2,000 PHOTOGRAPHS A SECOND.

Pelorus Guardian and Miners' Advocate., Volume 22, Issue 66, 25 August 1911, Page 2

2,000 PHOTOGRAPHS A SECOND.

MARVELS OF THE OINEMATCK GRAPH.

Will the problem of aerial flight be' finally solved by the cinematograph ?• To the average person, perhapa,! there seems no possible connection' between the two. When it i& explained, however, that an apparatus has recently been invented which will enable cinematograph pictures to be taken at the rate of 2,000 a second, affording opportunities of fully investigating the flight of Insects, and thus arriving at a true understanding of the many problems met with in aviatidh, the value of the cinematograph to the aviator will be readily understood. | This cinematograph is the outcome of experiments on the part of a French scientist—Lucien Bull, of Paris—who has developed a most ingenious method, which greatly increases the scope of the cinemato-' graph by augmenting its speed. Whereas the ordinary apparatus takes from thirty to fifty pictures during a second; this high speed cinematograph enables as many as 2,000 views to be taken during this short interval. i

The apparatus consists mainly of a pasteboard roll bearing on its circumference a photographic film, which, under the action of an electric motor, rotates with extreme rapidity. No mechanical apparatus, of course, is able to open and close the shutter of a photographic camera 2,000 times a second. Moreover, the ordinary illuminants are far from possessing the intensity required for producing a sufficient impression on the film during so short aq interval. The inventor, therefore, avails himself of the electric spark, which unites two most essential properties, viz., instantaneous irradiating and enormous photographic efficiency. After starting the aparatus the sparks are seen to pass the more rapidly as the speed of rotation of the roller becomes higher, and each spark produces a photographic picture on the portion of the film which happens to be in front of the object being operated upon. When insects are being photographed they are allowed full liberty of movement, and are kept in captivity for a few seconds only, immediately before the operation. It is, of course indispensible that the flight of the insects he directed in such a way as to cross the field. The apparatus is therefore placed near the window, and the insects, attracted by the light, nearly always fly in the same direction.

A more serious difficulty consists in the fact that it is indispensable that the release of the shutter should take place at the precise moment when the insect crosses the photographic field, the rapid release by hand being almost impracticable. One system, which is satisfactory with dragonflies and ordinary flies, consists in keeping the insect captive by piecing one of its legs in an clectro-magnctic tweezer inserted in tbs circuit of the shutter. At the instant when the windows of the shutter are uncovered the tweezers open and the insect flics toward the photographic field.

In the case of bees and other trisects which hesitate before taking to flight, and which nearly always fly after the shutter has worked, Mr. Bull makes the insect itself close the circuit of the shutter at the exact instant of its flight. With this 'object the insect is placed in a glass tube, cut on the slope at one end and turned toward the light. This end is partly closed by a small, very light mica door, kept closed by a very delicate spring, which in its state of rest completes the shutter circuit. , When the insect has been placed in the tube at the free end, the operator waits to close the circuife of the shutter until the insect commences to railse the mica door, and consequently to arrest the flow of the current. When the insect flies away the mica door falls, the current is closed, and the shutter works sue-; cessfully.—"Tit-Bits.”