“INVISIBLE" LIGHTS

Evening Star, Issue 23498, 12 February 1940, Page 11

“INVISIBLE" LIGHTS

THE BIKKER DEVICE According to the ‘ Autocar ’ (Eng.), tho cars used by Hitler and by General von Brauchitsch, Commander-in-Chief of the German Army, are fitted with “ invisible ” Bikker headlamps, the invention of a Dutch officer. The secret of the Bikker device is that, by an ingenious system of shading, the light beam becomes so thin as 1 6 bo “ rayless.” 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, is visible for miles horizontally, and will light up an object at nearly 50yds, yet at tho same time, it cannot be seen either from the side or from above. 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, tho biggest Dutch waterway, 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. In Belgium, the controlled light is employed to sicrnal 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 darkness at 30 to 40 miles an hour, if the leading car has full Bikker equipment. A Holland-America liner has been successfully blacked-out, although all the portholes remained uncovered and the passengers had enough light to read by. Planes flying 500 ft above the ship could see the vessel but not its lights. Six warships fitted with the Bikker device were not seen at all from the air. In Britain, the controlled light has, up to now. been' used mainly for signalling at sea and for snuadron flying. Bikker lights can be employed along the edges of pavements and at crossings.