both planes are
turned to the same angle, as in position 2, and
flight is initiated without the abnormal oscillating
motion of the body.

But now let us see what takes place the moment
the present type is launched. If, by any error on
the part of the aviator, he should fail to readjust
the tail to a neutral or to a proper angle of incidence,
after leaving the ground, the machine would
try to perform an over-head loop.

The suggested plan does not require this caution.
The machine may rise too rapidly, or its
planes may be at too great an angle for the power
or the speed, or the planes may be at too small an
angle, but in either case, neglect would not turn
the machine to a dangerous position.

These suggestions are offered to the novice, because
they go to the very foundation of a correct
understanding of the principles involved in the
building and in the manipulation of flying machines
and while they are counter to the beliefs of
aviators, as is shown by the persistency in adhering
to the old methods, are believed to be mechanically
correct, and worthy of consideration.

THE LOW CENTER OF GRAVITY.--But we have still
to examine another feature which shows the wrong
principle in the fixed planes. The question is
often asked, why do the builders of aeroplanes
place most of the weight up close to the planes?
It must be obvious to the novice that the lower
the weight the less liability of overturning.

FORE AND AFT OSCILLATIONS.--The answer is,
that when the weight is placed below the planes it
acts like a pendulum. When the machine is traveling
forward, and the propeller ceases its motion,
as it usually does instantaneously, the weight, being
below, and having a certain momentum, continues
to move on, and the plane surface meeting
the resistance just the same, and having no means
to push it forward, a greater angle of resistance is
formed.

In Fig. 19 this action of the two forces is illustrated. The
plane at the speed of 30 miles is at
an angle of 15 degrees, the body B of the machine
being horizontal, and the weig