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. 



