WATER SUPPLY TO SYDNEf BY GRAVITATION. 101 



tunnel of 3 miles and 35 chains would be all through compact 

 sandstone, and would be only one-third of the length of tunnelling 

 planned for the Nepean water scheme along its course of 03 

 miles. 



I would also add at this part of my paper that the watershed 

 that Avould be commanded by my scheme would be of a nature 

 that it would be impossible to compute the area of until a most 

 expensive survey was continued to the south from the proposed 

 Loddon dam. But this much may be asserted without hesita- 

 tion, — that the watershed available for the whole project would 

 be far in excess of requirements, as all the countries to the south 

 of the proposed Loddon dam and tunnel above the levels of 1,121 

 feet, and up to 1,300 feet, say for a course of quite thirty miles 

 (allowing 6 feet fall to each mile), would command an enormous 

 watershed from a country which rises 40 feet to the mile all the 

 way to the Bong Bong Mountain, near Shoalhaven. Practically 

 the watershed that my scheme would command would absorb 

 nearly all the supply waters of the Nepean water-scheme, besides 

 absorbing the head sources of the Greorgcs River watershed ; 

 and without drawing upon the Port Hacking large supply waters 

 at all, but which could be made use of by my plan it* wanted. 



Under my present project for the supply of {Sydney, I desire 

 to say that I am confident that an excessive quantity of water 

 would be supplied for a much larger demand than Sydney now 

 requires, without extending the south channel further than to be 

 able by it to divert into its course all the upper sources of the 

 Cataract River, the falls of which are bounded by the coast range 

 on the east, and by the high level track or road which passes 

 from Wollongong by Mount Kiera on towards Appin. 



I also wish, by this Society, to place my remark on record 

 that should Sydney, in times to come, so increase as to become 

 one of the largest cities in the world, future generations need 

 never fear a short delivery into the city, because it will be found 

 that they could continue my proposed channel under the above- 

 named Mount Kiera .Road by a short- tunnel of less than half 

 a mile, and about 200 feet below that part of the Mount Kiera 

 aud Appin Road, where I made it 1,400 feet over the sea, and 

 exactly where such tunnel would have to penetrate the ridge 

 which divides the Cataract from the Cordeaux waters. This 

 being done, the channel could continue for miles and miles on 

 the western slopes of Mount Kembla, and on and on for perhaps 

 30 miles by its own necessary elevation of from 1,200 to 1,300 

 feet, along a country which rises constantly on an average of 40 

 to 41 feet to the mile south. Along such course there would not 

 be any deflections towards the coast to interfere with the onward 

 progress and success of a south to north aqueduct. Such channel, 

 aided by storm dams here and there, might be made to lead an 



