The Drainage of Melbourne. G3 



sewers, (3) recommending the introduction of water-closets 

 in place of the dry-earth system, (4) the selection of a site 

 for the final disposal of the sewage, and (5) dealing with the 

 sewage by the system known as " intermittent downward 

 filtration/' But even on these points the information is very 

 meagre, and the data on which the results generally are based 

 are not given ; it is, consequently, often very difficult to 

 make out what the essay really allows for various purposes. 



9. In criticising the essay it will be well to commence with 

 the estimate of probable outla}^ for the works, which is one 

 of the first things to attract the attention of the public, who 

 will have to find the money. The estimate cannot be 

 criticised in detail, but the total sum may usefully be com- 

 pared with the cost of works executed elsewhere. The cost 

 of the main drainage of London was " £1, and its annual 

 expenses Is., per head of the population ;" and it has been 

 remarked that "these figures contrasted most favourably 

 with the prime and annual cost of any other system in use," 

 in England or elsewhere.* The drainage of Paris probably 

 cost about £2 a-head. f It would not be surprising, therefore, 

 if a complete and efficient scheme for Melbourne should cost 

 more than stated in the essay ; the ultimate cost allowed 

 being only two-thirds of the London rate. 



10. Pumping is the only item of annual working expenses 

 mentioned in the essay. There is, however, much else to be 

 allowed for, such as — (1) wear and tear of machinery, (2) 

 repairs to sewers, traps, gratings, and works of all kinds, (3) 

 flushing the sewers and clearing out obstructions now and 

 then, and (4) removing the sludge from the gratings at the 

 filtration area, and digging it into the ground. The interest 

 oil a loan must also be provided, as well as a certain sum for 

 the repayment of the loan. Then there would be the 

 establishment required to enforce the rules that would have 

 to be adopted, and to superintend generally the working of 

 the scheme ; a certain office establishment would also be 

 necessary. A drainage scheme cannot be left to each local 

 authority to do what it pleases ; there must be one centred 

 authority over the whole ; this, indeed, the essay insists on. 

 As above remarked, the annual expenses of the drainage of 

 London amount to Is. a-head ; the drainage of Paris costs 

 still more. At Is. a-head, the annual cost in Melbourne for 



* " Proceedings of the Institution of Civil Engineers," vol. 49, p. 219. 

 f Ibid, vol. 53, pp. 193, 201. 



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