GAS MOTORS AND PRODUCERS.

By C.W. SIEMENS, London.


The cylinder of the engine--assuming that it has only a single-acting
one, placed with its axis vertical--consists of two parts; the upper hot
part being lined with plumbago, fire-clay, or other refractory material,
and the lower part kept cool by a water casing. The cylinder has a trunk
piston working in the lower part, and on its upper side a shield that
almost fills the hot part of the cylinder when the piston is at the
extreme of its upstroke. The trunk-rod of the piston passes through a
stuffing-box in the cylinder bottom, and is connected to a crank on the
engine-shaft; and this (unless multiple cylinders are employed) carries
a heavy fly-wheel. From the lower end of the cylinder there is a passage
which, by means of a rotating or reciprocating slide, is alternately
put in communication with inlets for gas and air (regulated by suitable
cocks or valves) and with a strong receptacle. As the piston, makes its
upstroke, air and gas are drawn into the annular space surrounding its
trunk, and the mixed air and gas are compressed by the downstroke of
the piston, and delivered into the receptacle, in which considerable
pressure is maintained. The receptacle is made of cylindrical form, with
a domed cover of thin sheet metal; so that in case of excessive internal
pressure it can operate as a safety-valve to save the body of the
receptacle from damage. From the upper end of the cylinder there is
a passage that, by means of a rotating or reciprocating slide, is