In the latter part of the Sixteenth, or beginning of the Seventeenth
Century a machine which is entitled to particular notice on account of
its being, as claimed, the first one of the kind to be _self-acting_,
for raising water was in use in Italy. It is ascribed to Gironimo
Finugio who put one in operation at Rome in 1616.
[Illustration]
Between the illustration and the following description its operation
may be clearly understood. On a pulley S, are suspended by a rope
two buckets A and B, of unequal dimensions. The smaller one B, is
made heavier than A when both are empty, but lighter when they are
filled. It is required to raise by them part of the water from the
spring or reservoir E, into the cistern Z. As the smaller Bucket B,
by its superior gravity, descends into E, (a flap valve in its bottom
admitting the water), it consequently raises A into the position
represented in the figure. A pipe F, then conveys water from the
reservoir into A, the orifice or bore of which pipe is so proportioned,
that both vessels are filled _simultaneously_. The larger bucket then
preponderates, descending to O, and B at the same time rising to the
upper edge of Z, when the projecting pins O O, catch against others on
the lower sides of the buckets, and overturn them at the same moment.
The bails or handles are attached by swivels to the sides, a little
above their center of gravity. As soon as both buckets are emptied,
B again preponderates, and the operation is repeated without any
attendance, so long as there is water in E and the apparatus continues
in order.
In Moxon’s machine, the buckets were filled by two separate tubes of
unequal bore; the orifices being covered by valves to prevent the
escape of water while the buckets were in motion; these valves were
opened and closed by means of cords attached to the buckets. The efflux
through F in the figure, may easily be stopped as soon as A begins to
descend, by the action of either bucket on the end of a lever attached
to a valve, or by other obvious contrivances. The water discharged
from A, runs to waste through a channel provided for that purpose.
These machines are of limited application, since they require a fall
for the descent of A, equal to the elevation to which the liquid is
raised in B. They may however be modified to suit locations where a
less descent only can be obtained. Thus, by connecting the rope of B to
the periphery of a large wheel, while that of A is united to a smaller
one on the same axis, water may be raised higher than the larger
bucket falls, but the quantity raised will of course be proportionally
diminished. In the face of these securing advantages it has fallen into
disuse; it was much too complex and cumbersome, and of too limited
application.
The principle of self-action in all these machines is no modern
discovery, for it was described by Hero of Alexandria, who applied it
to the opening and closing the doors of a temple, and to other purposes.