whereas the latter is used to designate a turning
movement to the right or to the left.

WHY SHOULD THE ANGLE OF THE BODY CHANGE?
--The first question that presents itself is, why
should the angle of the aeroplane body change?
Why should it be made to dart up and down and
produce a sinuous motion? Why should its nose
tilt toward the earth, when it is descending, and
raise the forward part of the structure while ascending?

The ready answer on the part of the bird-form
advocate is, that nature has so designed a flying
structure. The argument is not consistent, because
in this respect, as in every other, it is not
made to conform to the structure which they seek
to copy.

CHANGING ANGLE OF BODY NOT SAFE.--Furthermore,
there is not a single argument which can be
advanced in behalf of that method of building,
which proves it to be correct. Contrariwise, an
analysis of the flying movement will show that it is
the one feature which has militated against safety,
and that machines will never be safe so long as
the angle of the body must be depended upon to
control the angle of flying.

_Fig. 11a Monoplane in Flight._