pproached the wall of the building Frank discovered that he could
not get the belt back into the neutral position. In desperation, he
grasped the rear axle with both hands and was dragged a short distance,
attempting to stop the machine, before it struck the wall. He had,
however, sufficiently retarded it so that no damage was done.

This short trial demonstrated some of the weaknesses in the friction
transmission. Since the speed of the surface of the flywheel, in feet
per second, increased in proportion to the distance of the point of
contact from the center, the outer edge of the belt attempted to run
faster than the inner edge. This conflict of forces not only put an
undue load on the motor causing a great loss of power, but it also
created a tendency for the belt to work towards the outer edge of the
flywheel. Conversely, when the operator desired to return the belt to
neutral, it strongly resisted any efforts to slide it toward the center
of the wheel, as Frank had learned from the wall-bumping incident.
Furthermore, the rubber belt on the friction drum had worn so badly
that it had to be replaced at least once during the brief experiments.

[Illustration: FIGURE 18.--IGNITION CHAMBER, switch, and breaker contacts
of the present Duryea engine.]

At this point, Frank and Markham felt that the carriage was anything but
satisfactory. While they were trying to decide what steps should be
taken next, Frank added one last improvement to the engine. Fearing that
the uncooled cylinder might suffer damage from the excessive heat, he
constructed a copper water jacket in two halves, drew them together
around the cylinder with clamping rings and soldered the seams. Asbestos
packing sealed the end joints where the jacket contacted the cylinder.
Thinking back, Frank does not recall that he ever used a water tank with
this engine, though he does remember adding water through the upper
jacket opening. The engine was run only for a few brief periods
following this addition.

Obviously this collection of patchwork could not fulfill their needs for
an engine. First, it would be next to impossible to start if the body
was placed on the running gear, as the flywheel then would be
practically inaccessible. The absence of rings on the piston caused a
further loss of power to the already overloaded engine. The flywheel was
too light. The absence of any form of governor left the operator with no
control over the engine speed. Ignit