Page:Popular Science Monthly Volume 91.djvu/871

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Popular Science Monthly

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���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.

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