THF PROSPECT AND KENNY HILL SCHEMES. 275 
actual survey. I have recently learned that the Department has 
made such modifications as will increase the head at Crown-street 
—I am not aware to what extent; but, as the head at Prospect is 
only 170 feet, and from which must be deducted the necessary 
fall for delivery at a distance of 22 miles, the difference obtained 
must fall very short of the desired 240 feet above high-water- 
mark—in fact it can at most not be 10 feet. Not being able to 
bear testimony to the correctness of Mr. Gipps’s levels or survey, 
I feel bound to state that his estimates give me the impression of 
being cut too low ; but Ido not think it necessary for him to 
a saving in expenditure, as if the scheme is otherwise feasible 
the additional head obtained would, according to Mr. Clark’s esti- 
mate, be cheaply procured at a cost of £150,000 over that of the 
+ scheme, that sum being the present value of the cost of 
] 
In the above I will, no doubt, be held to have subordinated 
the scheme for the irrigation of the county of Cumberland to 
prunary object of the scheme was a gravitation system for 
Sydney ; secondly, that I have from an actual experiment at 
Bacchus Ma. 
all I could to have promoted their views. It has been said that 
the introduction of a higher pressure in the mains would be 
m ing them. This is true with to some of 
the mains laid in ground impre with salt ; the iron in some 
pipes in such localities has been s y - 
kind of plumbago, and the present pressure is ly destroy- 
ing them ; but the general run are the same thickness as 
Pressure obtained in the pipes—viz., the bursting of lead services. 
Y iron abichess al sie attached to the main by a length of 
x 
