Burglars’ Difficulties.

Hokitika Guardian, 4 February 1922, Page 4

Burglars’ Difficulties.

WIRELESS TRAPS. LONDON, Dec. 13. A demonstration of lmw to catch a; burglar by the use of wireless electricity was given this afternoon at Hotel Cecil. The device is an application of the wireless principle, and in-< volves the recognition of the fact that the human body has its own supply off electricity. " *

An electric “field” is thrown over a safe, a picture, an ornament, at table, a window, a curtain, or even the floor, by means of a charged wire fastened to a metal plate for better distribution. Objects to be protected! need not be conductors nor need the! wire necessarily be connected with the' object to be protected. But the wire: must be in the vicinity of the protect-i od objects. Thus a safe, for instance, lias a protective '-‘blanket” of elec-' tricity about it. A burglar approaches! it and as soon as his hand is within an inch or two of the safe the elec-* tricity from his body sets up a dis-' turbance in the electric field about the: safe. The disturbance is registered ont a small apparatus by the ringing of a bell, the lighting of a sign, the setting qff of a gramophone, or the working' of a Morse code at the police station.! Thus the owner of,a Jiopse could .have-' a bell beside his bed ring when the' burglar disturbs the electric field, or', he could have an electric sign blazoned' up across the front of his,house iirdi-i eating that burglars were within. AIF that is a matter of choice. What the' burglar does is to set these various! mechanisms in motion by bis disturb- 1 ance of the electric field.

There is no question of contact. Tlu: connexion and electric disturbance eccurs in the ether, and rubber gloves. < rubber shoes, or any other protection' is useless. Clockwork mechanism is provided, so that the alarm can be setto work at any time desired—for ex-' ample, half an hour after the bouse- ■ holder has retired .to bed—-and to remain operative just so long as noeded. It is stated bq the manufacturers that the,device will cost only a few pounds.

(The connexion between the apparatus and ,tbe : rooms or objects to be protected, consists of a thin lead-covered cable, which can easily be attached to or embedded in, the wall, and whoso intentional or accidental destruction releases the alarm at once. This connexion with the rooms or objects to be protected can be accomplished in .a simple apd non-detectnble manner, adapted to each individual case. It is possible to protect easily accessible and isolated objects of any kind. The same apparatus is useful to detect fires, as any sudden change of temperature will set up a draught and disturb the magnetic field. But tfie hanging of doors, the rumbling of cartwheels, and similar disturbances have no qffeqt.trpnn ,the delicate .instrument. In .tli© course of the discussion which :foJlo\vcd the successful demonstrations it .was pointed out that the cat might be ,qne pf the greatest troubles. This was admitted as true, and therefore it would be necessary to keep the cat, which is proverbially full of electricity, strictly in its own quarters when the machine was set. The whole idea is very ingenious and doubtless will put a serious difficulty in the way of either Bill Sikes or Raffles earning his daily bread.