strip with an intermittent
motion, corresponding exactly to the motion of the negative strip in the
camera. The lantern is furnished with a light interrupter which eclipses
the light during the brief period required for shifting the film
forward to a new position to show the succeeding picture. The apparatus
was largely manufactured on a small scale, without the phonograph, for
use in railway stations, cigar stores, etc. It was found to be almost
impossible to combine the two instruments. In this case the pictures
were not projected upon the screen, but were upon a ground-glass plate
which the observer looks at.
REYNAUD’S OPTICAL THEATER.
Up to the time of the invention of this theater, the apparatus that
produced the synthesis of the successive phases of an action were
limited to reproduction upon a very small scale, which can only be
enjoyed by a limited group. The object of the optical theater was to
provide an apparatus for the reproduction of a series of actions upon a
considerable scale. The continuity of the image obtained by the
praxinoscope, invented in 1877 by M. Reynaud, had not up to this time
been realized by any projecting apparatus. The effect is produced by
using a crystalloid band upon which the images are painted as
represented at A in our engraving. The operator can revolve it in one
direction or the other by means of two reels. The images pass before the
lantern, B, and are projected by the aid of the objective, C, upon an
inclined mirror, M, which projects them upon the transparent screen, E.
Another projection lantern, B, causes the appearance on the screen of
the scene, amid which appear the characters, which change their posture
according as the painted band, A, is revolved by the operator.
[Illustration: REYNAUD’S OPTICAL THEATER.]
ELECTRIC TACHYSCOPE.
The apparatus which we are about to describe is an important link in the
history of the synthesis of animated motion. The apparatus is the
invention of Ottamar Anschuetz, of Lissa, Prussia. A special camera was
used, adapted to take a number of photographs in quick succession. The
instrument for displaying the pictures is called the “electrical
tachyscope.” It consists of an iron wheel of sufficient diameter to hold
an entire series of positive prints on the periphery. The wheel is
arranged upon a rigid standard, and provided with a series of pins which
register exactly with the picture. Upon the standard behind the wheel is
located a box containing a spiral Geissler tube which is connected with
the terminals of a Ruhmkorff coil. The primary coil is provided with a
contact maker and breaker adapted to be operated by the pins projecting
from the wheel, so that every time a picture comes before the Geissler
tube it is illuminated by an electrical discharge through the tube.
This discharge, being instantaneous, shows each picture in an apparently
fixed position. These pictures succeed each other so rapidly that the
retinal image of one picture is retained until the next is superimposed
upon it, thereby giving to the observer the sense of a continuous image
in constant motion.
[Illustration: ANSCHUETZ’S ELECTRICAL TACHYSCOPE.]
THE DEMENY CHRONOPHOTOGRAPHIC APPARATUS.
The chronophotographic apparatus which we illustrate was invented by M.
G. Demeny, who is the assistant of Dr. Marey, whose work in
chronophotography we have already described. As long ago as 1891, M.
Demeny was able to project upon a screen figures which simulated the
motion of animal life.
[Illustration: FIGS. 1 AND 2.--THE DEMENY PROJECTION APPARATUS.
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