Aug. ^,190^.'] A ffriculkiral Gazette of J^.S.TF. 621 



" It will be seen from the above table that there are inconsistencies in the 

 pressure, as there are in the flows from artesian bores. It is generally, but 

 erroneously, thought that the greater the pressure the higher the water rises 

 above the surface, and that so in proportion is the flow greater. This is not 

 the case. The discharge depends upon three factors: (1) the pressure under 

 which the flow takes place; (2) the depth, diameter, and conditions of the 

 bore itself; and (3) the nature and character of the stratum in which the 

 flow is obtained. The ascertaining of (1) is an easy matter; (2) is, of course, 

 known in the sinking of the bore ; but (3) cannot be directly known. For 

 instance, the flow from a thick seam of low porosity might be equivalent to 

 a thinner seam of greater porosity. A bore with a very low flow — say, 

 30,000 gallons per diem — when closed might indicate a pressure of 150 lb. to 

 the square inch, and, owing to the low porosity of the water-bearing stratum, 

 which must certainly control tlie volume discharged, might take considerable 

 time to reach this pressure. Another bore might have a much greater flow — 

 say, 1,000,000 gallons — but, owing to the high porosity of the stratum, and 

 a constantly free flow when closed, show a pressure of only 50 lb. to the 

 square inch. Take, for example, two bores of equal diameter and pressure, 

 but with different thicknesses of water-bearing stratum, of equal porosity, 

 it is evident that the bore which penetrates to the thicker stratum must 

 have the greater discharge. With variations, subject to conditions, there is 

 a workable pressm-e fi"om all flowing bores. 



" Where power is to be derived from the higher pressure of artesian bores, 

 or an extremely liigh fall, the use of the ordinary impulse and reaction turbine 

 is rendered impossible — the one because of the enormous stresses which 

 would be set up in the machinery; the other because of the prohibitively 

 high speed which would be developed. With such bore pressure, or falls, 

 an engine of the simplest construction is desirable, and one in which a 

 reasonably high speed is obtained \vithout undue strain on the working parts. 

 Such a form of engine is found in what is known as the Pelton wheel, if this 

 be intelligently designed. The engine consists essentially of a stout wheel, 

 upon the periphery of which a number of specially shaped buckets, or vanes, 

 are secured. The wheel is rotated by the impulse of the rapidly moving 

 jets, working tangentially against the lowermost vanes, and the power 

 developed is conveyed through the shaft. The power is regulated by a shding 

 valve, or sluice, behind the nozzle. The action of the vane, or bucket, on 

 the wheel is to divide the jet into two equal parts, each of which ghdes over 

 the curved surface of the vane, and is deflected backward until it is discharged 

 from the wheel with practically no velocity. 



" In falling water, the water in a state of pressure from gravity, is led 

 through nozzles into the vanes of the wheel. In artesian flows, the water is 

 hkewise led through nozzles into the vanes — also in a state of pressure due 

 to gravity of the body of water held in the water-bearing rocks lying above the 

 level of the bore site ; so that, in practical effect, there is no difference between 

 the two sources of supply, the final apphcation being in both cases the same. 



