The Sun.
London, England, 1861-10-09 00:00:00

THE LONDON SEWERAGE.

It is -not often that we can accuse London vestries
of hiding their light under a bushel. Theh mem-
bers are generally considered to be noisy and vulgar,
with narrow views and a vast amount of self-asser-
tion. What little they do they parade before the
world, and are never so happy as when their ac-
tions, quarrels, and discussions are fully reported in
their parochial organs. Of these latter newspapers
the metropolis can now she/. between 20 and 30,
from the City Press to the IMgsland Advertiser.
The Metropolitan Board of Works, which we
shall not insult, we hope, when we call it a sifted
upper parish parliament, has been singularly free
from this desire for publicity. It has now been in
existence for nearly six years, and yet during that
time it has never courted the attention of the Lon-
don press. It has carried on its weekly debates in
the council chamber of Guildhall, and its business
arrangements in an old house in Soho-square, while
something very like a palace has been preparing
for its reception in Spring-gardens. It has cut a
few new thoroughfares, altered the names of a few
streets for better or worse, issued its reports
from time to time, collected its special rates and
spent them, talked a good deal, as all repre-
sentative assemblies will do, and that is all. Those
journals which thought proper to report its debates
were welcome to its benches; but its great work—
the Metropolitan Main Drainage Scheme--which is
to immortalise a much respected engineer, and
crown with everlasting laurels some 46 picked ves-
trymen, was largely kept in.lthe background. For
some years it has been the =atom of the board to
makeofof London,
those vast under-
ground sewer-works
o rk s inspectionth the
outskirts
which most ratepayers hear of through the tax-
collector, but seldom see or understand. At what
r nd an
s e anneal
we r -
period these mysterious official visits were made to
the unsavoury regions of sewage, few people,
except cabmen and hotel-keepers were aware.
The work was a mystery, and the inspection was
made a mystery also. Some restless ratepayers
goaded on excitable vestrymen to declare in open
vestry that the unruly offspring of Lord Llanover
was a pernicious sham, and that there were no new
sewers being constructed anywhere except in the
imagination of a few deluding draughtsmen.
Whether the recent contest between Mr.
Thwaites and the Right Hon. W. Cowper for the
management of the proposed Thames Embankment
has put the Metropolitan Board of Works upon its
mettle ; or whether some discreet' friend has whis-
pered in the ears of the Sewer Lords that further
secrecy would be indecent and impolitic, it is im-
possible to say, but the annual inspection of the
great main drainage works yesterday was attended
by so many running historians in the shape of
"special correspondents," that the public will no
longer be uninformed on a deeply interesting sub

If the history of the London sewerage system
was elaborately written, it would be necessary to
quote Magna Charta and the laws of Romney
Marsh. It dates back some five centuries, and
deals with a legislation whose aim was to preserve
the existing watercourses from any obstruction. As
houses became built over the metropolitan area, and
population increased, these watercourses, notwith-
standing the severe prohibitions against using them
as receptacles for sewage, became robbed of their
virgin purity. When they notoriously ceased to
flow as limpid streams and purling brooks, they
were slowly and unwillingly covered over by the
local authorities. From this moment they became
sewers in every sense of the term, although it was
not until the beginning of the present century that
any miscellaneous discharge into them was made
legal. All tile acts were very defective for house
drainage ; and most of the local acts enforced the
construction of cesspools. About 1810 there must

have been two thousand cesspools in London, and
their increase was only checked by mechanical im-

provements in connection with an enlarged water
supply.

