Improvements in or relating to Phenakistoscopes, Zoetropic Slides for Magic Lanterns, and like Apparatus.
Year: 1893

page_text: Date of Application, 30th June, 1893
Complete Specification Left, 30th Mar., 1894-Accepted, 30th June, 1894
PROVISIONAL SPECIFICATION.
Improvements in or relating to Phenakistoscopes, Zoetropic Slides
for Magic Lanterns, and like Apparatus.
I, GEORGES DEMENY, of 95 Boulevard Beaumarchais, Paris, in the Republic
of France, do hereby declare the nature of this invention to be as follows:-
Instruments which depend for their operation upon the persistence of visual
impressions, have, as is well known, been made to reproduce the motions of the
features during speech, either directly, or by projection by means of a light.
These instruments are based on the successive observation of several photo-
graphic images of a person speaking, taken at very short intervals of time; the
observations being made as nearly as practicable in the same time as serves for the
photographic exposure.
Whether the said instruments be employed for direct view or for projection, the
positive images are generally arranged on the circumference of a disc to which is
imparted a movement of rotation, so that the images are successively seen by the
observer or are successively projected onto a screen, at each passage, in front of
the objective, of a window formed in an illuminated disc revolving at a high
speed.
The positive images must, therefore, be very accurately spaced on the image-
carrying disc in order that they may occupy the desired positions with respect to
each other, so that, when the image-carrying disc is rotated, they will be exactly
superposed and will present the illusion of an animate figure to the eye of the
observer.
The lengthy and careful adjustment of the apertures renders the cost of these
instruments very high and forms a serious obstacle to the industrial development
which they are capable of receiving.
It is with the object of overcoming this obstacle, by diminishing the cost of
manufacturing the discs carrying the positive images, that I have designed the
following method of manufacture:-
The various pictures of the moving figure are preferably taken on a sensitized film
in the form of a band which is unrolled in the photochronographic apparatus.
I develop the negatives thus obtained, by the operations daily performed in the
photographic art. I thus obtain a series of negatives which I cut preferably so as
to separate the said negatives from each other, and afterwards fix them separately
in any convenient manner near the circumference of a supporting disc, preferably
an opaque disc provided with openings or windows, formed near the circumference
thereof, at the same time taking care that they are arranged in the same order as
that in which they were taken during the exposure. This operation naturally
necessitates a very long and careful adjustment, but when this adjustment is
once effected, a negative is produced from which any desired number of positives
may be printed, without having to repeat the above described adjustment for each
of these positives.
If the period of motion which it is desired to reproduce necessitates the employ-
ment of a greater number of pictures than can be conveniently arranged around a
disc or plate, I replace this disc by a drum on which is helically arranged a band
carrying the different pictures obtained during the sitting; a combined motion of
rotation and translation along its axis is imparted to this drum, the latter motion
being so calculated that the drum is displaced longitudinally through a distance
equal to the width of the band during each revolution, so that the observer
apparently looks through a fixed slit; when the drum is in motion, the observer

page_text: successively sees the whole of the pictures, which consequently present the illusion
of an animate figure. The arrangement of the images on the band necessitates a
very lengthy adjustment, which I obviate as above described, by performing it with
the negatives once for all, from which I can print as many copies as may be desired,
any suitable manner.
in
It is obvious that my improved method of preparing the moving images may be
applied to phenakistoscopes and other instruments of the kind or class above
referred to.
Dated the 26th day of Juna 1802
D. YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C.,
Agents for the Applicant.
DI DUIFICATION.
Improvements in or relating to Phenakistoscopes, Zoetropic Slides
for Magic Lanterns, and like Apparatus.
I GEORGES DEMENY of Levallois-Perret, near Paris, France, but late of
95 Boulevard, Beaumarchais, Paris, 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 :—
The apparatuses called phenakistoscopes reproduce as is known, the illusion
of the movements of speech and of the physionomy either by direct vision or by
projection by means of a lime or other light.
These apparatus are based on the successive observation of the various photo-
graphic images of a person speaking taken at very short intervals of time, the
observation being made as near as possible in the same total time as that in which
the photographic proofs have been taken.
Whether the phenakistoscopes are used for direct or reflected observation the
positive images are generally arranged about the circumference of a disc which is
rotated at a speed calculated in such manner that the successive images are seen
by the observer or projected upon a screen at each passage in front of the lens, of
an opening made in an illuminating disc turning at a high speed.
The positive images must therefore be very exactly adjusted on the disc carrying
the images in order that they may occupy, one in respect of another, the desired
positions so that on the rotation of the image disc they may register exactly with
the eye of the observer and give the illusion of an animated figure.
This long and minute adjustment increases in a large proportion the price of the
apparatus and forms a serious obstacle to the industrial development which the
apparatus are susceptible of receiving.
It is with the view to surmount this obstacle by reducing the cost price of
these positive image discs that I have devised the following manner of preparing
them.
The different photographs of the animated figure are taken on a band of
sensitized paper which unwinds in chronophotographic apparatus. I develop the
negatives thus obtained by subjecting them to the manipulations practised daily in
photography. I thus obtain a series of negatives which I cut in such manner as to
separate them one from the other then I fix them singly by any suitable means on
the circumference of a disc acting as a support mostly on an opaque disc provided
with openings against each of the openings a made towards the exterior of the
opaque disc A, Fig. 1, taking care to arrange them in the order in which they have
been obtained during the exposures. This operation evidently necessitates a very
long and very minute adjustment, but once completed, I have a negative from
which to obtain as many positive proofs as I wish without having to make again
for each of these positives the adjustment which it has been previously necessary

page_text: to make. I can also arrange two concentric circles of images on a disc provided
with two concentric series of windows (Fig. 2) passing before the eyes in such
manner that the images fixed against the openings a and a', which are taken in
stereoscopic series, are seen at the same time. "I call this arrangement the zoetropic
stereoscope.
If the period of movement which it is desired to reproduce necessitates too large
a number of photographs to be arranged on a disc or plate, I replace this by a
drum B on which is wound in a helical form a band b on which are placed side by
side the images obtained during the exposures, the drum is subjected at the same
time to a rotating movement and to a displacing movement along its axis, this last
movement being calculated in such manner that the drum is displaced by a distance
equal to the width of the band b so that if the observer looks through a fixed slot
the drum being in movement he will see all the images successively giving the
illusion of an animated figure. The placing of the images on the band necessitates
a long adjustment which I suppress as before by effecting it once for all in the case
of the negatives from which I can take a number of proofs as large as 1 desire, and
which can be reproduced by any suitable manner.
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 is :-
The methods above described with the view to obtain very simply positive image
discs or bands for phenakistoscopes which have hitherto required a very long and
minute adjustment, these methods being particularly characterised.
1. In the case of discs by the arrangement of negative images against openings
made towards the exterior circumference of an opaque or other disc acting
as a support, the said negatives being carefully adjusted with the view to
constitute a single zoetropic negative from which may be taken by the
ordinary methods of photography as large a number of positives as may be
desired.
2. In the case of discs by the arrangement of the negative images adjusted
with care around the circumference of a disc and placed on two concentric
circumferences in such manner that taken two by two the images are
stereoscopic images and passing in front of the eyes at the same time they
produce the illusion of movement and relief.
3. In the case of bands wound helically on a drum the application of the same
process consisting in adjusting on an opaque sheet provided with openings
or even on a transparent substance, the negative images obtained in such
manner as to constitute a complete negative giving at once and without
further adjustment positive image bands which placed in the apparatus
called phenakistoscopes give the illusion of life like movements.
Dated this 30th day of March 1894.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.