Page:Popular Science Monthly Volume 91.djvu/865

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Popular Science Monthly

��849

���The five flusher-nozzles at the front of the truck swing on a vertical pivot

Exit the Old Horse Water -Wagon. Enter the Powerful Motor Sprinkler and Flusher

THE new type of mo- tor sprinkler and flusher shown in the il- lustrations above carries twice as much water as a horse-drawn out- fit, travels twice as fast, sprinkles or flushes twice the area in any given time and at three-quarters the cost. In a word it com- bines the work and efficiency of two vehi- cles. The motor-flushed or sprinkled street is better cleaned because the speed is uni- form and because the water pressure is constantly maintained at the proper point by means of the truck mechanism.

The motor unit illustrated carries a twelve-hundred-gallon tank of water which flows to a two-stage centrifugal water pump inserted into the truck drive-shaft behind the speed-controlling gearset. Thus the pressure of the water is controlled in con- formity with the vehicle's speed, so that too much is not furnished now and too little later, which happens with the horse water- wagon. The pressure is varied to suit par- ticular conditions of the street pavement by manipulation of the nozzle openings con- trolled by a lever from the driver's seat.

��The five flusher-nozzles shown at the front of the truck may be swung to flush a por- tion or the entire width of a sixty-foot street in one operation.

��Of What Use Is the Best Gun with Defective Ammunition?

SUPPOSE that a machine-gun is sup- plied with ammunition which is one per cent defective. That does not seem very serious. One per cent is such a small factor. But consider the question a bit more closely. A machine-gun fires iooo shots a minute. Defective ammunition will cause the gun to jam. It takes at least ten seconds to straighten out each jam. One per cent of iooo is 10. Ten jams, each taking ten seconds to straighten out, would require ioo seconds of work. Instead of delivering iooo shots a minute the machine-gun with the one per cent defective ammunition would be consum- ing almost two minutes in getting rid of the jams. It is evident that in two minutes' time, it would be possible for the side having poor ammunition to lose a position of great strategic value.

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