The Drainage of Melbourne. 69 



localities to be so treated. Some better plan, surely, might 

 be devised. Why should certain places, " the natural direc- 

 tion of the drainage" of which is not " unsuitable/' be 

 omitted from the general system " because the sewer levels 

 would be too low to be directly connected with the main 

 sewer" ?* If one locality is too poor of itself to pay for 

 exceptional or additional measures being taken for its efficient 

 drainage, other localities ought to contribute. It would not 

 be to the advantage of the wealthier' and more favourably 

 situated localities to have in their midst imperfectly drained 

 places — hot-beds of disease, due to bad drainage. The drain- 

 age of Melbourne and its suburbs must be treated as a whole, 

 and difficulties properly met, not avoided. 



23. The openings to admit to the sewers a small quantity 

 of the dirtiest water from the streets, whenever rain falls, 

 are placed at the bottom of the street gutters. The prin- 

 ciple by which the admission of this water is to be regulated 

 requires explanation. On the one hand, the drainage of 

 streets where there is much traffic is found to be as foul as 

 the worst sewage, consequently, ample provision for passing 

 it into the sewers is necessary ; on the other hand, unless 

 the sewers are of sufficient capacity, they are liable to over- 

 flow in long-continued wet weather, and to flood low-lying 

 yards and streets. Merely trapping house drains would not 

 prevent this serious evil. Further, what is to prevent much 

 of the street grit, which the essay remarks should be ex- 

 cluded, from being washed through these openings into the 

 sewers ? 



24. Owing to the limited time allowed for reading this 

 paper, a few other points will be only just noticed by one or 

 two questions : — (1) What are the respective quantities of 

 house and street drainage the sewers are designed to carry ? 

 The only information as to the volume of sewage to be dealt 

 with is contained in the statement of the work for the 

 pumps to do. (2) Is the remark in the essay, " that the 

 sewage cannot be brought to airy filtering ground by gravi- 

 tation," borne out by the levels given on the plans as regards 

 the higher parts of Melbourne ? Owing to all sewage having 

 to be pumped, much has been excluded from the sewers that 

 might be admitted with advantage, such as water from baths and 

 from court-yards. (3) What provision is made for getting rid 

 of that portion of the subsoil drainage, which the essay says, 



* See paragraph 19 of the essay. 



