e
could, by the use of two propellers, secure a reaction against a greater
quantity of air, and at the same time use a larger pitch angle than was
possible with one propeller; and in the second place by having the
propellers turn in opposite directions, the gyroscopic action of one
would neutralize that of the other. The method we adopted of driving the
propellers in opposite directions by means of chains is now too well
known to need description here. We decided to place the motor to one
side of the man, so that in case of a plunge headfirst, the motor could
not fall upon him. In our gliding experiments we had had a number of
experiences in which we had landed upon one wing, but the crushing of
the wing had absorbed the shock, so that we were not uneasy about the
motor in case of a landing of that kind. To provide against the machine
rolling over forward in landing, we designed skids like sled runners,
extending out in front of the main surfaces. Otherwise the general
construction and operation of the machine was to be similar to that of
the 1902 glider.

When the motor was completed and tested, we found that it would develop
16 horse-power for a few seconds, but that the power rapidly dropped
till, at the end of a minute, it was only 12 horse-power. Ignorant of
what a motor of this size ought to develop, we were greatly pleased with
its performance. More experience showed us that we did not get one-half
of the power we should have had.

With 12 horse-power at our command, we considered that we could permit
the weight of the machine with operator to rise to 750 or 800 pounds,
and still have as much surplus power as we had originally allowed for in
the first estimate of 550 pounds.

Before leaving for our camp at Kitty Hawk we tested the chain drive for
the propellers in our shop at Dayton, and found it satisfactory. We
found, however, that our first propeller shafts, which were constructed
of heavy gauge steel tubing, were not strong enough to stand the shocks
received from a gasoline motor with light fly wheel, although they would
have been able to transmit three or four times the power uniformly
applied. We therefore built a new set of shafts of heavier tubing, which
we tested and thought to be abundantly strong.

We left Dayton, September 23, and arrived at our camp at Kill Devil Hill
on Friday, the 25th. We found there provisions and tools, which had been
shipped by freight several weeks in advance. The buildin