Page:Popular Science Monthly Volume 88.djvu/421

 Popular Science Monthly

��393

��A Steel Hill to Test Automobiles

THE al)ility of a motor car to climb a hill "on high" has long been con- sidered a necessity by motorists and a selling argument by manufacturers. And because Detroit, where many motor cars come from, is in a flat section of the country where hills are the excep- tion, one manufacturer has built the steel test-hill illustrated. Furthermore, this same manufacturer has also con- structed a half-mile track for speed tests and what is termed a "sand pit."

��The Noisy Motor-Boat and the Unabashed Fish

CONTRARY to general opinion, a number of motor-boats cruising about a harbor with more or less noisy engines have no appreciable effect upon the fish in nearby waters. It has long been thought, particularly by fishermen, that the presence of a noisy motor-boat would drive the fish away. Exhaustive experiments recently conducted by the Bureau of Fisheries prove this theory to be incorrect.

���Detroit automobile dealers had to build this steep hill to order so as to have grades where they could demonstrate the hill-climbing proclivities of their cars in that city of level highways

��The track permits speed tests, and in the "sand pit" the testers alternately sink the cars to the hubs and then drive them out of the clinging sand.

But the test hill is perhaps the more remarkable. The hill is located in the center of the speed track and is built entirely of structural steel. It is five hundred and forty-two feet long and thirty feet wide. The two approaches have grades of varying steepness so that cars can be tested on gradual and steep inclines.

The speed track is built of wood, more than two hundred and fifteen thousand square feet of lumber being required. It is built on a foundation of clay and cinders with the turns banked and is surfaced with pine plank- ing, creosoted to afford a dustless sur- face for the tests.

��In testing the effect of motor-boat noises, on fish, a number of young scup, known to be sensitive to sounds, were placed in a large wooden cage. This cage was fastened in quiet water at the end of a wharf, and a motor-boat with a very noisy engine was run at varying distances past the cage. At no time did the fishes appear to be dis- turbed by the noise, except when the splash from the boat hit the cage. Then the scup would generally dive to the bottom of the receptacle.

Another test was made with baited lines. When a number of fish had com- menced to nibble at the bait, a motor- boat was backed up under its own power until its stern was directly over the lines. The fish continued to nibble until driven off by the backwash from the propeller.

�� �