Every professional aviator has his own ideas as to the design of the
propeller, one of the most important features of flying-machine
construction. While in many instances the propeller, at a casual glance,
may appear to be identical, close inspection will develop the fact that
in nearly every case some individual idea of the designer has been
incorporated. Thus, two propellers of the two-bladed variety, while of
the same general size as to length and width of blade, will vary greatly
as to pitch and "twist" or curvature.
