14<2 On the Water Supply of Sydney. 



inches on the wheel. They are stopped, however, on an average 

 about sixty-four hours every month from this cause. 



The pumps are common double-acting force-pumps, having a 

 stroke of six feet, worked by cranks attached to the axles of the 

 paddle-wheels. The height to which the water is forced is 92 

 feet, and the most substantial work is necessary to insure the 

 etability of the pumping apparatus, under the pressure of a 

 column of wrier of so great a height." 



Having constructed a suitable dam and waste weir, it will be 

 necessary to construct a canal to the south end of the weir, with 

 sluices opening only to the estuary (similar to those in the 

 Cooks' River dam), to let out any salt water that may remain 

 above low water level within the dam. 



3. Before proceeding further, it will be necessary to show 

 that the present average quality of the water to be obtained from 

 the watershed is unobjectionable ; and this will at once appear 

 when we consider that although the water from the Wianamatta 

 shales may be objectionable, the area they occupy is probably less 

 than one-fourth of the whole area. This would reduce the 

 average hardness of the water from 8' to 3". which is preferable, 

 on the whole, to absolutely pure or soft water, on account of its 

 aniiputrescent Qualities, and its less rapid solvent powers when 

 acting upon organic matter, with which all waters are brought 

 into contact. 



One-half of the water now used in London comes from the 

 Thames, and, according to Professor Brande, is of an average 

 hardness of 15", which is not considered objectionable in any 

 way. I learn from The Builder, of July 3rd last, that, on the 

 24th 12-66, a Boyal Commission was appointed to inquire fully 

 into the water supply of London and other towns. * * * 

 The report of the Commissioners, dated, June 9th, 1869, has 

 just been presented to Parliament. In speaking of the proposal 

 to bring soft water from the heads of the river Severn by Mr. 

 Bateman's grand gravitation scheme, they say — ' The quality of 

 the water would be satisfactory as regards purity, but in point 

 of softness and colour they consider that it might prove less suit- 

 able for the supply of the metropolis than the harder water at 

 present used.' Again — 'As to the quality of the water supplied 

 by the water companies, they pronounce that the weight of evi- 

 dence is in favour of its general good and wholesome character ; 

 that for drinkmg purposes it is quite unobjectionable, and in no 

 way prejudicial to health, more especially as hard waters were in 

 evidence declared to be more free from certain dangers inherent 

 in soft waters on account of their great solvent powers.' Having 



