oil, preferably of volatile character. From this vessel pipes lead to
two cocks, one for each cylinder; these corks being caused to revolve in
time with the engine-shaft by a chain, M, communicating motion from a
wheel on the engine shaft to a chain-wheel of equal size on the spindle
of the two cocks. The plug of each cock has on its side a small hollow,
which during one part of its revolution presents itself under the
oil-pipe, and receives a charge of oil. During another part of its
revolution, which is timed to correspond with the flow of gaseous
mixture to the cylinder, the hollow of the plug presents itself to the
bend of a pipe leading from the top of the cylinder to a port opening
into the cylinder below the regenerator, in which port are situated
two wires of platinum. These wires are connected with the brushes of a
commutator, K, on the engine-shaft, which commutator is in electrical
connection with the poles of a battery, dynamo-electric machine, or
other source of electricity. Instead of two wires to produce a spark, a
single wire may be arranged to become incandescent at the proper time
for ignition.

The operation of the engine is as follows: Each piston as it ascends
draws into the annular space under it a supply of gas and air in
proportion regulated by the cocks or valves, and as it descends it
forces this charge into the interior of the revolving valve and its
casing, and into the reservoir which communicates therewith. When either
piston is at the top of its stroke, the revolving valve admits to the
upper part of the cylinder a supply of the gaseous mixture from the
reservoir and valve casing, and this passes through the generator. At
the same time a portion of the charge passes by the pipe, and becomes
enriched by admixture of the hydrocarbon oil delivered to it by the
cock. The enriched mixture, in passing the platinum wires, which at that
time give an electrical spark, is ignited, and ignites the charge that