The old downward, or Thames seeking main
sewers of London, at the present time, are about
170 miles long; and they run into the river at
various points, through about 180 outlets on the
north and south side. The district and private
sewers which join these main channels must be
1,600 miles long within the metropolitan boundary;
and the drain-pipes—those smaller veins which
again join the district arteries—must be 4,000 miles
long within the same limits. The district sewers,
as their title implies, are, governed by district
boards, or committees elected by the various parish
vestries ; while the main sewers are formally handed
over, in trust, to the Metropolitan Board of Works.
Some sewer engineers quarrel about the proper
definition of a main sewer, and hold that the
channel is only properly so called when it follows
the line of an ancient watercourse. In this case
London would have few main sewers except the
Fleet, the London-bridge sewer, which has usurped
the channel of the old Walbrook, and the King's
Scholars' Pond sewer, which is all that is left of
that ancient bourne or rivulet that meandered
pleasantly frorn Hampstead through Mayfair into
the Thames, and gave us the corrupted name of
Marylebi,ne, or the brook of St. Mary. We may add
the great Ranelagh sewer to this list, which repre-
sents the Westbourne and the Effra, on the Surrey
side, and we shall then have nearly all the main
sewers based upon old natural channels. The artifi-
cial main sewers which swell the trust property of
the Metropolitan Board of Works are only main
sewers by Act of Parliament.

All these great downward channels may be de-
scribed roughly as funnel-shaped—the narrow end
being at the source in the hills, the broad end being
in the valley where it discharges into the river.
The velocity of their currents I varies from one to
three miles an hour. The most important of them
discharge, at certain periods of the day, in dry
weather, from 1,000 to 2,000 enbic feet of sewage per
minute, the greatest height being generally main-
tained during the hours between nine in the morn-

ing and five in the afternoon. At other periods of
the day the same sewers rarely discharge more than
one-fourth of this quantity. The sizes of these under-

ground tunnels at different points of their course are

constructed so that they may convey the waters
safianordwy icnwognasstethaeruooeufngtthu
bntunhreeslmtl
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very defective condition, especially at the roof and
the base ; and some of them are still black un•
covered ditches. Mr. Bazalgette, the chief engineer
of the Metropolitan Board of Works, in a recent
report, estimates the cost of repairing these tribu-
tary sewers at half-a-million sterling.
A London population of nearly 3,000,000 daily
defiling the Thames through these more or less de-
fective tributary sewers, is the real creator of this
great main drainage scheme. The plan is chiefly
one of interception—that is to say, the new sewers '
will stretch like a girdle round London, cutting
through these various downwatil sewers, at different
levels on the north and south side of the river, and
carrying the sewage into tho Thames at a point be-
tween Barking and Plumstead. The plan has had
Many opponents, and Las rawly but no scheme

