piston from closing the exhaust valve.

After keying the flywheel to the lower end of the crankshaft, Charles
and Frank decided to make an attempt to run the engine. Carrying it
into a back room, probably during July or August, 1892, they blocked it
up on horses. A carburetor had not yet been constructed, so they
attempted to start the engine by spinning the flywheel by hand, at the
same time spraying gasoline through the intake valve with a perfume
atomizer previously purchased at a drugstore in the Massasoit House.
Repeated efforts of the two men to start the engine resulted in failure.

[Illustration: FIGURE 15.--CONJECTURAL drawing of the free-piston engine
used in the Museum vehicle prior to the present engine. (Drawing by A. A.
Balunek.)]

In the belief that the defects, whatever they might be, could be
remedied after the engine was installed, the Duryeas went ahead and
mounted the engine in the carriage. To do this they shortened the
original reach of the carriage, allowing the engine itself to become the
rear continuation of the reach. The four ears on the front, or open end
of the engine, were bolted to the centrally located frame, with the
bearing blocks in between. This frame, the same one now in the vehicle,
was constructed of two pieces of angle iron, riveted and brazed
together. Greater rigidity was obtained by a number of half-inch iron
rods running from the frame to both front and rear axles. Because of the
absence of any mounting brackets on the engine casting itself, a wooden
block with a trough on top to receive the body of the engine was fitted
between the engine and the axle, while two U-shaped rods secured it with
clip bars and nuts underneath.

Beneath the flywheel was mounted the friction transmission of Charles'
design. This consisted of a large drum, perhaps 12 inches in diameter,
equal in length to the diameter of the flywheel and keyed to a shaft
directly under the center of the crankshaft and parallel to the axles.
(Diameter of drum estimated by examination of existing features.) In
view of the four projections of the frame extending downward and just in
front of the jackshaft position, it is likely that these supported the
four jackshaft bearings. Being a bicycle manufacturer, Charles saw the
need for a differential or balance gear. Accordingly, he purchased from
the Pope Manufacturing Company a very light unit of the type formerly
used on Columbia tricycles, and installed it somewh