The steam engine familiarly explained and illustrated; with an historical sketch of its invention and progressive improvement; its applications to navigation and railways; with plain maxims for railway speculators. By the Rev. Dionysius Lardner ... With additions and notes by James Renwick ...

SAVERY AND NEWCOMEN. 53
beneath the feeding boiler E, steam is produced in it above
the surface of the water, which having no escape presses on
the surface so as to force it up in the pipe I. The cock In!eing then opened, the boiling water is forced into the principal boiler D, into which it is allowed to flow until water
issues from the gauge cock G'. When this takes place,
the cock K is closed, and the fire removed from F until
the great boiler again wants replenishing. When the feeding boiling fE has been exhausted, it is replenished from
the cistern c, (fig. 8,) through the pipe F, by opening the
cock M.
(32.) We shall now describe the working apparatus in
which the steam is used as a moving power.
Let v v' (fig. 8) be two steam vessels communicating by
the tubes T T' (marked by the same letters in fig. 7) with
the greater boiler D.
Let s be a pipe, called the suction pipe, descending into
the well or reservoir from which the water is to be raised,
and communicating with each of the steam vessels through
tubes D D' by valves A A' which open upward. Let F be a
pipe continued from the level of the engine of whatever
higher level it is intended to elevate the water. The steam
vessels v v' communicate with the force-pipe F by valves
B B, which open upward, through the tubes E E'. Over the
steam vessels and on the force-pipe is placed a small cistern
c already mentioned, which is kept filled with cold water
from the force-pipe, and friom the bottom of which proceeds
a pipe terminated with a cock G. This is called the condentsing pipe, and can be brought alternately over each steam
vessel. From this cistern another pipe communicates with
the feeding boiler (fig. 7) by the cock a.)''
The communication of the pipes T T' with the boiler can
be opened and closed, alternately, by the regulator a, fig. 7,)
already described.
* This pipe in fig. 9 is represented as proceeding from the force-prpe above
the cistern c.
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