Sewage Disposal and Rivers Pollution. 347 
rink of it ; the next morning, although a hard frost had prevailed 
meantime, the sewage had all disappeared into the land.” The 
objection to filtration areas that they must necessarily be un- 
remunerative, since they are dosed with far too much sewage to 
allow of growing profitable crops, has become less serious since the 
idea of making a profit out of the application of sewage to land is 
in many places an impossible one and is now everywhere recognised 
as secondary to that of securing efficient purification. Moreover, 
as we see, the small acreage devoted to filtration on a properly 
planned sewage farm is an actual advantage to the farming. It is 
true that near most towns it is impossible to get sufficient land at 
an ordinary agricultural price to pemiit of the profitable application 
of sewage, but for all that there are situations and circumstances 
where sewage utilisation is not the dream of a bygone generation, 
as it is now the fashion generally to term it. The instance of 
Dantzig, already given, when sufficient waste land at a waste price 
was obtainable, is a case in point ; but a more instructive one is that 
of the Berlin sewage farms as described by Mr. Roechling ( loc . cit.). 
Here we have the sewage of a metropolitan population, not too 
favourably situated for the purpose, treated with success from a 
sanitary and even from a financial point of view, by the intelligent 
and thoroughly organised distribution over a sufficient acreage of 
land, comprised in several farms, under a combined system of irri- 
gation and intermittent filtration. The following abstract descrip- 
tion of these farms given by Mr. Roechling in the course of the 
discussion may be quoted in extenso : — 
The city of Berlin had now a population of If million, and was situ- 
ated in the sandy plains of North Germany, on either side of the Spree. 
The flow of the river was sluggish and it was held up by one or two locks; 
The Spree did not carry more water, in periods of great drought, than about 
450 cubic feet per second. It was at first intended to collect the sewage of 
Berlin at one pumping-station, and to treat it there chemically ; but this 
plan had been given up, and the sewage of Berlin was now pumped from 
twelve different pumping-stations within the boundaries of the town on to 
farms north and south of Berlin, from 6 to 12 miles distant from the heart 
of the city. The total area of the farms stood, on March 31, 1890, at 18,790 
acres, of which 11,016 were under sewage treatment, the rest being farmed 
agriculturally until it was required for the sewage of the town. The total 
daily flow of sewage amounted now to over 30 million gallons. 
The subsoil of the farms was chiefly sand, with a preponderance of 
loamy sand and sandy loam in places, especially on the northern farms. The 
effluent from the farms went into small ditches, which emptied into small 
streams, not bigger in places than from 10 to 12 feet across. The effluent 
from the northern farm came back to Berlin, whereas the effluents from the 
southern farms discharged into the Havel at Potsdam, several miles below 
Berlin. When the nature of the streams that took the effluent was con- 
sidered, viz., their sluggish flow, their small area in cross section (almost too 
small in places to carry both the sewage and the ordinary discharge), and 
their much-obstructed and very tortuous course, it would be admitted that 
the Berlin sewage farms were placed at a great disadvantage in this respect, 
and that there was every chance that an effluent not perfectly purified would 
set up secondary decomposition. 
