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208
THE METROPOLITAN SEWAGE QUESTION.
In my Annual Reports for 1885 and 1886, I referred,
under the heading "Metropolitan Main Drainage," to the
steps taken by the late Metropolitan Board of Works to
clarify and deodorize the sewage of the metropolis before its
discharge into the river; well-founded complaints having
been made with regard to the condition of the river, resulting
from the introduction of enormous volumes of crude sewage.
I mentioned also that the Board, in order to prevent nuisance
within the metropolis arising from the discharge of offensive
gases from the sewer ventilators, were adding disinfectants
at numerous stations to the sewage as it flowed through the
main sewers. It was hoped that this plan would ensure the
arrival of the sewage at the outfalls in a deodorized condition,
and thus assist in the production of a satisfactory effluent; the
object of the Board being to avoid the necessity for costly
land filtration of the effluent, as recommended by the Royal
Commission on Metropolitan Sewage Discharge, with a view
to ensure the removal of all odour and the possibility of
"secondary fermentation." The Board, in giving effect to
the views of their scientific advisers, incurred a large expenditure
for works of construction (which were not completed
until June, 1892), and in carrying out of the system adopted,
which involves the transport of the sludge, resulting from
precipitation, in specially constructed vessels, out to sea.
SIR HENRY ROSCOE'S REPORTS.
Deferring to the objections made to lhe system above described,
the Board, in 1887, retained the services of Sir Henry Roscoe, F.R.S.,
as consulting chemist and scientific adviser, to report on the question
of the deodorization of the sewage at the outfalls, and they ultimately
consented to the request of certain Sanitary Authorities—your
Vestry among the number—to make that gentleman's reports public.
The reports were five in number. The first, dated 16th May, 1887,
dealt with "The Dkodokization of Sf.wage in the Metropolitan