592 



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 



