Page:Popular Science Monthly Volume 91.djvu/619

 Sending Wireless Messages Under Fire

Mobile wireless stations on the western front By Captain A. P. Corcoran, Late of British Army

��YOU have heard much of the amazing inventions that have been developed during the great war — inventions that have displayed not merely human but diabolic ingenuity in their effectiveness in destroying human life. There are the British "tanks," and the German gas bombs which have accounted for many a good man. But not all are of such deadly character. Side by side with these weap- ons of destruction are many of more enduring worth, and high among these rank" the motor wireless trucks, or lorries as they are called in England.

It is quite impossible to overestimate the importance of wireless in the great war, but the part that it plays differs with the character of the fighting. No army now but is equipped with wireless con- trivances. The French use the de Forest system; the Rus- sians and Italians, the Mar- coni; the Germans and Austrians, the Telefunken; and the British use two sys- tems. One is the Leyland, the other is the Marconi — the standard I X A K.W. set — fitted in a Daimler motor truck. But though they all vary in de- tails, in principle

Iron clamp to hold mast

���Captain A. P. Cor- coran late in active service in the British Army in France

��they are the same. They are alike in all essentials.

A more compact contrivance than this traveling station it would be ex- tremely difficult to find. The body of the truck is about 12 ft. by 6. The entrance, of course, is at the rear. At the far end of the car is a bench 3 ft. high by 4 ft. deep, , on which are placed the multiple tuner, the magnetic detector, the magnetic key, the operating key, telephone condenser and earth arrester. Underneath, the space is divided by a thick piece of board. On one side are placed the jigger, the aerial induc- tance, high tension condenser, slidinginductance, spark gapand transformer; while, on the other, are the rotary converter and a small dynamo, the starter and field regulator being fitted on the side of the vehicle.

Running along the truck, then on either side from door to bench, comes a locker 18 in. high by 18 in. deep. In this are stored the aerial, on£ set of aerial poles, insulators, spanners, etc. These poles telescope into 5 ft. lengths, which can be neatly stowed away, when not in use.

As these motor-trucks are designed both

as traveling and fixed stations,

it is necessary to equip

them with two

sets of

���Socket for heel of -nast

��-Socket for heel of mast ■Steel mast for a fixed station

��Multiple tuner. Detector, Transformer, Rotary, Condenser. Etc.

��A motor-truck, designed for both traveling and fixed stations, which carries two sets of aerials

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