At the time that we described the Demeny chronophotographic apparatus
we remarked that it had the advantage of permitting of the projection
of very luminous images of large dimensions; but it is certain that
the cases are somewhat limited in which there is any need of using a
screen 24 or 25 feet square, and, as a general thing, one 6 or 10 feet
square suffices. The manufacturer of the apparatus, M. Gaumont, has,
therefore, been led to construct a small size in which the bands have
the dimensions usually employed in the French and other apparatus,
thus permitting of the use of such as are now found in abundance in
the market.
By reducing the size, it has been possible further to simplify the
construction, and at the same time to reduce the price, thus making of
the new form a genuine amateur apparatus.
It will be remembered that the Demeny principle consists especially in
the avoiding of traction upon the perforated part of the band, which
is the portion that always presents the most fragility. This principle
has naturally been preserved in the small model, and a preservation of
the bands for a long time is thus assured.
[Illustration: FIG. 1--ARRANGEMENT OF THE SENSITIZED BAND IN TWO
MAGAZINES.]
[Illustration: FIG. 2--ARRANGEMENT FOR TAKING VIEWS WITH SPECIAL
GEARING FOR THE WINDING OF THE BAND.]
The apparatus is reversible, and may be used for making negatives as
well as for projecting positives. In its new form it is easily
transportable and is no more bulky than an ordinary 5 by 7 inch
apparatus. Nothing is simpler then than to carry it on a journey, if
one desires to make his own negative bands. Since the sensitized film
has to be protected against the light during its entire travel, two
magazines have been arranged (Fig. 1). One of these, A, which is fixed
upon the top of the camera, contains the clean film, while the other,
B, which is placed beneath the objective, receives the strip after it
has been acted upon by the light. A train of toothed wheels, C (Fig.
2), actuates the roller of this second magazine. This arrangement may,
moreover, be utilized also when projections are made, if one does not
desire the band to float in measure as it unwinds behind the
objective. As the upper magazine is entirely closed when it is placed
upon the apparatus, it is necessary, in order to prepare for taking a
negative, to pull out a few inches of the film, pass the latter over
the guide roller and fix the extremity to the winding roller in the
lower magazine.
It is clear that we can have any number of magazines whatever for
carrying about, all charged, just as one carries the frames of his
ordinary camera.
Chronophotography presents no more difficulty than ordinary
photography as regards the taking of negatives, and the amateur who
has not the proper facilities for developing and printing the latter
can have these operations performed by a professional. Animate
projections are beginning to be introduced into parlors, and some day
will entirely replace the magic lantern therein. The excitement caused
by the catastrophe at the Charity Bazar is now calmed, and it has been
ascertained that the accident was not due to the lamp of the
projector, but to a carelessly handled can of ether. So the extension
of this sort of spectacle, momentarily arrested, is taking a new
impetus, which will be further aided by the apparatus under
consideration, for the description of which and the illustrations we
are indebted to La Nature.
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