hour was 10,594 cub. ft. This dredger had also a
complete installation as a suction dredger, the suction pipe being 2
ft. diameter. The fan of the centrifugal pump was 5.25 ft. diameter,
and was driven by the motor of the bucket ladder. The three bucket
dredgers worked with head to the ebb tide. They could also work with
head to the flood tide, but it took so long a time to turn them about
that it was impracticable. The work was for from 13 to 14 hours a day
on the ebb tide. The effective daily excavation averaged 4839 cub.
yds. Each dredger was fitted with six anchors. The excavated cut was
164 ft. wide by 6.56 ft. deep. "Scheldt III." was capable of lifting a
mass 9.84 ft. thick. The suction dredger "Scheldt II." was of the
multiple type, and is stated to be unique in construction. It can
discharge material from a scow alongside, fill its own hopper with
excavations, discharge its own load upon the bank or into a scow by
different pipes provided for the purpose, and discharge its own load
through hopper doors. The machinery is driven by a triple expansion
engine of 300 i.h.p. working the propeller by a clutch. Owing to the
rise and fall in the tide of 23 ft. the suction pipe is fitted with
spherical joints and a telescopic arrangement. The vessel is 157.5 ft.
by 28.2 ft. by 12.8 ft. The diameter of the pump is 5.25 ft. The wings
of the pump are curved, the surface being in the form of a cylinder
parallel to the axis of rotation, the directrix of which is an arc of
a circle of 2.62 ft. radius with the straight part beyond. The suction
and discharge pipes are 2 ft. diameter. A centrifugal pump is provided
for throwing water into the scows to liquefy the material during
discharge. The dredger, which is fitted with electric lights for work
at night, is held by two anchors, to prevent lurching backwards and
forwards; it can work on the flood as well as on the ebb tide, and can
excavate to a depth of 42.65 ft., the output depending upon the nature
of the material. With good material it can fill its tanks in thirty
minutes. To empty the tanks by suction and discharge upon the bank
over the dyke takes about fifty minutes, depending upon the height and
distance to which the material requires to be delivered. The daily
work has averaged eighteen hours, ten trips being made when the
distance from the dredging ground to the point of delivery is about 1
m. When t