152 MR. J. P. JOULE ON THE UTILIZATION OF THE 
6th. The proposed system must be considered a filthy 
one, as instead of removing sewage to the soil, which is 
the natural deodorizer, it will cause its accumulation in the 
bed of the river at a distance of only a few miles from the 
city. Even the liquid portion will remain for months near 
the spot where it is introduced, as is proved by the experi- 
ments of Mr. Forster, who found that a float put into the 
river at Barking advances only five miles in its course to- 
wards the sea in an entire fortnight.* 
The above are some of my reasons for believing that 
the proposed plan of the Board of Works will fail in pro- 
moting the object to attain which the promoters have 
sacrificed what ought to have been their first considera- 
tion. I enter not now on various points, such as the des- 
truction of fish in the river and in the wells of ships, and 
consequent interference with a useful trade; the formation 
of banks apprehended by some, and the consequent im- 
pediment to navigation; the expense; and other details 
which must be of minor importance in a question ulti- 
mately involving the life and subsistence of an entire 
population. 
The government Referees remark that the pollution of 
streams by sewage throughout the country is an evil which 
is increasing with improved house-drainage,t and they 
sought to place the outfalls as low as Sea Reach. The 
present is a plan which supplements and perpetuates the 
* Report of Government Referees, p. 172. Walter Crum Esq., F.R.S., 
has suggested to me as very possible that there may be times when greater 
quantity of water enters the Thames by flood than goes out by ebb-tide, 
owing to the large quantity of water taken from the river by evapora- 
tion in dry and hot weather.— See Dalton on Rain, Evaporation, &c., 
Manch. Memoirs, vol. v. p. 346. 
+ The pollution of springs is a still more serious evil, in many instances 
involving the necessity of conveying the rain which falls on the moors 
through a long series of pipes. It is to be doubted whether such water 
is as good for drinking purposes as uncontaminated spring water. 
