Fig. 9.—The ingenious radio-cinematographic apparatus devised by Monsieur M. J. Carvallo.
A.A. Film spools. B. Crookes tube. C. Frog being radiographed. D. Coil. F. Film. F. Clock.
G. Exposure interrupter. H. Change-speed gears.
By this gearing system it was possible to vary the speed of the camera from 30 revolutions per second to one turn in 15 seconds. When still slower speeds were desired, upon the one-turn-one-picture principle, the motor was cut in and cut out intermittently so that the exposure could be varied from once in 20 seconds to once in an hour or more. Of course, in those instances where the exposures only needed to be made at relatively prolonged intervals, the driving motor was started up intermittently so as to move the shutter at the required moment. A pendulum clock was introduced into the electrical circuit, together with a novel relay. The clock-face was provided with a ring around the dial, with the hour intervals represented by contacts instead of figures. The clock was fitted with one hand only. One electrical lead was connected to the contact ring and the other to the pivoted end of the clock-hand. When the latter came against one of the contacts the electrical circuit was completed, the motor was set in motion, and the camera mechanism was given one turn—sufficient to make an exposure and to jerk the film forward the desired distance through the gate for the next exposure. Obviously this clock system is capable of variation as desired. The contacts may be disposed to coincide with intervals of a second, a minute, an hour, or more between successive exposures. It was necessary to ensure that the contact was of sufficient duration to complete the cycle of camera movements, and, on the other hand, to prevent the motor movement being so prolonged that more than the requisite exposure and movement of the film would be made. This was effected by means of a brake, which arrested the movement of the motor after the exposure had been completed.
| I | II | III |
By courtesy of the Marey Institute.
Radio Moving-pictures of Cold-blooded Animals made by M. J. Carvallo.
I. The stomach and the intestine of a trout (one exposure every 20 seconds). II. The digestive organs of the frog (one exposure every 2 seconds). III. Lizard digesting its food (one exposure every 90 seconds).