WONDERS OF PHOTOGRAPHY.

Ashburton Guardian, Volume XXXIII, Issue 8832, 7 May 1914, Page 6

WONDERS OF PHOTOGRAPHY.

Captain F. H. Behr, of the American Coast Artillery Corps, worked out the j'following method as the most practicable:—A delicate screen, formed of electrically-charged wires, is placed in the muzzle of the mortar, or rifle which is to bo used in connection wjth the -test. Other wires are attached <to this screen, and the camera is trained «n tho place where it is calculated the shell' will be when the shutter clicks. As the speed of the projectile is a known quantity, being dependent on tho strength of the charge, this is a simple problem of mathematics. Upon the firing of the gun the shell breaks the screen and completes the circuit. thu4' flashing the eye of the camera «peri for the fraction of a second necessary, to record the flight of the projectile. By regulating the v current and Che speed of the electric motor, it has lieen found possible to catch shells Just as they leave the mouth of the gun, suspended in mid-air, or as they strike the target. In the latter case the screen which regulates the shutter as placed in front of the target instead of inside the gun itself.