236 



SEWER DESIGN 



TABLE XXVII 



GREEN STREET SEWER 



growth on the sides and bottom of the pipe. Gravel of all 

 sizes placed in the pipe at the flush-tank was carried through to 

 manhole No. i in two flushes of 25 cubic feet each, the first flush 

 alone not being sufficient. The gravel scoured out of the bottom 

 of manhole No. i by the first flush was not brought to No. 2 

 until the So-cubic-foot flush was put in, and no gravel scoured 

 out of No. 2 was brought to No. 3 by any of the flushes. After 

 the seventeenth flush as above, the pipe was thoroughly scraped 

 and cleaned, and flushes eighteen to twenty-eight were made. 

 Similar results were obtained, except that the flushes carried 

 the gravel about 200 feet farther than before and seemed effec- 

 tive for that distance. 



TABLE XXVIII 



CAYUGA STREET SEWER 



