1by “rag and chain” pumps.12 When there is but a small quantity, it is
either brought up in buckets or drawn up by chains of dippers or suction
pumps, and when there is much water it is either drawn up in hide bags or
by rag and chain pumps.
either brought up in buckets or drawn up by chains of dippers or suction
pumps, and when there is much water it is either drawn up in hide bags or
by rag and chain pumps.
First of all, I will describe the machines which draw water by chains
of dippers, of which there are three kinds. For the first, a frame is
made entirely of iron bars: it is two and a half feet high, likewise two and
a half feet long, and in addition one-sixth and one-quarter of a digit
long, one-fourth and one-twenty-fourth of a foot wide. In it there are three
little horizontal iron axles, which revolve in bearings or wide pillows of steel.
and also four iron wheels, of which two are made with rundles and the same
number are toothed. Outside the frame, around the lowest axle, is a
wooden fly-wheel, so that it can be more readily turned, and inside the frame
is a smaller drum which is made of eight rundles, one-sixth and one twenty
fourth of a foot long. Around the second axle, which does not project
beyond the frame, and is therefore only two and a half feet and one-twelfth
and one-third part of a digit long, there is on the one side, a smaller toothed
wheel, which has forty-eight teeth, and on the other side a larger drum,
which is surrounded by twelve rundles one-quarter of a foot long. Around the
third axle, which is one inch and one-third thick, is a larger toothed wheel
projecting one foot from the axle in all directions, which has seventy-two
teeth. The teeth of each wheel are fixed in with screws, whose threads are
screwed into threads in the wheel, so that those teeth which are broken can be
replaced by others; both the teeth and rundles are steel. The upper axle
projects beyond the frame, and is so skilfully mortised into the body of
another axle that it has the appearance of being one; this axle proceeds
through a frame made of beams which stands around the shaft, into an iron
fork set in a stout oak timber, and turns on a roller made of pure steel.
Around this axle is a drum of the kind possessed by those machines which
draw water by rag and chain; this drum has triple curved iron clamps,
to which the links of an iron chain hook themselves, so that a great weight
cannot tear them away. These links are not whole like the links of other
chains, but each one being curved in the upper part on each side catches the
one which comes next, whereby it presents the appearance of a double chain.
At the point where one catches the other, dippers made of iron or brass plates
and holding half a congíus13 are bound to them with thongs; thus, if there are
one hundred links there will be the same number of dippers pouring out water.
When the shafts are inclined, the mouths of the dippers project and are covered
on the top that they may not spill out the water, but when the shafts are
vertical the dippers do not require a cover. By fitting the end of the lowest
small axle into the crank, the man who works the crank turns the axle, and at
the same time the drum whose rundles turn the toothed wheel of the second
axle; by this wheel is driven the one that is made of rundles, which
of dippers, of which there are three kinds. For the first, a frame is
made entirely of iron bars: it is two and a half feet high, likewise two and
a half feet long, and in addition one-sixth and one-quarter of a digit
long, one-fourth and one-twenty-fourth of a foot wide. In it there are three
little horizontal iron axles, which revolve in bearings or wide pillows of steel.
and also four iron wheels, of which two are made with rundles and the same
number are toothed. Outside the frame, around the lowest axle, is a
wooden fly-wheel, so that it can be more readily turned, and inside the frame
is a smaller drum which is made of eight rundles, one-sixth and one twenty
fourth of a foot long. Around the second axle, which does not project
beyond the frame, and is therefore only two and a half feet and one-twelfth
and one-third part of a digit long, there is on the one side, a smaller toothed
wheel, which has forty-eight teeth, and on the other side a larger drum,
which is surrounded by twelve rundles one-quarter of a foot long. Around the
third axle, which is one inch and one-third thick, is a larger toothed wheel
projecting one foot from the axle in all directions, which has seventy-two
teeth. The teeth of each wheel are fixed in with screws, whose threads are
screwed into threads in the wheel, so that those teeth which are broken can be
replaced by others; both the teeth and rundles are steel. The upper axle
projects beyond the frame, and is so skilfully mortised into the body of
another axle that it has the appearance of being one; this axle proceeds
through a frame made of beams which stands around the shaft, into an iron
fork set in a stout oak timber, and turns on a roller made of pure steel.
Around this axle is a drum of the kind possessed by those machines which
draw water by rag and chain; this drum has triple curved iron clamps,
to which the links of an iron chain hook themselves, so that a great weight
cannot tear them away. These links are not whole like the links of other
chains, but each one being curved in the upper part on each side catches the
one which comes next, whereby it presents the appearance of a double chain.
At the point where one catches the other, dippers made of iron or brass plates
and holding half a congíus13 are bound to them with thongs; thus, if there are
one hundred links there will be the same number of dippers pouring out water.
When the shafts are inclined, the mouths of the dippers project and are covered
on the top that they may not spill out the water, but when the shafts are
vertical the dippers do not require a cover. By fitting the end of the lowest
small axle into the crank, the man who works the crank turns the axle, and at
the same time the drum whose rundles turn the toothed wheel of the second
axle; by this wheel is driven the one that is made of rundles, which