of energy necessary to set such heavy wheels spinning at a high
velocity. The last experiment with these wheels was made when a
head wind was blowing at the rate of about ten miles an hour.
It was rather unsteady, and when the machine was running at its
greatest velocity, a sudden gust lifted not only the front end,
but also the heavy front wheels completely off the track, and
the machine falling on soft ground was soon blown over by the
wind.'

Consequently, a safety track was provided, consisting of squared
pine logs, three inches by nine inches, placed about two feet
above the steel way and having a thirty-foot gauge. Four extra
wheels were fitted to the machine on outriggers and so adjusted
that, if the machine should lift one inch clear of the steel
rails, the wheels at the ends of the outriggers would engage the
under side of the pine trackway.

The first fully loaded run was made in a dead calm with 150 lbs.
steam pressure to the square inch, and there was no sign of the
wheels leaving the steel track. On a second run, with 230 lbs.
steam pressure the machine seemed to alternate between adherence
to the lower and upper tracks, as many as three of the outrigger
wheels engaging at the same time, and the weight on the steel
rails being reduced practically to nothing. In preparation for
a third run, in which it was intended to use full power, a
dynamometer was attached to the machine and the engines were
started at 200 lbs. pressure, which was gradually increased to
310 lbs per square inch. The incline of the track, added to the
reading of the dynamometer, showed a total screw thrust of 2,164
lbs. After the dynamometer test had been completed, and