has been more thoroughly investigated by scientific
authorities. It was mapped out by the late Mr
Foster and Mr. Haywood, in 1849 ; Messrs.
gette and Haywood modified, extended, a
tinned it, upon paper, in 1854 ; the Metrop
Board of Works, when it commenced its career on
Jan. 1, 1856, took it into consideration ; Mr. Baz
gette remodelled the plan in the same year; a Cfr
vernment commission, consisting of Messrs. Gallon,
Simpson, and Blackwell, reported for and against
the plan in 1857 ; Messrs. Bazalgette, Hawksley,
and Bidder again reported for and against the Go-
vernment report ; and, finally, Mr. Bazalgette, as
chief engineer to the sewer parliament, began to
carry out his thrice remodelled project in 1858.
The works which the board and their friends in.
spected yesterday, and which some 1,500 vestrymen
propose to inspect to day, were chiefly the two great
outfall channels, north and south—one in the Bark-
ing marshes, and the other in the Erith marshes,
14 miles below London-bridge. It would take a
month to go carefully over all these new sewer
works, and therefore a brief description of them,
drawn from former observation, may be useful to
explain the relation which the part seen bears to the
part not seen.
On the north side of the Thames there are three
main tunnels—the high level, just completed; the
middle level, not long begun by Messrs. Brassey
and Co. (the progress of which, in the part along
Oxford-street, will be checked next year, out of re-
gard to the Exhibition traffic) ; and the low level,
only planned out, much of which it is intended to
carry through the proposed Thames embankment.
On the south side of the Thames there are two
main tunnels—the high level, with an important
fork, called the Effra branch ; and the low level,
not yet begun. These five main tunnels, with their
branches on both sides of the river, some of which
will help to drain the districts they pass through,
will be at least 71 miles long, and will cost, with
sewage .filtering reservoirs, pumping stations,
engines,'&c., at least three millions sterling. About
five-and-twenty miles of these tunnels:are now com-
pleted, and the contractors are going on rapidly
with the lengths left to be constructed.
The high level sewer, just completed on the north
side of the Thames, begins at Hampstead with a
tunnel 4 feet in diameter, and extends, increasing
here and there in size, until it reaches something
like a diameter of 93 by 12 feet at the point were it
joins the river Lea at Old Ford. Its course is from
Highgate, down the Holloway-road, under the
Great Northern Railway and New River ,1., to
Stoke Newington, and then through Hackney and
the Victoria-park to its aqueduct across the river
Lea. It has just been completed, forming a round-
about tunnel nine miles long, and swallowing up in
its course the open part of the Old Hackney Brook.
Half a million of cubic yards of earth have been
dug out to form its channel ; it has sucked up 40
million of bricks, 200,000 bushels of Portland ce-
ment, 350,000 bushels of lime, 100,000 cubic yards
of concrete, 17 tons of hoop iron, and has employed
1,500 men from week to week.
The great middle level sewer has been begun by
the contractors at both ends—namely, at Old Ford
and at Bayswater. It will have three branches,
called the Piccadilly, Dover-street, and Coppice-row
branches. The main line begins in an egg-shaped
tunnel, about 4 feet in height, and is to increase in
size, hero and there, until it ends in a circular tun-
nel 102 feet in diameter. Its course will be from
Paddington to Notting-hill, along Oxford-street,
through Bloomsbury and Clerkenwell, along Old-
street, across Shorediteh. through Bethnal-green,
and under the Regent's Canal to Old Ford, where
it runs for some distance side by side with the high
level sewer. The contractors estimate that about
half a million cubic yards of earth will have to be
dug out for this channel, and that it will suck up
about 55,000 cubic yards of concrete, and 40 mil-
lion of bricks. The number of workpeople em-
ployed in it will be at least 1,000. Both of these
sewers are wide enough at their junction-end,
where they run for some distance under a raised
clay and concrete embankment, to admit a horse
and cart, and you could ride up them on horseback
for miles. Here it is that several great " overflow
chambers" are built, where the storm waters, when
they reach a certain height, can flow down into the
river Lea below, and thence into the Thames above
Blackwall.

The northern outfall sewer, which, when com-
pleted, is to convey the combined streams of the
high and middle level channels, and the stream of
sewage to be pumped into it from the low level
sewer, stretches across tho marshes to Barking-
creek. It will be about five miles long, and it is
that portion of the work which was most closely
examined yesterday. For one mile it will consist
of two lines of tunnel enclosed in a raised embank-
ment ; and for the remaining distance of four miles,
of three lines of tunnel, each nine feet in diameter.

It will cross over seven streams, including the river
Lea; it will pass under the Eastern Counties Rail-
way, and over the North Woolwich and Tilbury and
Southend lines in aqueducts. It is estimated that
1,121,000 cubic yards of peat and soft ground will
have to be cut out and piled up to form the embank-
ment ; that 629,000 cubic yards of concrete will be
required for the same purpose ; that the tunnels
will suckup about 27,000 rods of reduced brickwork,
120,000,000 of bricks, 1,650,000 bushels of cement,
3,834,000 bushels of lime, and 4,000 tons of wrought
and cast iron for the bridges over the streams and
railways. A concrete foundation is being laid down
for the brickwork to be built upon, much in the
style in which the old Roman roads were most pro-
bably made ; and, where the marshes are very soppy
brick piers are being constructed to support the
tunnels and embankment.

