Page:Popular Science Monthly Volume 92.djvu/299

 Popular Science Monthly

��A Sled Driven by a Motorcycle Engine and Airplane Propeller

ANY one who possesses a motorcycle or Ir\ has access to a motorcycle engine, can make use

���Details of the sled runner, top and frame that supports the shaft and propeller

��Top of sled

��L

��of it to good advantage for the winter months by u s i n p its power to drive a sled. While the power may be applied to the driving wheel that has spikes for pushing the sled, it may also be used to drive a propeller, similar to that of an airplane, which thrusts the sled forward with air pressure. The illustration shows such a power sled.

While the plans give only general dimensions, they are suggestive of an arrangement to hold the engine and its connections to the propeller shaft. The size of the en- gine and the sled will determine the size and height of the standards.

In constructing the sled shown, the power plant was fastened to the rear end of the frame, which is about 9 ft. long and 3 ft. wide, constructed

of boards about 6 in. wide and II/2 in. thick at the edges; and cross braced with boards 1 in. thick. The runners of the sleds are 4 ft. long. — Geo. M. Fox.

��288

Qualities of Steel and Wrought Iron for Plumbing

STEEL and iron pipes corrode, but tests show that steel pipes corrode far more quickly

���Reae view Side view

An airplane propeller driven by a gasoline engine is the new motive power for this sled

��is greater for wrought iron, cates that the more quickly.-

��than those made of wrought iron. The metal used to make steel pipes is a low carbon steel, which resembles wrought iron in softness, except that it has more ten- sile strength and is purer in quality. It is the lat- ^ ter charac- teristic which makes it cor- rode more quickly than wrought iron. Wrought iron con- tains slag, which ^s a glassy product. This delays the corrosion to some extent. Wrought iron pipes have lasted more than twenty-five years, if properly pro- tected from frost, while the steel ones corrode very quick- ly by the action of the chemicals con- tained in ordinary hydrant v.ater.

Acid and alkali

tests show that

steel pipes corrode

more quickly in

salt water than iron

pipes. In fresh

water, the corrosion

the steel pipe than the

An acid test also indi-

steel pipe is eaten away

-W. S. Staxdiford.

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