_Answer._--The engines are started pumping into the ram and cylinder,
whose drain-cocks have previously been opened, and air and water issues
from them; when the air has escaped they are shut off, and then the
great mass of iron and steel begins to tremble and totter and moves
upwards and upwards, and on nearing the limit of its journey the top of
the accumulator lifts a projecting lever which has a small chain
attached to it, the bottom end of the chain is attached to the steam
throttle valve, and when the chain is pulled up at the top the steam is
shut off at the throttle-valve and the engine stops, but will start as
soon as any water is taken from the accumulator.
37. _Question._--Is there any similarity in terms used in hydraulic work
and steam boiler work?
_Answer._--There are several terms common to hydraulics and steam; the
steam boiler might be called an accumulator of power; there is a
slide-valve in hydraulics as in the steam engine, to admit the power and
to allow the exhaust to escape; there are stop-valves and intermediate
valves in hydraulics, as in steam pipes, also air-vessels in each: there
are suction and delivery pipes and valves in each, and relieve valves
also in each; there is a cylinder in each in which the power is
concentrated; there are reversing levers in a hydraulic crane, as in a
steam crane.
38. _Question._--Who invented the atmospheric engine, and how was it
constructed?
_Answer._--Savory, a mining agent, invented the first method, which he
called an engine, of drawing water up from a well by means of a vacuum
which he happened accidentally to discover a method to create, and the
pressure of the atmospheric combined with it. He procured a real steam
boiler with a safety valve and gauge cocks and erected two vessels in
which to create a vacuum; a suction pipe from the bottom of each vessel
led down into a well beneath the vessels, and a valve that opened
upwards was on the end of each pipe. When about to start work, steam
from the boiler was turned into one of the vessels, and kept on until it
was as hot as the boiler itself, while a drain cock was kept open the
while, and when air and water had been forced out of the vessel steam
was shut off, and water from a tank above the vessel was allowed to flow
on it, which soon made a vacuum inside the vessel, and water was sucked
up through the valves opening upwards and delivered into a tank placed
for the purpose. While this performance was in progress, the other
vessel was being charged with steam to repeat the performance, etc. This
is the extent as far as I know of Savory's claim to be the inventor of
the atmospheric engine.