Page:Popular Science Monthly Volume 91.djvu/910

 The Eagle Spreads His Wings

By Waldemar Kaempffert

��How 23,625 Ameri- can airplanes will be built at the rate of 3,500 a month to crowd the Germans out of the air

���The Liberty motor, which will solve the engine prob- lems of the air- plane, and how it will be built

��BETWEEN 1908 and 191 6 our army ordered fifty-nine airplanes and re- ceived fifty-four. In 191 6, with the possibility of being plunged into the war ever present, orders for 366 machines were placed, but only sixty-four were delivered. Even little Bulgaria in time of peace had almost three times the number of airplanes that we owned when we declared war.

And now we are planning to build 23,625 airplanes at the rate of 3,500 a month. From less than a hundred a year to over thirty times that number in a month!

Airplane building is essentially a military industry. The great French and German builders of flying machines would have starved to death had they been dependent on the general public, and this despite the rich prizes that were offered by sportsmen and despite all the interest whipped up in flying contests by the daily press. Because the airplane builder never received ade- quate support from the Government we have to create a real industry. In 1916 the American air- plane industry, such as it was, had a capitalization of only $50,000,000 and gave employment to about 14,000 men. The money invested in the airplane industry of England now amounts to $375,- 000,000; the number of employees is 66,- 000; the capacity of the plants is 41,000 machines a year. Compare these American and English statistics and it will at once appear how much ground we have to cover.

���Stitching the fabric of a stabilizing surface. Linen, for which we depend on Ireland, is used

��Unfortunately the airplane is not like the automobile. It can hardly be compared, from a manufacturing point of view, with anything in the world.

The Automobile and Airplane Compared

It does not matter very much whether an automobile engine weighs thirteen, four- teen, or fifteen. pounds to the horsepower. An automobile-engine maker can think and work in pounds; but the airplane maker must consider ounces. The airplane itself is essentially a lifting device. It must elevate and transport not only itself but a useful load. The less of itself that it has to lift the greater the load that it can carry. Sometimes it must be fast — faster than any artificial thing except a bullet. Great speed can be attained only with a bigger engine, and that means more weight.

How An Airplane Engine Is Built

To make an automo- bile engine, molten metal is poured like so much water into a mold of sand; when the metal cools the crude form of an en- gine congeals. The Liberty motor is not so easily produced; it is machined out of a solid block of steel — the very best steel that the most know- ing metallurgists can produce. The cast- ing of an automobile engine is a matter of minutes; the ma- chining of a Liberty engine is a matter of hours, even days. Automobile engines are produced by the hundred in the working day

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