The Sun.
London, England, 1863-07-20 00:00:00

METROPOLITAN MAIN DRAINAGE.

On Saturday the first step was taken towards
utilising the now- gigantib— System of subterranean
tunnels which- constitute the works of the Main
Drainage, by lowering the `contents of the High-
level Sewer, which collects the drainage of Hamp-
stean, Highgate, and Holloway, Camden-town,
Hackney, and Bethnal-green, for the first time into
the river at Barking. This occasion was taken ad-
vantage of by a large party of members of both
houses, members of the Board of Works, engineers,
and scientific gentlemen, to pay a long visit of in-
spection, to the drainage works now in various stages
of progress on both sides of the river.
The whol3 party assembled early on Saturday in
tlte tea-room of the House of Commons, and among
the many persons of distinction present were the
Archbishop of York, the Duke of Grafton, the Duke
of Manchester, the Marquis of Westminster, the
Marquis of Salisbury, Lord Henniker, Lord Cal-
thorpe, Earl Pow is, Lord Harris, Lord Lifford, Lord
Ilanover, E irl Clanwilliam, Lord IVlanvers, Lord
Talbot de Malahide, Lord Wodehouse, the Earl
of Harrow by, the Earl of Yarborough, the Earl of
Shrewsbury, Lord Keane, Lurd Skelmersdaie, the
Chancellor of the Exchequer, the Right Hon. Mr.
Cowper, M.P., Sir J. Trollope, M.P., Lord Clarence
Paget, M.P., Lord Stanley, M.P., Mr. John Walter,
M.P., Mr. Kinnaird, M.P., Mr. A. Turner, M.P.,
the Lord Mayor, MT., Mr. A. Mills, M.P.,
Mundy, M.P., Sir Stafford Northcote, M.P., Mr.
R. M. O'Ferrall, M P., Lieutenant-Colonel Packe,
M.P., Mr. Paget, M.P., Mr, Papillon, M.P., Mr.
Peacocke, M.P., Hon. A. G. J, Ponsonby, M.P.,
Mr. Powell, M.P., Mr. Roebuck, M.P., Lieutenant-
Col, Rowley, M.P., Mr. W. F. Russell, M.P., Mr.
J. A. Smith, M.P., Mr. Stansfeld, M.P., Hon.
F. J. Tollemache, M.P., Hon. C. Trefusis, M.P.,
Mr. Warner, M.P., Mr. Western, M.P., Lieut.-Col.
White, M.P., Mr. Woods, M.P., Mr. P. P. Bou
verie, M.P., Mr. Adair, M.P., Mr. Alcock, M.P.,
Mr. Ayrton, M.P., Mr. Beale, M.P., Mr. Beecroft,
M.P., Mr. Bramaton, M.P., Sir B. Bridges, M.P.,
Mr. Briscoe, M.P., Sir H. H. Bruce, M.P., Mr.
Tite, M.P., Mr. T. Collins, M.P., Mr. Marsh, M,P.,
Col. Sykes, M.P., Mr. J. Wyld, M.P., Lord Fer-
mop, M.P., Mr. Forster, M.P., Mr. H. Foster,
M.P., Captain W. Gray, Mr. Greene, M.P., Mr. H.
Bruce, M.P., Mr. Gregory, M.P., Mr. Powell (Cam-
bridge), M.P., Mr. Collins, M.P., Mr. Hankey,
M.P., Mr. Taylor, M.P., Mr. Sullivan, M.P., Lord
A. Churchill, M.P., Mr. Doulton, M.P., Mr. Hume,
M.P., Hon. P. J. Locke King. M.P., Lieut.-Col. B.
Knox, M.P., Sir E. H. K. Lacon, M.P., Rev. E.
W. Andrews, Sir R, Mayne, Mr. Thwaites, chair-
man of the Metropolitan Board of Works, Mr. L.
Taylor, Mr. Terry, Mr. Bodkin, Mr. Nicholay, Mr.
Smee, Mr. Bazalgette, the chief engineer to the
Board of Works, &c.

