The Sun.
London, England, 1865-04-04 00:00:00

The Main Drainage of the Metropolis.

To-day his Royal Highness the Prince of Wales
will celebrate what may be fairly termed the com-
pletion of the Main Drainage of the metropolis by
an inspection of the works which have been long
finished and in operation and by starting the great
engines at Crossness Point, which thenceforth will
daily pump the 24,000,000 gallons of sewage and
rainfall on the south side of the water into the
Thames at Erith. Seldom in any country has a
more important, more extensive, more costly, or
more difficult work than this been executed, and
certainly never in any of the cities of England.
London, even with all its faults of a poisoned
Thames, was still in the abstract and, as far as the
mere construction of sewers went, always the best
drained city in the world. After to-day it will hold
a position in this respect which will be above com-
parison with any other European capital. For such
an all-important boon it is mere justice to say that
we are almost entirely indebted to the Board of
Works, who have gone about their duties in an
earnest, practical way, which sets a high example
alike to both the Government and the City Corpo-
ration. With the assistance of their engineer, Mr.
Bazalgette, they have triumphed over natural and
artificial obstacles in the way of the perfect drain-
age of this great province of houses, and whether it
has been in making new streets or in widening nar-
row ones, whether in embanking the Thames, or
giving new designs for lamp-posts, nothing in the
way of metropolitan improvements has as yet proved
either above their capacity or beneath their atten-
tion. The work which will be inaugurated to-day
has been more important and difficult in its execu-
tion, and will be infinitely more beneficial in its re-
sults, even than the embankment of the Thames it-
self. If ever the history of our main drainage works
is written we venture to think that the story of its
engineering difficulties will vie with all that may
be found in the " Lives of the Engineers," while it
is certain that even in that history of mechanical
and engineering marvels there will be no record
found of works so dangerously difficult effected at
so small a cost. What they have been may be best
understood by a few figures. There are now about
1,300 miles of sewers in London, and 82 miles of
main intercepting sewers.: Three hundred and
eighteen millions of bricks and 880,000 cubic yards
of concrete have been consumed, and three and a
half million cubic yards of earth have been exca-
vated in the execution of these main drainage works.
The total pumping power employed is 2,380 nominal
horse-power ; and if at full work night and day
44,000 tons of coal per annum would be consumed.
The sewage on the north side of the Thames at pre-
sent amounts to 10,000,000 cubic feet a day, and on
the south side to 4,000,000 cubic
,feet per day ; but
provision is made for an anticipated increase up to
11,E millions on the north side, and 54 millions on
the south side, in addition to 284 million cubic feet
of rainfall per diem on the north side, and 171 mil-
lion cubic feet per diem on the south side, or a total
of 63 million cubic feet per diem, which is equal to
a lake of 482 acres, 3 feet deep, or fifteen times as
large as the Serpentine in Hyde-park.
The cost of these stupendous works has only
amounted to little more than £4,000,000. The sum
for defraying this expense is raised by loan, and paid
off by a 3d. rate levied on the metropolis, which pro-
duces £180,262 per annum, the rateable value being
£14,421,011, and the principal and the interest of
the loan will be paid off in 40 years. As the works
have advanced constant and full notices of their pro-
gress have appeared in these columns. From these
notices, and from a most able paper which has just
been read by Mr. Bazalgette
at the Institute of Civil
Engineers, a brief resume can now be given of all
that up to this day has been accomplished.
The old system of drainage was simply to make
the Thames the great main sewea of London. All
drains and sewers flowed north and south into the
river, where their low level prevented their dis-
charging at any time but dead low water, when all
London's refuse was kept churning backwards and
forwards, till the river became one of the foulest
and most offensive open sewers in Europe. As the
tide rose it closed the outlets, and poured back the
sewage flowing. from the high grounds which accu-
mulated in the low-lying portions of the sewers,
where it remained stagnant in many cases for 18 out
of every 24 hours.w During
that period the heavier
ingredients
were deposited,
and from day to day
accumulated in the sewers; besides which, in times
of heavy and long continued rains, and more parti-
cularly when these occurred at the time of high
water in the river, the closed sewers were unable to
store the increased volume of sewage, which then
I rose through the house drains and flooded the base-
mentsl of the houses.

The effect upon the Thames of thus discharging
the sewage into it at a time of low water was most
was it carried by the
only
rising buepcathuseerinvoetr, otnloe brought back to Lon-
don by the following ebb tide, there to mix with
each day's fresh supply—the progress of many days'
accumulation towards the sea being almost imper-
ceptible—but the volume of the pure water in the
river being at that time at its minimum rendered it
and disinfecting such
qvuiastteminacssaepsabolfeseowfagdile.uting

This, however, was not the worst. The pent-up
refuse, as it gradually deposited in the sewers, en-
tailed an annual expense of some £30,000 to flush
the filth into the river, and thus again entailed a still
further outlay of some £9OO a week in summer months
for disinfectants to prevent the stench from the
stream which has been so successfully poisoned from
breeding a plague. The innumerable commissions of
sewers which were issued quite failed to abate this
monstrous evil, and it was not till the appointment of
thepresent Board of Works that the matter was ener-
getically taken in hand, and has now been carried out
under their ere, and according to the ?lam of their