Page:Popular Science Monthly Volume 90.djvu/557

 Popular Science Monthly

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��objection to the type; for on soft or muddy roads the wheels may sink so that the axles rest on the ground and the car may stall, although the great power will still turn the wheels.

Another type is a lighter car built on a rear wheel drive, one and one-half ton truck, equipped w4th steel wheels and airless tires and capable of running forty miles an hour. Having but one turret, the weight is reduced to about. ^ nine thousand pounds. It has not the power to maneuver on bad ground that the heavier car has, but is probably better fitted for all-round service in the United States.

Still another type follows the lines of that just mentioned, but is built on a touring car chassis by a private company. The weight is about six thousand pounds. The "bridges" carried on each side for crossing trenches form a novel feature. There are a number of other features reflecting European exper- ience. In case of war the majority of cars would probably be of the general type of this light high-speed car. The light truck shown at the bottom of the preceding page is not in any sense an armored car, but is interesting as showing what was done to carry National Guards machine guns on the border. Each regi- ment was given five trucks in lieu of the pack mule equipment of the regulars. Four each carry one machine gun and ammuni- tion, and the fifth, spare parts and supplies. A ten-gallon water tank is carried under each body on account of the scarcity of water which the troops encountered in the border service. In action the trucks are left under cover and the guns and ammuni- tion carried to the firing position by hand. The "caterpillar" type tractor is being ex- tensively experimented with to replace horses for drawing the heavier field guns, each tractor doing the work of sixteen horses. As these tractors may come under fire, certain vital parts will be armored. More powerful tractors of this general type were doubtless the basis of the English "tanks,"

����A light-weight type of high speed for general service which has received high endorsement

��A model built on a touring car chassis by a ^private company

but the little forty-five horse- power tractor shown in the photograph on the left is only expected to do light service, principally to transport the army guns and ammuni- tion in record time wherever they may be needed and in spite of unfavorable road conditions.

��How the Submarines Got Their Peculiar Names

EVERYONE knows what submarines are, and what an important factor they have become in modern naval warfare. Their nomenclature is rather interesting. In the United States Navy the first of these crafts were named for various kinds of fish and reptiles, and we had such odd cognomens as "Adder," "Moccasin," "Pike," "Stur- geon," "Shark," "Carp," "Haddock," etc., on the naval lists. Before this list of piscatorial names ran out the system was changed, and designations of A-i, A-2, B-i, B-2, etc., down to the more recent submarines au- thorized in 1 91 5, known as the O class. In general, the numbers applied correspond to the particular lot in which they were constructed, and the letters closely follow the number of years since they were first built. In Germany they are all known as U-boats, the U being ^ the first letter of Unterseeboot, meaning submarine.

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