"INVISIBLE" LIGHTS

Waikato Independent, Volume XL, Issue 3664, 6 February 1940, Page 7

"INVISIBLE" LIGHTS

CANNOT BE SEEN FROM ABOVE PROTECTION FROM AIRCRAFT I Breukelen, January 4. In this picturesque Dutch village just behind the water line, which gave its name to New York's suburb Brooklyn, a new war industry is rapidly growing up. This is the manufacture of lamps which give an "invisible light." •#< The Dutch Government has been so much impressed by this invention of Capt. Bikker, an officer in a mechanised unit of the Dutch Army, that Holland's many waterways have all been equipped with it. The police, fire brigades, hospital's and factories are adopting it as the only form of illumination which is invisible from the air. The secret of the Bikker-device is that, by an ingenious system of shading, the light beam becomes so thin as to be "ray-less." An invisible beam is thus thrown which only illuminates the object on which it is directed. This controlled light, when installed on the bonnets of cars and beside their rear lights,* visible for miles horizontally and will light up an object at nearly 50 yards, yet it cannot be seen either from the side or from above. On Hitler's Car. The Dutch Admiralty has made an exhaustive examination of the system. By way of test every signal light, dock lamp and buoy on the Nieuwe Waterweg, the biggest Dutch watei--v/ay ,was equipped with a Bikker shade. A 'plane went up on a moonless night and was unable to find the waterway. Other tests were made with equal success, and as a result the Admiralty has ordered that every ship, every sluice and canal, and even the coastal lights should be shaded in this way. (Not only the Dutch have taken advantage of this invention. Hitler's , car. is as * Commander-in-Chief ; of the German Army. In Belgium the controlled light is employed to signal 'planes taking off at night. In Holland it is used on army aerodromes and in watch-towers. Army cars in Holland can drive in column through the darwness at 30 to 40 miles an hour, if the leading car has full Bikker equipment. Ufged by Britain.

A Holland-Amerika liner has been successfully blacked-out, although all the port holes remained uncovered and the passengers had enough light to read by. 'Planes flying 500 feet above ship could see the vessel but not its lights. Six warships fitted with the Bikker devise were not seen at all from the air. ilt is understood that in Britain the controlled light has up »to now been used mainly for signalling at sea and for squadron flying. •Bikker lights can be employed along the edges of pavements and at crossings. A Bikker reading lamp set in the window of a house cannot be seen from outside even if the curtains are not drawn. Since the Bikker system is simply one of shading it can be adapted to all forms of illumination.