and Drift consider only the air pressures. They
do not take into account the fact that momentum
takes an important part in the translation of an
object, like a flying machine.

A mass of material, weighing 1000 pounds while
at rest, sets up an enormous energy when moving
through the air at fifty, seventy-five, or one hundred
miles an hour. At the latter speed the movement
is about 160 feet per second, a motion which
is nearly sufficient to maintain it in horizontal
flight, independently of any plane surface.

Such being the case, why take into account only
the angle of the plane? It is no wonder that
aviators have not been able to make the theoretical
considerations and the practical demonstrations
agree.

WHY TABLES OF LIFT AND DRIFT ARE WRONG.--
A little reflection will show why such tables are
wrong. They were prepared by using a plane
surface at rest, and forcing a blast of air against
the plane placed at different angles; and for determining
air pressures, this is, no doubt, correct.
But it does not represent actual flying conditions.
It does not show the conditions existing
in an aeroplane while in flight.

To determine this, short of actual experiments