LXXXVI. DISCUSSION. 
readily to replace them. The silting up of the Maroondah 
dam would be deferred indefinitely by the construction of 
these retarding dams on the upper part of the catchment 
area, but the débris carried down by storms from the 
thickly wooded area would be arrested and prevented from — 
passing into the aqueduct, and the water having undergone 
a process of sedimentation in the big reservoir would be 
supplied to Melbourne of better quality than at present. 
DISCUSSION. 
THE WATER SUPPLY oF SYDNEY, PAST, PRESENT 
AND FUTURE. 
By T. W. KEELE, M. Inst. ©.E. 
17th June, 1908. 
Mr. NORMAN SELFE said, in the first paragraph of Mr. 
Kkeele’s most interesting paper he states that the subject 
will no doubt afford ample scope for discussion. While it 
is not the general rule to discuss the addresses of retiring 
chairmen, it was certainly true that in the present case, 
the author had opened up a subject on which there was 
very much in addition to be said and in danger of being 
forgotten. He therefore, proposed rather to supplement 
than to discuss if the meeting was agreeable. As the 
paper opened with the history of the tanks and Tank Stream 
he (Mr. Selfe) thought it might not be generally known 
that among the many pictures of early Sydney, there was 
one published in London, at the beginning of the last 
century, which actually showed these tanks, and he had | 
intended to bring it in to the meeting, so that members 