As on the occasion of the somewhat similar visit
the members of both Houses paid to the works
this time twelve months, so in this also Mr.
Bazalgette before starting addressed some short
remarks to the party on the nature and purpose of
the works they were about to visit. He pointed
out briefly how, with the enormous increase of the
metropolis, the increased facilities for drainage into
the Thames had added to the mass of sewage daily
poured into it, till the evil was now become almost
unbearable. For 18 hours out of the 24 the outfalls
of most of the metropolitan sewers were tide•locked,
and :on days of heavy rain the waters from the
higher grounds flooded the basements and cellars
of low-lying districts with both water and
sewage. These low-lying districts could only be
properly drained by continuous pumping, and
though one important feature of the new system
was to reduce pumping to a minimum and carry off
the water by gravitation, still pumping was in some
places absolutely necessary. Another difficulty
which had to be met was the varying quantities of
sewage and 41 storm" water to be dealt with. Four
times as much sewage passed down the sewers at
midday as at midnight, the maximum flew being
about equal to a rainfall of a quarter of an inch in
24 hours, and the sewers were quite large enough
to carry off this rain together in with the maximum
quantity of sewage. But this qaantity was greatly
exceeded about 24 days in the year by heavy
storms, which added more than a hundred times to
the quantity the sewers could carry off at once ;
and as it would have been almost impossible to con-
struct sewers large enough to carry off these flood
waters, the existing main sewers were made to act
as storm overflows, so that when the intercepting
main sewers were full the surplus storm waters
should pass through the storm overflows into the
Thames ; and it was to these storm outfalls on the
north and south sides of the river, that the visit of
Saturday was paid.

The party embarked on a steamer at the Speaker's
Stairs, and proceeded down the river to Crossness
Point in Erith Marshes. While on the voyage down
we may venture on giving our readers the general
features of this great Main Drainage plan—a work
of such magnitude as no city in the world but this
would require, and certainly one of such cost as few
cities in the world but this could afford to pay for.
The subject of sewage is not a clean one, nor one
adapted for the literature of the dog days ; but after
inhaling dirt and drinking dirt for so many years
we may well efford to read about it, and to look
statistically into that foulest of all our great
sewers, the river Thames. Until the adoption of
the present scheme the object of all London drainage
was to make the Thames the great maie sewer of the
metropolis—an oe:
ject which we shall see was realised
to the fullest possible extent. A:1 the sewers in Lon-
don, on both sides of the river, run due north and
south, discharging themselves into the Thames
within a length of some five or six miles. At the
very first g!ance this arrangement seems bad enough,
though it is infinitely worse when we come to exa-
mine how it was arranged to work. On both sides
of the river the banks are very little above high-
w r mark, while the average level of the ground
immediately behind them is much below it; halt
Lambeth, Bermondsey, and Rotherhithe being 6ft.
below high-water level. Of course, when this is
the level of the ground the sewers are much lower
still, and their outlets so completely tide-locked that
it is only at dead ;ow
water that they can empty
themselves at all. Thus, for nearly 18 hours out of
the 24 the sewage 0
aboth sides of London used to
be, and is still to
jag
off
its
miasmaatint immense mmense extent, pent up, giv-
every street and house. As
we have said, it could
escape at dead low
water, when the only
returning tide immediately churned
it up the river, keeping
bridge
tilli the tide ebbed out,
its abominable " flotsam
finding 200,000 or 00,0lmg)0eangn.
manner
rons of filth to be ope-
rated upon in a similar
on
its r
was the arrangement 12 years ago, return. This
this was, it
entirely so still; bat, even badaeo'and is almost
was
o
houses
accordingly
capable of being made worse, and v
it was made. In 1849 most of the uses in Lon-
don had cesspools attached to theta,
large proportion were without any drainsla
d d a very
The alarming nature of this evil shows at all
itself
slowly but surely in the Bills of Mortality,e
the then Commissioners of Sewers, who were feebly
and
battling with the evils of the drainage System,
set to work to mitigate the cesspool dangereraby,
drainage, making the Thames, as usual, the general
receptacle. From that time to the present some
700 or 800 miles of new drains have been made,
and all cesspools made to drain at once into the
river. By this "improved" drainage some 200,000
additional gallons of sewage were daily added to
the Thames at low water, containing no less than
300 tons of " organic matter" which in this case is
the scientific term for filth. Nor was the Thames
the only sufferer, Wherever a stream could be
found, no matter how clear its waters or how bene-
ficial its course, drains were at once made into it.
Hackney Brook, once well-known to anglers as one
of the clearest and prettiest of streams that wound
from the north of London into the river Lea, was
made to vie with the Thames in filth and stench ;
and even the Serpentine was brought into requisi
tion, and the Ranelagh sewer (one of the largest in
London) daily discharged itself into that much-
prized piece of ornamental water. The Thames,
however, as the largest claimant, always got the
preference of dirt, and the great mass of corruption
which has flowed into it year after year has at :eat.
made it the largest and dirtiest open sewer in
Europe. The result, as a matter of course, has been
that in the summer months the stench from the

