128 WATER SUPPLY TO SYDNEY P>Y GRAVITATION. 



pure there that an analysis of them would be quite surperfluqus. 

 As much strain has been laid upon this subject, I desire to 

 enlarge somewhat upou it for your satisfaction. The waters of 

 that region come from the heavens perfectly pure, and from over 

 the sea. They fall on a barren sandstone country, free from all 

 mineral impurities, or at most meeting here and there only with 

 " orchry pans" of small extent, caused by the partial mixture of 

 ferruginous and peaty matter, but existing in such small quantity 

 as not to discolour the waters, and which waters are found to be 

 so clear in the waterholes around that the smallest objects are 

 plainly discernable at various and considerable depths. Knowing 

 this I should as soon think of having waters analyzed that would 

 be caught in a clean wash-hand basin from the clouds up there ; 

 neither could I propose to ascertain how many grains of solid 

 matter existed in each gallon of such truly crystal water which 

 passed through nothing but silica and light vegetable matter 

 until it reaches its storage in the lake, or delivery position at the 

 iron mains near at hand. 



Questions and doubts were also raised as to the retaining 

 capacity of the sandstone underlying the proposed basin or lake. 

 It was supposed that its porosity would endanger exhaustion. I 

 am sure that such fears are quite without cause. The great basin 

 that is at our command for the formation of the storage lake, is 

 covered with swamps all over and in every direction, on the east as 

 well as on the west, north, and south side, which marks its 

 features for retaining water ; and I am convinced that the 

 Loddon valley, if shut in by a cement concrete dam at a spot 

 marked and measured by me, would present one of the finest 

 reservoirs ever produced by nature, and available for man at the 

 least possible cost, and at an elevation (when full) of 1,171 feet 

 over the sea, and distant about thirty-two miles only from 

 Sydney. As regards the porosity of the sandstone of that 

 country being such as to endanger its retentiveness of water, I 

 should never think of such results, care being taken of course to 

 sink for proper foundation for the cement concrete dam. Per- 

 haps the best answer that can be given to such an apprehension 

 would be to inform you that the dam at Freiburg, which is quite 

 impervious, is built on and over a sandstone country of the 

 Jurassic formation called " molasse," which is likely to be more 

 porous than our coal sandstone of the Loddon country, as it is 

 from the molasse that the best stone filters are made. Neither 

 can I suppose that the cleavage of the stratifications could affect 

 the retaining qualities of this grand reservoir there. 



Having this unexpected opportunity of explaining a little 

 more of the nature of my proposals for leading the waters from 

 the high gathering ground on to Sydney, I would wish to explain 

 that, although I unswervingly advocate that the intake of the 



