38 PROCEEDINGS OF THE CANADIAN INSTITUTE. 



feet per second, for instauce on Gerrard street. Now what will be 

 the inevitable result 1 The sediment and solids that are held in sus- 

 pension while being rapidly whirled along Gerrard street at the rate 

 of seven feet per second will immediately begin to subside when tliey 

 reach the outlet pipe, and the velocity is reduced to five inches. The 

 pipe will be choked and perfectly useless. What is needed is some 

 means of keeping this outlet free and clear. I will explain my 

 method for accomplishing this end, adopting the first sclieme, namely: 

 A high-level and a low-level sewer, and a connecting line down say 

 Parliament street. I would have it, after passing Front street, turn 

 to the east, pass under the bed of the Don (new mouth) to the angle 

 formed by its bottom with the eastern bank, then follow this angle 

 down as far as the river needs, dredging thence easterly and continue 

 out to deep water. Th'i object of this diversion is to interpose the 

 waters of the Don between the discharge of sewage and the intake of 

 water. This would give perfect security from contamination of the 

 water su])ply. Along the line of the connecting sewer, somewhat to 

 the south of King street, I would have a flushing tank situated, 

 capable of holding say 400,000 gallons of sewage, arranged to dis- 

 charge itself automatically wherever the sewage rose to a certain 

 height. Now, estimating that one-half, 6,000,000 gallons, is collected 

 in the high-level intei'cepting sewer, and passes out through the flush- 

 ing tank, it would fill and discluu'ge fifteen times in the twenty-four 

 hours with a velocity of from 5 to 8 miles per hour, sufficient to 

 sweep along whole bricks, stones, or cannon balls, aud deliver them 

 safely into deep water. Now considering that the entire system, as 

 herein briefly described, can be constructed for about tlu-ee- fourths of 

 a million dollars, why should the ])eople of Toronto throw away one 

 and a half millions on a worthless scheme when they can get an efii- 

 cient one for half the sum ? 



Mr. Kivas Tully thought that the Canadian Institute and 

 the citizens of Toronto were much indebted to Mr. Clark for 

 the clear way in which he had placed the subject before them. 

 As to the difficulty in Tully and McAlpine's plan that Mr. 

 Clark had referred to, he would see that it had been obviated. 

 Mr. Tully showed how the dif^culty was removed by an 

 hydraulic slope. Any obstructions would be swept away into 



