RAY THAT TALKS.

Auckland Star, Volume LXVI, Issue 160, 9 July 1935, Page 5

RAY THAT TALKS.

"DOOR PLEASE."

LIFE GETTING EASIER.

OPENS ANl> SHUTS YOUR GATE (Special.—By Air Mail.) LONDON, June 15. You are driving a high-roofed car into a London garage with a low ceiling. Suddenly a siren sounds, and a big electric sign flashes out "Stop! Your roof is too high." You are making loaves, tin boxes, bottles—almost anything you like—and they are passing along a conveyor belt,

Silently, without the aid of human hand or eye, they are being "watched" and counted. Now you are a burglar. Cautiously you have entered a strange house. You pass through inner doors. Suddenly bells ring, sirens blow. All because of twin magicians, a small, black box and an infra-red beam forming an Osram photo-cell amplifier. A cathode sensitive to light changes has light directed on it. When the invisible infra-red beam is broken by the passing of any solid body a circuit is broken and switches can be made to operate. The idea is being adapted for all sorts of uses. For instance: Through the door of a London factory hundreds of workmen wheeling trolleys and carrying cases pass every day. Until they fitted a photo-cell the men had to put down their burdens, open the door, and close it after they had gone through. Now, as they walk up to the door' they pass across a beam of light and the door opens and closes for them automatically.