Pre linn I nary. 



varied pari passu with the changes in atmospheric 

 temperature. 



With regard to the hourly sewage samples, I 

 do not quite imderstand why, in endeavouring 

 to estimate the strength of the sewage, such 

 an incorrect method of sampling was adopted. 

 It is a matter of common knowledge that the 

 sewage varies very considerably during the twenty- 

 four hours, both in strength and in volume, and 

 I am not aware of any insuperable difficulties in 

 the way of obtaining samples which would ap- 

 proximate very closely indeed to the real average 

 strength of the sewage. A comparison of the efflu- 

 ents and streams is given, including a short table 

 (dissolved oxygen). In each case the effluent flows 

 into a non-drinking-water stream. The view pre- 

 vails that fish are more affected by the absence 

 of oxygen than by the presence of domestic sewage, 

 either fresh or undergoing decomposition. The 

 minimum amount of dissolved oxygen needed to 

 support fish-life is about 1 cub. in. per gallon 

 (equal to, say, 3'6 c.c. per litre), and it must be 

 clear that an effluent should not in this respect 

 foul the river into which it flows. 



The above Table is extracted from Table Izzix. in " The Purifica- 

 tion of Sewage and Water," by W. J. Dibdin, ».i.o., ».c.b., third 

 edition, 1903. 



I have visited all the farms dealt with in detail, 

 Leicester excepted, and have to acknowledge the 

 courtesy that has been extended to me by the re- 

 spective engineers and bailiffs. I am indebted to 

 the engineer of the Corporation of Leicester for 

 the report giving full particulars of the work now 

 in hand. 



lO 



