in the City of Melbourne. 3 



found that the maximum quantity discharged on that 

 occasion was between the hours of 9 and 10 a.m., on 

 the 11th February, when it amounted to no less than 

 9,204,381? imp. gallons, and the damage to private property 

 in Elizabeth-street alone to i?2,500 ; the rain gauge on 

 that day indicated a fall of 3.42 inches, which when com- 

 pared with tiie previous calculations, after allowing for 

 absorption and storage over the superficial area drained, 

 approximates so closely as to become strong corroborative 

 evidence of its accuracy. 



Some idea of the force of the stream may be formed from 

 the fact that a piece of freestone weighing 38 pounds was 

 washed or carried away from the front of the then new 

 building at the corner of Elizabeth and Collins-streets, and 

 immediately opposite to Mr. Cashmore's, and deposited a 

 little above the New Bank in Elizabeth-street (English and 

 Scottish Chartered.) 



To obviate or prevent these excessive floods has been 

 my aim for many years, and 1 have repeatedly suggested, 

 what I consider the best method of doing so, namely, 

 to arrest the water at a given point, and at a given level, 

 and to carry it off by a tunnel, and so prevent it from 

 entering the town. 



When I made the survey of the area drained by the five 

 several outlets from the City-proper in 1864, I shewed 

 upon the plans, one of which I now exhibit, that the 

 drainage from about 547 acres might be thus arrested, and 

 the total area reduced from 956 to 409 acres, with the 

 following effect : — 



In Elizabeth-street only one-fourth or 25 per cent, would 

 be discharged at the outlet ; and the result of this relief at 

 Lonsdale-street would be that, instead of 83 per cent, of the 

 total quantity of water discharged at the outlet passing 

 Lonsdale-street, there would only be about 8 per cent. At 

 the Post Office, 14J per cent., instead of 89 J per cent. ; at 

 Collins-street, 20 per cent., instead of 95 per cent. ; and at 

 the outlet in Flinders-street, 25 per cent., instead of the 

 whole quantity, as before stated. Swanston-street (at its 

 intersection by Bourke-street) would be relieved of no less 

 than 85 per cent, of the water which so frequently renders 

 this part of the city impassable to foot passengers. 



Although I have made careful observations of the height 

 to which the water rises in the street-channels, I have 

 been, and I am at present at a loss to know what quantity 



b2 



