Page:Popular Science Monthly Volume 92.djvu/608

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��Popular Science Monthly

���This bicycle track, properly banked and oiled, was designed and built by a number of resourceful Los Angeles boys

��'Let's Build a Bicycle Track" And They Did

��boys in Los a very good

��AN ingenious crowd of ±\. Angeles have made bicycle track on a vacant lot. One of the boys' fathers was a contractor and this lad superintended operations. The track was first laid out with chalk and stakes, and then the bunch turned to and did the digging. They soon had it banked up and smoothed off. Then they watered it, and oiled it with waste "slag" oil which they carried from a nearby oil well in tin cans.

��How to Keep the Wind- shield Clear by Heat

TWO Chicago inventors have recently patented a device for keeping the wind- shield of an automobile or the window glass in front of a trolley motorman clear by means of an electric incandescent bulb. The heat generated by this bulb is sufficient to heat the glass so that snow, sleet, moisture or ice will at once be turned into water and run off or dry off, thereby enabling the man behind it to see through without difficulty.

Although the same in prin- ciple, the device for the automo- Vjile differs slightly from that for the trolley car. In each there is a semi-cylindrical casing enclos- ing the incandescent lamp and a Vjracket supporting the casing to enable it to be swung up out of

���the way when not in use. The uncylindrical portion of the casing consists of a flat perforated metal sur- face which is in contact with the glass of the wind- shield or car window.

The automobile unit has a bracket which is slipped over the wood or metal edging on the top glass of the windshield, in the car device, the bracket arm is pivoted inside the bottom of a box with a hinged door so that the arm and casing enclosing the lamp may be swung about its pivot into the box and the door closed. In each case, small coil springs are employed to keep the perforated metal part of the casing in contact with the glass so that the heat radiated by the bulb and reflected by the back of the casing cannot pass off without first going through the glass and heating it sufficiently to dry it.

Every automobilist knows how uncom- fortable, and even danger- ous, a frosted or misty wind- shield is, and any device that will obviate these con- ditions is welcome. This device has an advantage over scrapers and cleaners in that it requires no re- peated manipulation or attention.

��Pei-forated plate

���An incandescent lamp in a reflector melts the ice and moisture off the windshield, giving clear vision

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