Evening capital. (Annapolis, Md.) 1884-1910, 1892-09-22
ANNAPOLIS Md THURSDAY EVENING, sEPTEMBERaa 1sea.
SEWAGE OF LONDON.
1T IS TAKEN OUT TO SEA AND SCAT
TERED OVER THE WAVES.

Method of Separating the sludge from
the Effiuent-Ciean ships.
'Oh, how unpleasant The idea of go
ing to sea with sludgeg" On the con-
trary, you know nothing of it The
deck of the sludge ship is broad and
clean; the deck house or ''saloon" small
but comfortable; on the bridge fresh
breeze is blowing; the sunlight sparkles
brightly on the ruffied surface of the
river, and you scarce can realize that
this fine steamer is carrying thousand
tons of London sludge ont to sea. Yet
such is the fact The idea that the
''mud barges" Of the county council,
which take out the precipitated portion
of London sewage to the Barrow deep,
are simply dirty dredges is quite mis-
take. They are powerful twin screw
steamships, worked by two sets of triple
expansion engines, and fitted with three
large tanks, kept covered. and abso-
lutely free from nuisance to anybody,
even to the seamen on board. They can
make two trips out to sea in every
twenty-five hours, steaming about ten
knots, and, as matter of fact, they
thus dispose of Al 900 tons Of slndge in
week.
The sludge is precipitated by treat
ing the sewage with lime and sulphate
of iron. First, six huge cages catch
debris, such as sticks and dead rats and
cells, ETC., in the great rushing sewers
which drain London. This rubbish is
burned in Instructors at the rate of
something like hundred tons week;
then the black river of sewage is stirred
in tanks with lime-or, more correctly,
lime water-in the proportion of about
81 grains to the gallon. The effect of
the lime is to precipitate matter in sus-
pension and solution and also to deodor-
ize. You may take smelling bottle
with you IL you like, but with plenty of
lime about you will hardly need it. But
walking on along the top OF the twenty
seven feet wide sewer, which is probably
to become beautiful boulevard for
Barking, one comes to the sulphate Of
iron "shop," where $50 tons at time
are received, and where, after being dis
solved in the proper proportion as di-
rected by the chemist in charge, it, too,
finds its way to the swift river of sew
age.
But then comes pause In the rivers
mad career. 1t is admitted through the
Penstock chamber-that is, a building
with number of iron gates-to set of
covered precipitating channels, where it
can leisurely mediate after its wild
rushings from London. Here in its
quiet bed the lime and iron, in casting
down the solid portions, can take full
effect. and the clear portion Of the liquid
at the top-now called the effluent--
is let off over the head of wall at the
end of the chamber to a channel at the
other side; whence, gathering speed
again, it rushes to reservoir, from
which at ebb tide it joins the Thames.
The sludge passes through pipes from
the bottoms of the precipitating cham
bers to another reservoir, whence 1t is
pumped to the tanks in the sludge
ships and conveyed to sea.
The effect on the river is most salts
factory. On the testimony of the har-
Dor master it is cleaner now than 1t has
been for some years, while Mr.. Thudi-
chum, the chemist at the Barking "out-
fall" works, joyfully maintains 1t has
80 per cent. of oxygen, which it has not
rejoiced in for some summers past, But
the clean foreshore and the scent Of sea-
weed at Barking, and the much purer
looking water in the Thames itself, are
proofs to the uninitiated of the success
of the new" system.
That system is only now getting into
full working order. The county coun-
ell have added two more ships. to the
fleet, making now five in all; and they
are conveying some 40, 900 tons of sludge
out to sea every week. -Four ships are
constantly at work day and night, and
one takes its turn of a rest week for
painting, repairs, etc., and affording q
lighter time for the men. These are
sailors, and sleep on board, regular
watches being kept, except one twenty
four hours in every seven days, when
they are allowed off duty.
The discharging ground of the steam
ers is the Barrow deep, some miles be-
yond the More light. The deep is an
unused channel, the north bound vessels
taking course considerably to the left
and southwark ships far to the right.
The channel has been buoyed by the
council, and no captain may commence
dischargipg until he has passed the
North Knot buoy. The discharge Is
quickly effected by opening valves in the
vessels bottom; the principle being
much the same rs that used on the self
emptying ifeboat- which, indeed, is but
an adaptation of the wthat water finds
its own level, the bottom Of the tanks
being built on level with the sea. The
valves are easily opened from the deck,
and SO quick is their action that the
whole thousand tons can be- discharged
In seven minutes, Generally the time
occupied, however, is longer, the vessel
perhaps steaming ten miles while empty
ing her strange cargo. The white wake
Of the ship is discolored, gulls hover
pver it, and then among the tumbling
waves and the fresh breeges the sludge
is gone.
The mind can hardly grasp the fact
that hundred million gallons Of sewage
pour down the huge drain to Barking
every twenty-four hours. But If we
think for moment that this immense
mass of sludge would, but for the ships,
have been discharged into the Thames
between Gravesend and London bridge,
and be washing backward and forward
with the tides, and that this would be
always going on month after month. we
l.