﻿144 Transactions. — Miscellaneous. 



properly speaking fan wheel, as the blades in this little example are plain, and 

 not to the helical cvirve) is fifteen inches in diameter. The blades are set to 

 an angle of twenty degrees to the disc, and in a two-mile current the revolutions 

 are once per second nearly. The pistons of the pump are worked by a ci-ank, 

 and, being single-acting, propel its contents once per second. The diameter of 

 the cylinder is three-quarters of an inch, and stroke of piston 2-7 inches. 

 The quantity of water per sti-oke is therefore 1-1925 cubic inches. At the 

 above rate of speed, the quantity delivered is therefore 71*55 cubic inches 

 per minute, or 59*5 cubic feet, equal to 368-9 gallons per diem of twenty-four 

 hours. This little model would, therefore, liberally supply the wants of a house 

 of the largest class, and the first cost (not including piping) would not be over 

 fout or five pounds sterling. 



For town supply, the screw, pump, and gearing would reqiaire to be designed 

 for the population j but taking for example one of the largest force-pumps in 

 the works of Messrs. Burt, of this city, I find it to be four inches in diameter, 

 eight inch stroke, single action once per second. This pump, in constant 

 operation, would deliver 3-5 cubic feet per minute, or 5,025 cubic feet, equal to 

 31,155 gallons for twenty-four hours, which would amply suffice for the supply 

 of a town of 1,000 inhabitants. Had the water supply to be raised 100 feet 

 above the level of the river, such as would be necessary for Balclutha, 

 Alexandra, Clyde, or Cromwell, as one horse-power raises 5*28 cubic feet to 

 that elevation per minute, this power, allowing amply for friction, would suffice 

 for the above service. So, were a screw applied to the pump revolving in a 

 current of seven miles per hour, one of three feet six inches in diameter would 

 do the duty. 



The cost of the apparatus complete, delivering water at the top of the bank 

 (not including street pipes, etc.) will of course vary with the nature of the 

 position and relative facilities afibrded. Where the river is narrow, the screw 

 and pump would best be held by a wire cable stretched across the current or 

 arm of the river. Where the banks are steep and rocky, a boom secured by 

 {Stays and guys would be the best mode. Where the river is wide, a small 

 punt, or even a barrel or buoy, might be used, and so forth. Tn either case 

 the cost would not vary very much, so taking the fii-st by way of example, 

 the following is an approximate estimate : — 



50 fathoms of 3 inch galvanised iron wire rope 

 Pump . . . . . . . . 



Screw ........ 



150 feet of 2 inch india-rubber tubing at 2s 6 d per foot 

 150 do. do. iron piping, at Is. 3d. per foot . 

 Carriage and labour of erecting .... 



£ s. 



d. 



. 8 15 







. 10 







. 10 







. 18 15 







.97 



6 



. 50 







£106 17 



~6 



