Papebs ox Medicixe. Pxtblic He.vlth a>"d Saxitatiox 105 



pointed to make a cliemical and bacteriological investiga- 

 tion. He found that the sewage was so treated and puri- 

 fied that the water of the stream was actually less mipure 

 below the outlet of the sewer than it was above. The in- 

 junction was dissolved. Finally, on appeal to the House 

 of Lords (1912, A. C. 7S8) the dissolution of the injunc- 

 tion was sustained, but with the provision that the purifi- 

 cation must be maintained. 



Cities must purify their sewage before turning it into 

 streams. It will cost less to maintain proper Imhoff 

 tanks and other purification works than it will to pay 

 damages, and the tendency is to hold cities more rigidly 

 to these recjuirements. 



Discussiox OF Paper by Johx E. Ball 



As related to the facts stated I may mention conditions 

 at Evanston. South of Hamilton street the government 

 suiweyed land, which was taken up, which land was 

 washed away, and its location is now out in the lake. 



Opposite where Memorial Hall now stands in the 

 campus I remember a house which stood some distance 

 from the lake. I remember one day hearing a man say 

 that he had cut ten cords of wood between that house 

 and the lake, and one would not notice that any wood had 

 been taken out. All of the foundation of that house long 

 ago disappeared into the lake. It was my observation 

 that the washing out of the banks occurred during north 

 east storms, and that the gain so made by the lake was 

 kept. 



Then citizens began to build breakwaters — small piers 

 extending into the lake. These broke the force of the 

 waves, and caused them to deposit sand. Thus land was 

 made. "Wliere I remember to have seen steamers draw- 

 ing ten or twelve feet of water at the foot of Davis street 

 now there is solid land, made first by the deposit of sand 

 by the lake, and later increased by filling done by the 

 city. The city did not begin to fill in until after the lake 

 had receded. 



