October 22, 1886. 



SCIEJSrCE, 



373 



facturing establishments of Birmingham, England. 

 The air will be compressed at a central station, 

 and supplied through street mains, much as gas 

 and water are now distributed, taking the place 

 of steam for driving engines. Steam has long 

 been distributed from a central station in this city 

 with economy and safety, and there is no reason 

 why compressed air should not be distributed in 

 a similar manner. The Birmingham company, 

 which has charged itself with this enterprise, will 

 begin operations with a plant capable of supply- 

 ing fifteen thousand horse -power, six thousand of 



single-acting air-compressors, capable together of 

 delivering two thousand cubic feet of air per 

 minute at forty-five pounds pressure, will be driven 

 by each engine, making a total capacity of thirty 

 thousand cubic feet per minute. Six million gal- 

 lons of water per day will be required for the boil- 

 ers and condensers. 



The street mains wUl be of wrought iron, laid 

 in concrete troughs with "removable covers, not 

 far below the sm-face of the street. Valves will 

 be fixed at intervals in the mains, to automati- 

 cally shut off the air in case a section of pipe 



POWER DISTRIBUTION BY COMPRESSED AIR, IN BIRMINGHAM, ENGLAND. 



which have already been contracted for. The 

 accompanying illustration shows the district 

 covered by the first plant, the darker portion being 

 that which will be first sui^plied with power. This 

 area will require about twenty-three miles of mains, 

 ranging in diameter from seven inches up to 

 twenty-four. The central station is located be- 

 tween a railroad and a canal, so that coal and 

 water are readily obtainable. The coal will be 

 converted into gas, which will be then used as 

 fuel under the boilers, of which there will be forty- 

 five,- supplying steam to fifteen triple expansion 

 engines of one thousand horse-power each. Six 



should burst ; the same valves serving as stop- 

 valves, which can be closed by hand, if desired, 

 through man-holes in the street. The compressed 

 ail- delivered to customers will be measured by 

 meters, and charged for by the thousand cubic 

 feet, a special device in the meter compensating 

 for any variations in pressure. The total amount 

 used will be registered on a dial at the central 

 station by electric apparatus. 



A paper upon the Birmingham compressed air 

 scheme was read before the British association on 

 Sept. 8 by Mr. J. Sturgeon, in which he showed 

 that the large number of engines of moderate 



