THE PROSPECT AND KENNY HILL SCHEMES. 279 
against my proposed modification of the Prospect scheme. It has 
been contended—l. That owing to the side and base of the 
i 
the Prospect. 3. That a gravitation scheme from Bull’s Hill 
reservoir has already been rejected by the Commissioners, owing to 
the expense of iron piping. 
Tn answer to the first objection, I would point out that the 
physical and geological character of the country of the Prospect 
reservoir is nearly identical with that of the Kenny Hill reservoir, 
so that to admit of the correctness of the above deduction we shall 
have to assume that 5 miles of canal will be sufficient for settle- 
ment purposes. But experience in our river system has proved 
that the water in some of those which have as low a fall as 1 foot 
becomes muddy, and at times undrinkable or unfit for any domestic 
purposes, owing to heavy storms 60 or 80 miles higher up the 
stream. Supposing, however, such a desirable condition could be 
guaranteed by allowing the water to flow through an open canal, 
it must then be admitted that the accumulation of sediment in 
the bottom of the canal would necessitate its constant cleansing ; 
and I think it must also be allowed that there is, in a sanitary 
ance. 
thr patient investigations of Professors Krupp, Kolbe, and 
Pettenkofer, that cholera, dysentery, and yellow fever are propa- 
gated through : : bart sania ioe 
alding trefaction of the various 0: 
stances, both animal and vegetable, which it would be ble 
to keep out of an uncovered conduit. In answer to this 
