Page:Popular Science Monthly Volume 91.djvu/620

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��Popular Science Monthly

��aerials. Hence the two sets of poles. The telescopic type is the one used for mobile purposes. For the other, the set consists of a 120-ft. steel mast, made up in 12 ft.

���sections. It is carried underneath the truck.

When the latter set is to be erected, the pieces are first laid on the ground, fitted to- gether, and then raised to a perpendicular, in which position they are held by eight wire stays. The aerial, in this case, consists of eight wires, arranged umbrella- fashion, which, at- tached to the truck of the mast, touch the ground at a distance of 20 ft. from its foot.

The mobile type, on the other hand, has two sets of poles. The front pole is usually about 50 ft. high. When in position, it is fitted into a socket just alongside the driver, and is clamped to the top of the wagon, so as to be perfectly rigid. The back mast, which is also about 50 ft. long, is likewise fixed in a socket. Protruding at an angle of about 25 deg., it is supported in its place by four wire stays. Both these poles, as I have said, are tele- scopic. They are opened out by a

��One man in a motor-truck receiving station stuck to his post for thirty- nine hours without sleep or rest

��cog-wheel contrivance, operated by a handle, at the foot of the mast. They give a stretch roughly of about 100 ft. and carry four wires in parallel. Their power is derived from the truck engine which drives the dyn- amo, which in turn feeds the rotary converter.

On the retreat from Mons. during those terrible early weeks of the war, these lor- ries did wonderful work. Then everything was in a state of chaos, while General French's "Contemptible Little Army," as the Kaiser was pleased to term it, fight- ing every step of the way, was slowly retiring before the hordes of Prussians and Bavarians. All cables were cut by the terrific shelling, and fresh ones were laid only to be blown up the next minute. Then the trucks stood out, con- spicuous by their ef- ficiency. There, were just three of these motor sets in use at the time, divided among the moving infantry. Close behind the line, they kept up a constant stream of communica- tion between the fight- ers and General Head- quarters.

And how those oper- ators stuck to their pests! In the confu-

���The Interior of a French motor-truck with a soldier- operator transmitting a message in field operations

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