tific side of it. But we soon found the work so
fascinating that we were drawn into it deeper and deeper. Two testing
machines were built, which we believed would avoid the errors to which
the measurements of others had been subject. After making preliminary
measurements on a great number of different-shaped surfaces, to secure a
general understanding of the subject, we began systematic measurements
of standard surfaces, so varied in design as to bring out the underlying
causes of differences noted in their pressures. Measurements were
tabulated on nearly 50 of these at all angles from zero to 45 degrees at
intervals of 2-1/2 degrees. Measurements were also secured showing the
effects on each other when surfaces are superposed, or when they follow
one another.

Some strange results were obtained. One surface, with a heavy roll at
the front edge, showed the same lift for all angles from 7-1/2 to 45
degrees. A square plane, contrary to the measurements of all our
predecessors, gave a greater pressure at 30 degrees than at 45 degrees.
This seemed so anomalous that we were almost ready to doubt our own
measurements, when a simple test was suggested. A weather-vane, with two
planes attached to the pointer at an angle of 80 degrees with each
other, was made. According to our tables, such a vane would be in
unstable equilibrium when pointing directly into the wind; for if by
chance the wind should happen to strike one plane at 39 degrees and the
other at 41 degrees, the plane with the smaller angle would have the
greater pressure, and the pointer would be turned still farther out of
the course of the wind until the two vanes again secured equal
pressures, which would be at approximately 30 and 50 degrees. But the
vane performed in this very manner. Further corroboration of the tables
was obtained in experiments with the new glider at Kill Devil Hill the
next season.

In September and October, 1902, nearly 1,000 gliding flights were made,
several of which covered distances of over 600 feet. Some, made against
a wind of 36 miles an hour, gave proof of the effectiveness of the
devices for control. With this machine, in the autumn of 1903, we made a
number of flights in which we remained in the air for over a minute,
often soaring for a considerable time in one spot, without any descent
at all. Little wonder that our unscientific assistant should think the
only thing needed to keep it indefinitely in the air would be a coat of
f