144 TRANSACTIONS OF THE CANADIAN INSTITUTE. [VoL. II. 



but the statistics Mr. Crimp has been able to gather do not show that it 

 is possible to obtain much profit from it. He says the manurial value 

 of sludge is now admitted to be very low, and except in a few isolated 

 instances sludge is recognized as a material to be got rid of in the 

 cheapest manner. Furthermore, if it possesses a commercial value, 

 commercial men may be safely relied on to utilize it. They can have 

 the sludge for nothing, in any quantity. Let them take it and deal with 

 it as they will. 



Just here let me interject a somewhat novel proposition made with 

 regard to the disposal of the London sewage, viz., by steamsJiip carriage. 

 It is intended to convey to sea, in specially designed steamships, the 

 sludge produced from the London sewage. The great advantage of the 

 method is that the sludge will never be seen. Precipitated in covered 

 reservoirs, transmitted from these precipitating tanks to special settling 

 tanks, from thence pumped into the sludge vessel and discharged far 

 from land, the sludge will disappear in the most speedy, cleanly and 

 safe manner that can be devised. 



The objections to this system are threefold, i. Waste of valuable 

 manure. 2. Possibility of nuisance on the coast. 3. Delay in transit 

 by fogs and stress of weather. The first objection has already been 

 answered, commercial men would take care of it, etc. The second 

 objection as to the possibility of nuisance on the coast is a mistaken one. 

 Examine the point closelv^ Some 3,000 tons of settled sludge, equal to 

 about 150 tons of organic matter, will be discharged per diem, under 

 water several miles from the coast. This will not be discharged at one 

 spot, but be spread over some thirty miles. Assume that the discharge 

 from one vessel holding 1,000 tons, equal to 50 tons of organic matter 

 formed a track when diffused in the water four yards deep by four yards 

 wide, and ten miles in length ; what would be the quantity of organic 

 matter in that polluted line of water? Only 16 grains in each gallon. 

 Given a gallon of water containing 16 grains of organic matter situated 

 say, ten miles from the shore, and in a strong tidal way, how much 

 offence will be given, after diffusion, oxidation, the feeding of fish, &c., 

 have acted their part by the time it has reached the coast, if it ever does 

 reach it? I think the objection is satisfactorily answered. 



The third objection, delay by fogs and stress of weather is a trivial 

 one. An increase in the capacity of the sludge settling tanks with 

 reserved steam power, which must be provided in any case to guard 

 against breakdowns, will effectually overcome this difficulty. If the 

 whole of the enormous naval traffic of England can be carried on as it 

 is, with almost mathematical precision, surely the carriage of a few 



