of men to assist you in getting the apparatus under
headway. Take your position in the center rectangle,
back far enough to give the forward edges of the glider
an inclination to tilt upward very slightly. Now start
and run forward at a moderately rapid gait, one man at
each end of the glider assisting you. As the glider cuts
into the air the wind will catch under the uplifted edges
of the curved planes, and buoy it up so that it will rise
in the air and take you with it. This rise will not be
great, just enough to keep you well clear of the ground.
Now project your legs a little to the front so as to shift
the center of gravity a trifle and bring the edges of the
glider on an exact level with the atmosphere. This, with
the momentum acquired in the start, will keep the machine
moving forward for some distance.

Effect of Body Movements.

When the weight of the body is slightly back of the
center of gravity the edges of the advancing planes are
tilted slightly upward. The glider in this position acts
as a scoop, taking in the air which, in turn, lifts it off the
ground. When a certain altitude is reached--this varies
with the force of the wind--the tendency to a forward
movement is lost and the glider comes to the ground.
It is to prolong the forward movement as much as possible
that the operator shifts the center of gravity slightly,
bringing the apparatus on an even keel as it were by
lowering the advancing edges. This done, so long as
there is momentum enough to keep the glider moving, it