n on a rotating
crankshaft which was mounted eccentrically to the axis of rotation
of the cylinders. The crankshaft carried a pinion gearing with an
internally toothed wheel on the transmission shaft which carried the
air-screw. The combustible mixture, emanating from a common supply pipe,
was led through conduits to the front ends of the cylinders, in which
the charges were compressed before being transferred to the working
spaces through ports in tubular extensions carried by the pistons.
These extensions had also exhaust ports, registering with ports in the
cylinder which communicated with the outer air, and the extensions slid
over depending cylinder heads attached to the crank case by long studs.
The pump charge was compressed in one end of each cylinder, and the
pump spaces each delivered into their corresponding adjacent combustion
spaces. The charges entered the pump spaces during the suction period
through passages which communicated with a central stationary supply
passage at one end of the crank case, communication being cut off when
the inlet orifice to the passage passed out of register with the port
in the stationary member. The exhaust ports at the outer end of the
combustion space opened just before and closed a little later than the
air ports, and the incoming charge assisted in expelling the exhaust
gases in a manner similar to that of the earlier types of two-stroke
cycle engine; The accompanying rough diagram assists in showing the
working of this engine.

Exhibited in the Paris Aero Exhibition of 1912, the Laviator two-stroke
cycle engine, six-cylindered, could be operated either as a radial or
as a rotary engine, all its pistons acting on a single crank. Cylinder
dimensions of this engine were 3.94 inches bore by 5.12 inches stroke,
and a power output of 50 horse-power was obtained when working at a rate
of 1,200 revolutions per minute. Used as a radial engine, it developed
65 horse-power at the same rate of revolution, and, as the total weight
was about 198 lbs., the weight of about 3 lbs. per horse-power was
attained in radial use. Stepped pistons were employed, the annular space
between the smaller or power piston and the walls of the larger cylinder
being used as a charging pump for the power cylinder situated 120
degrees in rear of it. The charging cylinders were connected by short
pipes to ports in the crank case which communicated with the hollow
crankshaft through which the fresh gas was su