Popular Science Monthly 



855 



This mirror 

 placed on the 

 outside edge of a 

 garage ramp en- 

 ables a car driv- 

 er to see round 

 the corner or be- 

 hind him. He 

 can note the 

 approach of an- 

 other car from 

 either direction 



A framed mirror 

 set at the edge 

 of a road run- 

 ning through 

 Denver's Moun- 

 tain Park. It 

 enables automo- 

 bilists to see 

 any one coming 

 around a very 

 dangerous curve 

 in the roadway 



Is the Coast Clear for Your Car? 

 Look in the Mirror and See 



EVERYONE who has ever driven an 

 automobile knows how often danger 

 lurks just round the corner. A man who 

 had often longed for the ability to see at the 

 same time round the corners ahead of him 

 and what was coming behind him devised a 

 method of arranging a mirror so this could 

 be accomplished. 



By placing a large framed mirror on the 

 outside edge of a curved road or a curved 

 ramp the driver of an automobile approach- 

 ing the mirror in either direction is enabled 

 to see whether there is danger ahead or 

 behind. 



The mirror must be large enough to serve 

 the purpose and must be held in a stout 

 frame. If the frame is strong enough, 

 ordinary shocks will not injure the glass. 

 Such mirrors placed at dangerous curves on 

 highways would greatly reduce the number 

 of accidents which are always the toll 

 exacted by sharp curves. 



Two Billion Paving Bricks a Year 

 From Furnace Slag 



AT a meeting of the American Ceramic 

 ■. Society, Mr. J. B. Shaw of Alfred, 

 N. Y., told of some very successful tests he 

 had made in producing paving brick from 

 blast furnace slag. These bricks are worth 

 about $35 per thousand. They may be 

 successfully made of almost any blast 

 furnace slag at a cost of five to seven dollars 

 per thousand. He figures that there is at 

 present available about 16,000,000 tons of 

 slag annually in the United States after 

 leaving 2,000,000 tons for cement manufac- 

 ture. This would provide about two billion 

 bricks for permanent good roads every 

 year — say for laying 1,000 miles annually 

 of fifty-foot road. 



The oft-repeated attempts to solve this 

 problem seem to have met success now. The 

 slag must be treated hot as it comes from the 

 furnace and the brick must be heated out 

 of contact with air or steam lest it become 

 brittle. — Ellwood Hendrick. 