river has occasionally been intolerable. In 1857
great quantities of lime and chloride of lime were
put in daily ; in 1858 the same expedient to be
resorted to again ; and in 1859 the dose ad to be
increased to 110 tons of lime and 12 tons f chloride
of lime, costing some £1,500 per w Even in
a pecuniary point of view, however, is was not
the only evil of the system, The Thames in this
hot weather runs short of water, and when there
is no rain the collections of refuse in the sewers
have to be flushed into the river by arti-
ficial means. This flushing alone during
summer costs £20,000 a year to get the
poison into the Thames, where £20,000 more is
generally required to keep it from breeding a
plague. The tide in summer carries off little or
nothing. A marked object was set afloat in the
river and watched, with a view of ascertaining this
tact, and for three weeks it went backwards and for-
wards between Vauxhall and London bridges, with-
out going much further either way. During the
same period of course, the sewage of thea r
increased by its daily contribution, goes backwards
and forwards likewise under the summer Thames,
increased
lwaTaarendsd
yaeet
mpineoephliey. professmtaogilavitounddeer
anwdhyialipt
importanceso
s ot
thish
eevifitl have long
of theonnegbeenkn oßwena,radnedfNllvr.eßrkaez,aflegnegtthet,
the
nhisimfipgrhotvbeede,
al onndg,
eatnr de
nassiduously
yt to
uhhalvi
ee
o tphi en
i op nl a,
His main drainage scheme is
been successful.
nearly completed. In less than two years more
itwiltbee
effectually ed.
ntirelycompdierteeidh, the Thames purified,
and London
As may ba easily imagined, it is impossible in
an article like the present to give more than an
outline of this great plan, which may best be
briefly described as consisting of three gigantic
main tunnels or sewers on each side of the river.
'these completely divide underground London,
from west to east, and cutting all existing sewers at
right angles intercept their flow to the Thames, and
carry every gallon of London sewage under certain
conditions into the river on the north side below
Barking, and on the south to near Erith. These
main drains are called the High, Middle, and Low
Level sewers, according to the height of the localities
which each respectively drains. The High Level on
the north side is about eight miles in length, and
runs from Hampstead to Bow, being at its rise only
4ft. 6in. in diameter, and thence increasing in cir-
cumference, as the waters of the sewers it inter-
cepts require a wider course, to sft., 6ft., 7ft,, 10ft.
6in., lift. 6in., and at its termination, near Lea
river, to 13ft. 6in. in diameter. The drain is en-
tirely finished, and in full work. Its minimum fall
is 2ft. in the mile ; its maximum at the beginning
nearly 50ft. a mile. It is laid at a depth of from 20
to 26 feet below the ground, and drains an area of
14 square miles. The Middle Level, as being lower
in the valley on the slope of which London is built,
is laid at a greater depth, varying from 30 to 36
feet, and even more below the surfabe. This is
nearly complete, and extends from Kensal-green to
Bow. The Low Level will extend from Cremorne
to Abbey Mills, on the marshes near Stratford, but
as the city portion of this will pass through the
Thames Embankment we shall have occasion to
refer to it hereafter. At Bow the Low Level waters
will be raised by powerful engines at a pumping
station to the junction of the High and Middle
Level ducts, thence descending by their own gra-
vity through three tunnels to the main reservoir and
final outfall below Barking. These three tunnels
are each 9ft. 6in. in diameter and nearly four miles
long. Great engineering difficulties existed in the
construction of these main arteries, as, from the
height at which they all meet, it was necessary to
take them above the level of the manhes leading to
Barking. For a mile and a half the embankment
which encloses the three tunnels is carried on brick
arches, the piers going 18ft. below the surface, and
being based on solid concrete. In the marshes at
Barking the reservoir for the reception of the
sewage of the north side is formed. This reservoir
is a mile and a half long by 100 ft. wide and
21ft. deep. It is made of this great length
in proportion to width to allow of its being roofed
with brick arches, which are again covered with
earth, to a considerable thickness, so that not the
slightest smell or escape of miasma can take place.
This is eapable of containing more than three times
the amount of sewage which can enter it while the
pipes are shut, and thus, when all is complete, the
works will not only be large enough to take off all
London's sewage now, but its sewage when London
is double its present size.
While the sewage is in the reservoir we have
spoken of, it will be completely deodorised by an
admixture of lime. When the tide is at its height
the sluices which pass from the bottom of the reser-
voir far out into the bed of the river will be opened,
and the whole allowed to flow away. It takes two
hours thus to empty the reservoir, by which time
the tide will be flowing down strongly, and will
carry its very last gallon a distance of 13 miles below
Barking, which, being itself 13 miles below Lou-
don, will place the contents of the sewers, every 12
hours, 26 or more miles distant from the metropolis.
Thus, instead of letting loose the rankest of this
great city's abominations in the very midst of Lon-
don, and leaving it to stagnate, or, still worse, to be
agitated backwards and forwards in a small body of
water, it will all be carried away a distance of 13
miles, then deo& rised, then suffered to escape into
a body of water more than a hundred times greater
than that into which it now crawls, and thus disin-
fected and diluted, so as to be without either taste
or smell, swept still further down the stream, till
every trace of it is lost.

