momentum
enough to keep the glider moving, it will remain afloat.

If you shift your body well forward it will bring the front edges of
the glider down, and elevate the rear ones. In this way the air will be
"spilled" out at the rear, and, having lost the air support or buoyancy,
the glider comes down to the ground. A few flights will make any
ordinary man proficient in the control of his apparatus by his body
movements, not only as concerns the elevating and depressing of the
advancing edges, but also actual steering. You will quickly learn,
for instance, that, as the shifting of the bodily weight backwards
and forwards affects the upward and downward trend of the planes, so a
movement sideways--to the left or the right--affects the direction in
which the glider travels.

Ascends at an Angle.

In ascending, the glider and flying machine, like the bird, makes an
angular, not a vertical flight. Just what this angle of ascension may be
is difficult to determine. It is probable and in fact altogether likely,
that it varies with the force of the wind, weight of the rising body,
power of propulsion, etc. This, in the language of physicists, is the
angle of inclination, and, as a general thing, under normal conditions
(still air) should be put down as about one in ten, or 5 3/4 degrees.
This would be an ideal condition, but it has not, as vet been reached.
The force of the wind affects the angle considerably, as does also the
weight and velocity of the apparatus. In general practice the angle
varies from 23 to 45 degrees. At more than 45 degrees the supporting
effort is overcome by the resistance to forward motion.

Increasing the speed or propulsive force, tends to lessen the angle at
which the machine may be successfully operated because it reduces the
wind pressure. Most of the modern flying machines are operated at an
angle of 23 degrees, or less.

Maintaining an Equilibrium.

Stable equilibrium is one of the main essentials to successful flight,
and this cannot be preserved in an uncertain, gusty wind, especially by
an amateur. The novice should not attempt a glide unless the conditions
are just right. These conditions are: A clear, level space, without
obstructions, such as trees, etc., and a steady wind of not exceeding
twelve miles an hour. Always fly against the wind.

When a reasonable amount of proficiency in the handling of the machine
on level ground has been acquired the field of practice may be changed