When the elevated cell of the balancer was filled, its weight caused it to fall. As it fell the electric circuit of the battery V was closed. This caused the small vertical rod E to be drawn downwards by the electro-magnet F. The descent of the rod allowed the leaf L to fall. The make and break in the electro-magnet was instantaneous, so that the vertical rod E immediately returned to its normal position, with the result that, when the wing came round, after completing a revolution, it was stopped, and remained there until the second cell of the water-balancer, filling and falling in its turn, repeated the cycle of operations. As the rod carrying the wing L was the common axis of the winch and the driving mechanism of the camera the release of the wing brought the strain of the weight P upon the cord, and thereby moved the camera driving mechanism a complete revolution. Thus it conformed to the "one-turn-one-picture" movement. It was a combination of weight-driven and electrical mechanism, and, though apparently complicated and certainly cumbersome, it was satisfactory because it completed its work with unerring steadiness and regularity. As the weight P descended a very small distance for each exposure a single winding-up was sufficient to drive the mechanism for several hours. The intervals between the exposures could be varied by turning the tap on or off, thereby changing the volume of water flowing into the balancer. The thinner the water stream the longer the period required to fill the cell, the longer the interval between each see-saw, and obviously the greater the lapse of time between each exposure. Similarly the time intervals between each exposure could be shortened by turning on the tap so that the cell became filled more quickly.
By courtesy of the Marey Institute.
The Elaborate Apparatus contrived at the Marey Institute to take the First Moving-pictures of the Opening of a Flower.
(For explanation see [p. 127].)
The First Motion-pictures of an Opening Flower.
Taken at the Marey Institute. The complete opening of a convolvulus is shown in fifteen pictures.
By courtesy of the Marey Institute.