Salt Lake Telegram | 1933-10-05 | Page 11 | 'Invisible Eye,' Bane of Safe Cracker, Demonstrated to Delegates of Anti-Crime Conference

Invisible Eye Bane of Safe Cracker Demonstrated Demonstrated Dem Dern- to Delegates of Anti- Anti Crime Conference The invisible eye A safecracker is photographed and sets off a burglar alarm as he kneels noiselessly in front of a strongbox in a astore astore astore store office Thank the invisible eye latest eye latest scientific contributiOn n nto to aid police pollee in their never ending war against crime Dr H H. T T. Plumb consulting engineer en for the General Electric company company com corn pany demonstrated this eye and other scientific developments to police at atthe atthe atthe the afternoon session of the conference at the Elks club Thursday SENSITIZED TUBES The invisible eye he explained is the result of ot experimentation with light sensitive tubes A room may appear absolutely dark to the human eye but a photoelectric photo electric tube times times' more sensitive seas seas- tive than the e eye c of or man can detect light Burglar alarm systems have been developed using such tubes so that they are centered on a light source that that may may be c invisible to a man an intruder passes between between between be be- tween that tube and its light source the contact is broken and the result may be the ringing of a burglar alarm the flash of a camera or anything man desires Dr Plumb stated LIKE HUMAN IAN EYE These tubes work on the same principle principle principle prin prin- ciple as as a human eye according to Dr Plumb Light passing through the pupil of a eye roans falls on the retina and creates nervous ener energy If that light falls on a photo-electric photo tube it passes through clear glass corresponding corresponding corresponding corres corres- to the pupil falls taUs on a retina and creates an electric charge Shutting Shutting Shut Shut- ting off oU the light destroys the charge and can be made to operate any type of an alarm Dr Plumb also demonstrated the use of violet ultra-violet light in detecting erased handwriting and determining whether an attempt has been made to remove stains from cloth