1shaft, which slopes and twists like a
screw and gradually descends.
The
lowest of these machines is set in a deep place, which is distant from the
surface of the ground 660 feet.
lowest of these machines is set in a deep place, which is distant from the
surface of the ground 660 feet.
The fourth species of pump belongs to the same genera, and is made
as follows. Two timbers are erected, and in openings in them, the ends of a
barrel revolve. Two or four strong men turn the barrel, that is to say, one
or two pull the cranks, and one or two push them, and in this way help the
others; alternately another two or four men take their place. The barrel
of this machine, just like the horizontal axle of the other machines, has a
drum whose iron clamps catch the links of a drawing-chain. Thus water
is drawn through the pipes by the balls from a depth of forty-eight feet.
Human strength cannot draw water higher than this, because such very
heavy labour exhausts not only men, but even horses; only water-power
can drive continuously a drum of this kind. Several pumps of this kind, as
of the last, are often built for the purpose of mining on a single vein,
but they are arranged differently for different positions and depths.
as follows. Two timbers are erected, and in openings in them, the ends of a
barrel revolve. Two or four strong men turn the barrel, that is to say, one
or two pull the cranks, and one or two push them, and in this way help the
others; alternately another two or four men take their place. The barrel
of this machine, just like the horizontal axle of the other machines, has a
drum whose iron clamps catch the links of a drawing-chain. Thus water
is drawn through the pipes by the balls from a depth of forty-eight feet.
Human strength cannot draw water higher than this, because such very
heavy labour exhausts not only men, but even horses; only water-power
can drive continuously a drum of this kind. Several pumps of this kind, as
of the last, are often built for the purpose of mining on a single vein,
but they are arranged differently for different positions and depths.
A—AXLES. B—LEVERS. C—TOOTHED DRUM. D—DRUM MADE OF
RUNDLES.
E—DRUM IN WHICH IRON CLAMPS ARE FIXED.
E—DRUM IN WHICH IRON CLAMPS ARE FIXED.
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