This great outfall sewer will carry all the London
sewage gathered from the north side of the Thames
into a covered reservoir capable of containing seven
millions of cubic feet of sewage, and corresponding
with a covered reservoir on the Plumstead side for

the southern sewage, capable of containing four
millions of cubic feet. Both these reservoirs will
be raised some 21ft. above the level of the outfall
sewers, and the streams will be pumped into them.
The final discharge of the fluid sewage at high-
water—the solid sewage being deposited in the
reservoirs—will take place through covered chan-
nels buried under water, and communicating with
the centre and bottom of the river.
r.:2. The southern high-level tunnel begins at Clap-
ham-common, and winds its way through Stockwell
and Camberwell to Peckham, where it is joined by
the Effra branch, which comes down from Dulwich.
The two tunnels continue from Peckham, through
New-cross until they end in Deptford-creek, where
they are provided with storm overflow-chambers.
The whole length of this high level sewer is be-
tween nine and ten miles, and about two-thirds, at
different points of its course, is completed. It
begins, like most of the others, as a circular tunnel,
about 4 feet in diameter, and increases in size here
and there, until it ends in a diameter of at least
10:1 feet. -When finished it will cut off and divert
the upland waters which now flood those low and
tide-locked districts on the south side, which are
far below the level of the river. It is estimated that
this intercepting sewer will suck up 82,000 cubic
yards of brickwork, 30,000,000 of bricks, 200,000
bushels of cement, 400,000 bushels of lime, 75,000
cubic yards of concrete, and will require more than
.100,000 cubic yards of ground to be cut our, and
nearly the same quantity of earth and materials to
be carted.

The southern low level intercepting sower, like
its brother on the north side, is at present only
mapped out on paper. Its course will be from Put-
ney through Battersea, Brixton, Camberwell, the
Old Kent-road, and across the market-gardens to
Deptford. It will be provided with a couple of
storm overflow branches running into the Thames
at Vauxhall and Deptford, and a north or Ber-
mondsey branch, which will gather up all the old
sewers running throug.4 that di sict, T 1.143 end "

the low level sewer will be at least 201 t. below the
itend of the high level sewer, and pumping power of
00 horses will be required, as on the north side,
o raise the stream into the great outfall tunnel.
The great southern outfall tunnel is now about
two-thirds completed. The length of this sewer-
channel will be about seven miles and a half, and its
diameter about 1.1211.

Its depth from the surface in many parts is very
great, especially about Woolwich ; and much of it
has been constructed, mole-like, underground,
without many of the inhabitants being aware of
its existence. Its course is from the Deptford
pumping station, through Greenwich and Wool-
wich, under the Erith marshes, to the covered
reservoir. It is estimated that about 500,000 cubic
yards of ground will have to be dug out for this
channel, and that about the same quantity of earth
and materials will have to be carted. It will suck up
100,000 cubic yards of brickwork, 37,000,000 of
bricks, and 600,000 bushels of cement. These works,
from their commencement, have given weekly em-
pioyment to upwards of 2,000 men. The inclination
of both the outfalls—north and south—is only two
feet in a mile.

The greatest sight, concentrated in one spot, for
touch-and-go. spectators and stout members of the
board intent upon getting over thereund, and not
very learned in engineering workii,i, the pomp gig
station works at Deptford. Here are 02 acres of
ground dug into pits 30 feet deep, filled with every
variety of shoring timber in every variety of posi-
tion; coffer dams being constructed in the middle
of the creek, divers working 40 feet under water,
engineers and engines toiling above, piles being
driven in, iron sewer pipes three or four feet in
diameter, stacks of bricks, cart loads of clay and
mud, and hundreds of men too busy to look even at
official visitors. This was the spot where the day's
excursion in tramway trucks and steam tugs came
to a triumphant close, and where a few of the mem-
bers, intent upon showing their zeal, asked ques-
tions that puzzled all the engineers to answer.
These memberd were doubtless very well meaning
men, but evidently not too much informed upon the
works being carried on in their name with their
corporate zeal and sanction. Like all members of
corporations they must be largely in the hands of
their practical officers; and while they possess such
hard working and conscientious engineers as Messrs.
Bazalgette, Grant, Cooper, and Lovick, and such
contractors as Messrs. Brassey, Webster, and Aird,
the ratepayers may know that the public money is
being carefully expended.