SCIENTIFIC EYE

Taranaki Central Press, Volume IV, Issue 454, 11 June 1937, Page 7

SCIENTIFIC EYE

DETECTING AIRCRAFT

Remarkable Invention New York, Mt/ 11. The latest defensive .device,, the petosc.ope, the invention of.an electrical engineer, Alan Fitzgerald, is credited in scientific circles with affording greater protection against, ar rial attack In war. it detects, by an .adaptation of the famous photo-electric I eye, 'the presence of aeroplanes, whether travelling in random directions or in a predictable manner, and announces their presence by means of a signal bell or horn, which, amplified in time of warfare, could alarm a whole city. The photo-electric eye has been put to many curious uses recerl ly. It controls the opening and shutting of (doors. It operates vending end counting machines. It announces the presence of ships approaching the free port of Staten Island, New York. It detects the presence of knives, weapons or pieces' of metal in the clothing of convicts as they leave the ceil block each morning and arrive there in the evening. Demonstration to Experts. A group of [aviation experts. assembled at a Philadelphia airport assidled in recent experiments, to determine at what height and under what conditions an aeroplane could be detected. When an aeroplane from the airport came into its vision a bell clanged immediately. A small, motor-operated device was attached to tile control box of the so arranged as to wave a signal the moment the motor became energised A man stationed across the field waved a flag at intervals, whereupon pe'toseope waved its own flag. The usefulness of the new invention is not confined to out of doors. It should revolutionise factory work, such as the inspection of cloth and paper for defects. In an experiment the petoscope was adjusted to survey a roll of paper previously marked by hand to represent defects. The paper was passed by means of rollers before the machine at the rate of several hundred feet a minute. Illuminated' by .a studio lamp, the paper brought a responsive signal as each came into view. ■;l.< ' s ■ ■■ Photo-Electric Eye. , A striking use Of thephoto-electric

eye is in evidence at the first free port in It lie United States recently established here. City piers at Staten Island are being use<l as a free; zone. On half-a-dozen of these i-rtrs shippers may import, go,ods from foreign countries, process them and le-ship them without paying customs duty. Only when the goods are taken from the free zone to. another part of the country are they dutiable’. Obviously line free z.mo must be ctuefully guarded against smuggling. A 10ft. wire fence and light beams, half.a-mile long, perform this function. The lights are just above the level of New York Bay, within the two piers bounding the free pout, m each pier photo-electric eye & have been installed. Thus, when a vess: 1 or other moving object crosses the light ray between the /.wo “eyes,” an alarm sounds. These beams 'are movable and rise and fall with the tide.