ABSTRACT OF PROCEEDINGS. XIX. 



necessary resumptions being estimated at about £7,000,000. 

 Tlie estimate was based on the supposition that excavation 

 would be carried out by compressed air drills and explosives, 

 and would have concrete lining about 12 inches thick, but 

 if the tunnels were excavated by machinery, probably no 

 concrete lining would be necessary. If concrete lining 

 could be eliminated, a saving of £1,250,000 would be made 

 for that item alone. 



The question of the porosity of the sandstone was dis- 

 cussed, and whether without concrete lining, it would allow 

 the escape of water by percolation under a pressure of 800 

 feet. He quoted the Burraga Dam as an instance where 

 the water, with a head of 60 feet, passed through the con- 

 crete to the outer face. By scrubbing cement into the 

 face of the inner side of the dam, a perfectly smooth glass- 

 like surface was given to the concrete, and the trouble 

 entirely disappeared. He regarded Mr. Keele's scheme 

 for the linking up of the dams by tunnels as a very excellent 

 one, and the connecting of the head waters of the Wollon- 

 dilly to Prospect, a far better and more practical scheme 

 than what is known as the Warragamba scheme. 



He considered Mr. Keele's proposition to be of such great 

 value to the ratepayers of Sydney, that he urged the Society 

 to bring the paper under the notice of the Government, so 

 that the matter should be investigated. He concluded by 

 moving: — 



"That considering the national importance of Mr. Keele's 

 paper, the Council of this Society should consider the question of 

 personally waiting upon the Acting Premier, and asking for a 

 Royal Commission of enquiry." 



Mr. O. W. Smith, m. inst. c.e., (a visitor) considered the 

 present source of water to be inadequate to meet the 

 requirements of increasing population, and he regarded Mr. 

 Keele's proposal as a most attractive one, and thought 



