Page:Popular Science Monthly Volume 92.djvu/681

 Popular Science Monthly

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��Constant Friction M^de a Freak of Telegraph Key

THE peculiarly formed knob in the picture was taken from a telegra- pher's key used continuously for fifteen years by Mr. W. C. Staib, operator in the

general offices of the ^

Lehigh Valley Rail- road at South Bethle- hem, Pa. It is true, the knob is not of stone, but of hard rub- ber, and was not worn by dripping water, but by the fingers of the operator, but, after all, the cause of the wear in the case of the stone as well as in that of the rubber knob is the same — friction.

Mr. Staib is suffer- ing from operator's cramp and can now use but one finger in sending

��Banana Fiber Bags for Raw Sugar Containers

��S^'.^

���GAR planters in the Hawaiian slands are facing a shortage of bags used as containers for raw sugar. These bags have been imported from Calcutta.

, Recently machinery

was sent to Honolulu from the State of Wash- ington for the purpose of manufacturing the bags from the fiber of banana tree trunks.

��This key was worn out by a telegraph operator's finger

��In the course of time his finger, by constant friction, wore a deep indentation in the hard rubber, nearly penetrating it. The other fingers of the operator's hand, rubbing against the edge of the knob, wore away part of it, gi"ving the knob an eccentric shape.

This is just another instance of how a constant small friction will wear out the hardest sub- stances. Everybody knows the time-honored anecdote of the way the rims of the Eas- tern wells are worn out by the soft rope. There have been many instances of the remarkable effects caused by ■-. ,.

constant friction, but that of the telegraph key is --^ unusual.

���Roller skates

��Making a Coaster From Roller Skates

DO boys like coast- ing? Just ask them, or what is even better, watch them when they have a chance to give them- selves up to that sport. Coasting on roller skates is fun, but coasting on one of the regular coasters with foot-board, steering post and brake is, next to flying, pure bliss. Emory S. Egge, of Montgomery, Ala., who invented the coaster illustrated by the accompanying diagram, has a claim upon the gratitude of the boys, for his invention will make it possible for many who could not afford high priced coasters, to indulge in the coasting sport. The device is extremely simple and can be used with any pair of roller skates. The skates are attached to two blocks un- derneath the foot- board by strap and clamps. The rear block is fastened to the footboard, and the one in front to the steering post. The brake, a plain lever arrangement, is worked through a slot near the steer- ing post.

���Homemade coaster made from board and pair of roller skates

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