Page:Popular Science Monthly Volume 92.djvu/963

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��A Cleat for Holding Temporary Electric Wires

THE accompany illustration shows a simple means for holding temporary wiring in place. The cleat is nothing

���Glass push pins used as temporary cleats for electric light and telephone wires

more than the handy little glass push pin that can be purchased at any stationery store. It is very easy to attach, does not mar the surface of the wall and, being glass, is of course an insulator. The pin is first forced into the wall and then the double conductor cord is slipped over the head. — Edward R. Cullen.

An Electrically Driven Toy Tank That Goes "over the Top"

THIS caterpillar tank will crawl along the ground, go "over the top" of miniature trenches, plunge through wire entanglements, and push aside or climb anything that is in its path. It is a small model of the latest machines that the British Army has been using so success- fully.

Two side pieces cut from 3 4 -in. pine wood in the shape of a diamond 12 in. long, constitute the frame. At each cor- ner of the frame a roller is placed. These should be 6 in. long and 2 in. in diameter. A small nail driven through the frame

��corner and into the center of the end of the roller makes a shaft that is good enough for the purpose.

Now for the construction of the interior. Between the bottom edge of the frame- pieces a shelf should be nailed and upon this fastened the batteries and an electric motor, which will furnish the power. These should be secured with screws so that in case the tank tips over they will not be jarred out of place. Belt the pulley of the motor to the nearest roller and wire the batteries to the motor.

Over the four rollers a canvas or leather belt is laced snugly. To keep from slip- ping this belt should have several narrow wood cleats nailed upon it. A small door in the frame makes a convenient place to get to the motor in order to turn on the power, etc. It is evident that when the current turns the motor that the rollers will revolve, and, as the belt grips the ground securely because of the cleats it

���A toy tank made of wood and inclosing a motor and batteries for the power plant

carries, the caterpillar tank will crawl slowly along. The motor is of the small, toy size; from 4 to 6 in. high being plenty powerful enough. — F. E. Brimmer.

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