The Sun.
London, England, 1856-05-24 00:00:00

CLAMS FOR COMFENSITIOIC

After an animated debate on the report of the commit•
tee on this subject, the principal recommendations were
agreed to.

THE MAIN NORTHERN DRAINAGE,

Mr. BAZALGETTE, the engineer to the board, propounded
his scheme for tie main drainage of the metropolis on the
north side of the Thames, in an elaborate report, the read-
ing of which occupied upwards of an hour. It involves
the execution of a gigantic series of public works; at an
estimated aggregate expense of upwards of 1,500,000/.
The entire area from which it is proposed to intercept the
sewage from flowing into the Thames, as at present, com-
prises about 59 square miles, and to drain this immense
district he contemplates the construction of four main
lines of intercepting sewers, which will have the effect of
subdividing the whole into four separate drainage areas—
viz., the northern high level, and the middle level areas,
from which the sewage would be conveyed by gravitation
to high water at Barking-creek ; the low level area, from
which the sewage would be pumped into the high level
outfall, common to the three areas already named ; and
the western area, for which alternative propositions will
be laid before the board for its selection.

The northern high level sewer, as proposed, commences
by a junction with the Fleet sewer at the foot of Hamp-
stead-hill, and proceeds in a continuous line until it reaches
the river Lea, which it crosses by an aqueduct, and where
it is provided with an overflow for the discharge of its
storm waters into that river. The main intercepting sewer
for the middle level area commencee:in the Harrow-road,• •
at Kensal-green, and passes under the Paddington Canal
and Great Western Railway, and along Oxford-street until
it reaches the Fleet, which it intercepts. It then traverses
Clerkenwell, and goes on, passing eventually below the
East and West India Dock Railway, near St. George
Duckett's Canal, at which point a junction will, be effected
with the northern high level sower, with which it will be
carried over the river Lea, near Old Ford, at such an eleva-
tion as to enable it to be continued eastward to Barking-
creek, and there to discharge into the Thames at high
water. In its course it receives two branches, projected
with a view to intercept as much of the sewage as possible,
by gravitation—the first commencing at Curzon-street,
Piccadilly, and joining the main line at King's-road, Gray's-
inn-lane; the second beginning at Commercial-street,
Whitechapel, and forming a junction with the main line
in Green-street. With respect to the low level area, two
alternatives for dealing with its sewage are submitted, the
one treating it as a separate district, the other uniting it
with the western district, for the purpose of conveying the
sewage of both districts by a single channel to Berking-
creek. There will be a pumping station on the eastern
side of the river Loa, near a place called the Abbey Mills,
where the sewage will be lifted to the level of the high level
sewers. As the ultimate object of a scheme of interception
is the purification of the Thames, Mr. Bazalgette is of
opinion that that object cannot bo attained until the chan-
nel of the river is deepened, and its mud banks removed by
the construction of a proper embankment in conjunction
with the scheme of interception ; and, while he submits
plans and estimates for a low level sewer—proceeding along
the Strand, Fleet-street, and eastwards—independent of an
embankment of the Thames, he states that a large amount
of risk and capital may be saved by executing the low level
sewer iu conjunction with an embankment along the north
side of the Thames, and that the execution of both these
works is essential to the full attainment of the object
desired. This statement elicited marked expressions of
approval from the board. He acids that the main difficul-
ties to be encountered in the execution of the northern
drainage and the greatest amount of inconvenience to the
public traffic would occur in the construction of the low
level sewer, along the Strand, Fleet-street, and towards
the east; and this ronte involves the necessity for recon-
structing and reversing the direction of all the branch
sewers on the south side of the line. For the western dis-
tricts two alternative schemes are proposed, involving a
difference in cost of upwards of 258,0001.—0ne, upon the
score mainly of economy, the establishment and mainten-
ance of works for purifying its sewage waters, and then
discharging them into the Thames, within the limits of
the district itself ; the other for conveying sewage to Bark-
ing-creek.
Again, it is proposed to construct an iron covered
aqueduct, similar in appearance and construction to a
tubular bridge, and about a mile and a half in length,
through which the sewage from the high and middle level
sewers will be conveyed over the river Lea, and onwards
to its destination. A reservoir is also contemplated at
Barking crock, capable of containing 7,000,000 cubit" feet,
exclusive of the sewage from the western district, or
9,000,000 cubic feet including it.
The estimated cost of the northern high level sewer is
129,500/. ; the middle level sewer and branches, 214,2001.;
the low level sewer, exclusive of the sewage from the west-
ern district, 253,800'. ; western district, 78,2001. ; main
outfall sewer to Barking, reservoir, and land, 425,800/. ;
sewage works, 90,000/. ; engine-houses, engines, pumps,
&c., 112,0001. ; making a total of 1,303,500/. ; or, if
258,1801. be added—the additional cost of conveying the
sewage from the western district to Barking—the total
cost of the whole of the works recommended is estimated
at 1,561,6301.
On the motion of Mr. CAIIPMAEL, the consideration of
the report of the engineer by the board was fixed for
Wednesday fortnight.

MARKET NEWS.—(This Day.)