On the south side the three great sewer arteries
are constructed on similar plans—the High Level
from Dulwich to Deptford; the Middle from Cfap-
ham to Deptford ; and the Low Level from Putney
to Deptford. At this point is a
lo pumpingto t station,h e
h lgh
which raises the water from the
wtunnel
to whence it flows away througha
to Crossness Point. One part of this tunnel, pass.
ing under Woolwich, is a mile and a half
in loft,
length,
without a single break, and driven at a depth
o
feet from the surface. At the outfall will be anothertoB
pumping station, to lift the water to the reservoir.
The southern reservoir is only five acres in extent
that on the north it-t. 14. In the reservoir it will be'
deodorised and discharged in a similar way to that
we have already described.
It was over these last-named works, amid an ap-
parently inextricable labyrinth of culverts, arcades,
chambers, and columns, that the visitors were con-
ducted yesterday, first inspecting the channel for the
overflow of storm water, next the two culverts, as
large aimost as railway tunnels, wnich carry the
sewage to the east and west pumping stations. Be-
fore the entrance to the pumps are massive iron
strainers, which keep out all the coarse refuse
brought down the sewer, and which afterwards
dredged up by the filth hoist into the filth chamber,
which is flushed into the river at low water. The
pumping-house is nearly finished and the iron work
of the engines begun. The pumping stations will
each consist of an engine-house, containing 10
boilers calculated to work up to 500 horse power
f 7
nominal. This power working through eight pumps
n
feet diameter and 4 feet stroke will daily raise
19,000,000 cubic feet of sewage from 19 feet below
low water to the level of the outfall; but, in case of
necessity, the pumps can raise 25,000,000 cubic feet
per day. The reservoirb into which it will all flow
is not yet finished,
will holdt2hoe,soeowo,:sugt on when roofed in with brick
s gallons of sewage. After in-
spectingaturday the visitors were
taken across the river t
othe Barking outfall, where
works are
thelarger,northsewage
simpler, and much more ad-
tvha e n
ee
d,
for on is brought at such
a level as to discharge into theher reeservoir by ins own
gravitation. The reservoir
is far advanced,
sew er
a great deal of it being roofed in,
that all
will be completed in a few months
more. Close
rir.
to this the contents of the High
Level
theywere
will
turned
iu onfu
future
eo
flow,the river
through
Nd iiraegcattr,hae
od
eservof not as
The inspection of this murky
as it cams tumbling down seemed to sewage
ewge
not
at all unpleasant to members who are aaccus-
tomed to legislate in hot weaihe on the banks of the
largest sewer in the world—the Thames. After
gazing on this unsavoury volume of dirt for some
time, by way of an appetizer, the whole party re-
turned to the great reservoir to lunch. At this re-
past various loyal and congratulatory toasts were

given—that of Mr. Thwaites, the chairman of the
Board of Works, and Mr. Bazslgette, his chief
enginzer, being greeted with much enthusiasm.
In the afternoon tbevisitors returned to town, bay-
ing enjoyed an agreeable, and, we, may add, an in-
structive excursion.

he total length of the three rows of intercepting
sewers, the course of which we have sketched on
each side of the river, will be 50 miles, and before
all the works are completed 800,000 cubic yards of
concrete will be consumed, upwards of 300,000,000
of bricks, and 4,000,000 cubic yards of earthwork.