AIR-ESCAPE. A simple and ingenious contrivance for letting
off the air from water-pipes. If a range of water-pipes be led
over a rising ground, it will be found that air will collect in
the hi,-her parts and obstruct the progress of the water, to remedy
which inconvenience the air-escape is employed. A hollow vessel
is attached to the upper part of the pipe, in the top of which
vessel there is fixed a ball cock, adjusted in such a way that,
when any air collects in the pipe, it will ascend into the vessel,
and, by displacing the water, cause the ball to descend, and thus
open the cock, when the air is allowed to escape. No water, however,
can escape, for, when that fluid rises in the vessel above a certain
height, the ball rises and shuts the cock; new air then collects,
displaces the water, lowers the ball the cock is opened and it
a am escapes.