This branch of the subject hardly forms part of my present inquiry,
but, having pointed out the defects of the sewers, it seems but
reasonable and right to say a few words on the measures determined
upon for their improvement. It is only necessary for me, however, to
indicate the principal characteristics of the new, or rather intended,
mode of sewerage, as the work may be said to have been but commenced,
or hardly commenced in earnest, the Report of Mr. Frank Forster (the
engineer) bearing the date of Jan. 30, 1851.
In the carrying out of the engineer’s plan--which from its magnitude,
and, in all human probability, from its cost, when completed, would
be _national_ in other countries, but is here only _metropolitan_--in
the carrying out of this scheme, I say, two remarkable changes will be
found. The one is the employment of the power of steam in sewerage; the
other is the diversion of the sewage from the current of the Thames.
The ultimate uses of this sewage, agriculturally or otherwise, form no
part of the present consideration.
I should, however, first enumerate the general principles on which
the best authorities have agreed that the London sewers should be
constructed so as to ensure a proper disposal of the sewage, for these
principles are said to be at the basis of Mr. Forster’s plan.
I condense under the following heads the substance of a mass of
Reports, Committee Meetings, Suggestions, Plans, &c.:--
1. The channels, or pipeage, or other means of conveying away
house-refuse, should be so made that the removal will be _immediate_,
more especially of any refuse or filth capable of suspension in water,
since its immediate carrying off, it is said, would leave no time for
the generation of miasma.
2. Means should be provided for such disposal of sewage as would
prevent its tainting any stream, well, or pool, or, by its stagnation
or obstruction, in any way poisoning the atmosphere. And, as a natural
and legitimate result, it should be _so collected that it could be
applied to the cultivation of the land_ at the most economical rate.
3. In the providing works of deposit or storage in low districts, or
“of discharge where the natural outlets are free,” such works should
be provided as would not subject any place, or any man’s property, to
the risk of inundation, or any other evil consequence; while in the
construction of the drainage of the substratum, the works should be
at such a depth below the foundation of all buildings that tenements
should not be exposed to that continued damage from exhalation and
dampness which leads to the dry rot in timber, and to an immature decay
of materials and a general unhealthiness.
There are other points insisted upon in many Reports to which I need
but allude, such as
(_a._) The channels containing sewage should be of enduring and
impermeable material, so as to prevent all soakage.
(_b._) There should be throughout the channels of the subterranean
metropolis a fall or inclination which would suffice to prevent the
accumulation of any sewage deposit, with its deleterious influence and
ultimate costliness.
(_c._) Similar provisions should be used were it but to prevent
the creation of the noxious gases which now permeate many houses
(especially in the quarters inhabited by the poor) and escape into
many streets, courts, and alleys, for until improvements are effected
the pent-up sewage and the saturated brickwork of the sewers and older
drains must generate such gases.
(_d._) No tidal stream should ever receive a flow of sewage, because
then the cause of evil is never absent, for the filth comes back
with the tide; and as the Thames water constitutes the grand fount
of metropolitan consumption, the water companies, with very trifling
exceptions, give us back much of our own excrement, mixed with every
conceivable, and sometimes noxious, nastiness, with which we may brew,
cook, and wash--and drink, if we can. Filtering remedies but a portion
of the evil.
Now it would appear that not one of these requirements, the necessity
of which is unquestioned and unquestionable, is fully carried out by
the present system of sewerage, and hence the need of some new plan in
which the defects may be remedied, and the proper principles carried
out.