, 1873-10-18

"~N n " dLlO OICSDIuOI WuGICUH
some thousands Of acres of the land previ-
ousIy reclaimed by the inhabitants were
temporarily put once again under a consi-
derable depth of water. The great dis
district about to be drained is b0rdered on
the one side by the Adriatic, and lies near
~ midway between Ravennaand Venice.
1t Is some 90 kilometres in length bv
twelve In breadth, and its surface varies
from the condition of wet marsh to a sub
merged morass under a metre in depth of
water. It's superficial area is over $4,000
acres and the work Of draining it is being
carried out by an Anglo-Italian Company
promoted in this country by Messrs.
Cutbill and De Lunga, Of C%annonstreet
the practical operations being conducted
under Mr.. James Longridge, as English, and
the Commentators Bella, as Italian en-
glneer and the amount expected to be ex-
pended being half a million of money, one
molety of the capital being subscribed in
the Italian district itself. The tract has
already some large drains and canals ex-
lstlng-that of the Pc di Goro protecting
1T from the sea-but others are to be cut in
each direction at every kilometre apart,
from which the run of the waters will be
c0nVerged upon the southern or Ravenna
border of the tract at Codogoro, where the
great pumping station will be erected the
drainage waters being there elected into
the VoIano, and thus discharged into the
Adriatic. The whole of the pumps will
be there placed in one great building, and
they are considered to be equal to the dis
charge OF ten days continuous rainfall.
The Pc flows, as is we'll known, upon an
embankment of its own silt, and advantage
will be taken of this to supply, by means
of syphons, water for irrigation in dry sea-
sons, if it be necessary.
The selection for the class of pumps for
the work was a matter of some anxiety,
and special visits were paid by the en-
ginrers to Holland. and other countries,
where drainage operations Of magnitude
were we'll understood, and although wheel
pumps are much used in the Netherlands,
the best Dutch authorities concurred in
the superior advantages of the centrifugal
pumps if they could be made on O compe-
tent scale of dimensions. Messrs. Gwynne
undertook the engagement, and the work
manship and design of their machinery
alike do justice to their enterprise. The
pumps, eight in number, are made In pairs,
each pair being driven by an engine Of 500
horsepower indicated, working under a
boiler pressure of7Olb., and an idea of their
magnitude wi be obtained from the fact
of their collective throw of water being
over 1000 tons per minute.
The following are the exact details of
these important machines. The eight
centrifugal pumps are worked by four
compound condensing engines /; each pair
of engines with cylinders 272 inches diane
ter of high pressure, and 468 inches of
low pressure stroke of engines 2 #. 3
inches; revolutions lis per minute i. b..
p, 500; boiler pressure 70lb. The con-
densers are two in number for each pair
of engines, and are bo!ted to the discharge
of each pump, the water from which pas
ses through the condenser tubes Is inches
in diameter) ; the cooling in each conden-
ser is $50 feet, therefore there are 1900
feet condensing surface for each pair Of
engines. The air pumps are single acting,
Is inches in diameter and 10 inches
stroke. A sluice valve is placed on the
discharge of each pump beyond the con-
denser, and is opened aud closed by
hydraulic power. The two pumps attach
ed to each pair of engines are ga inches in
diameter, with disc 5 feet diameter, the
disc being removable without interference