and aft control of an airship. Lateral stability is secondary to t

caused to oscillate on a vertical fore and aft plane while in flight. The bird has one important advantage, however, in

hange in the angle of the wing is by changing the angle of the body. To be consistent the aeroplane should be

orrespond with the direction of the flying start. When it alights the body is thrown so that its brea

care should be taken to distinguish between the terms angle and direction of flight. The former has reference to the up a

he aeroplane body change? Why should it be made to dart up and down and produce a sinuous motion? Why should it

ned a flying structure. The argument is not consistent, because in this respect, as

which proves it to be correct. Contrariwise, an analysis of the flying movement will show that it is the one feature which has militated

Monoplane

A is going at 40 miles per hour, the second, B, at 50, and the third, C, at 60 miles. The body in A is nearly ho

d of the frame must be raised, which is done by giving the tail an angle of incidence, otherwise, as the upper side of the

Angles

of the frame is now actually above the plane of flight. In order, now, to change the angle

and the air striking its lower side, causes an upward movement of the frame at that e

nd diagram, is elevated so as to depress the rear

lose control of the mechanism, or it should become deranged or "stick," conditions

until it is vertical, and then, in all probability, as its propelling power is not sufficient to hold it in that position,

to the body in such a manner as to make the disposition of its angles synchronous with the tail. In other words, see how a

nes on Non-c

e same angle, which we will assume to be 15 degrees, this being the imaginary angle for illustrati

t 10 degrees, and the speed 60 miles an hour, whi

egrees but the speed is increased to 80 miles per hour, b

he changing of the planes to a greater angle would raise the

ent with Non-

in the three positions respectively, as in Fig. 13, but now the power has been re

to move the planes. When the machine begins to lose its momentum it will descend on a curve shown, for instan

Utilizing

factor, and the machine now begins to travel rearwardly. (Fig. 16.) It has still the entire supporting surfac

e nearly in accord with the true flying principle as given by nature than the

d never be taken from it. While it may be impossible to prevent a machine from coming down, it can be

Reversi

cause it to fly upside down. It does not present any means whereby dare-devil stunts can be perf

advantages it possesses. In these illustrations we have used, for convenience only

ry to launching. Position 2 represents the negative angle at which the tail is thrown, which movement depresses the rear end of the f

ing changing

lanes in a neutral position, as represented in position 1. When sufficient speed had been attained both planes are tu

on the part of the aviator, he should fail to readjust the tail to a neutral or to a proper an

lanes may be at too great an angle for the power or the speed, or the planes may be at too s

involved in the building and in the manipulation of flying machines and while they are counter to the beliefs of aviators, as i

fixed planes. The question is often asked, why do the builders of aeroplanes place most of the weight up clos

ward, and the propeller ceases its motion, as it usually does instantaneously, the weight, being below, and having a certain momentum, continues to

ed of 30 miles is at an angle of 15 degrees, the body B of the machine being

20, and we now have, as in the second figure, a new angle of incidence, which is 30 degrees, instead of 12. It will be unders

when Propeller

tion checked by the banking action of the plan it will again swing back, and again c

ng the frame on an even keel. Being nearly horizontal while in flight, if not a

gested form, let us see wherein it will prevent this pendulous motion

chronously m

e B and the tail a, so they are adjustable simultaneously at the same

y to move upwardly, the same as the forward end, hence, when the weight seeks, in this case to go on, it acts on

be placed low, and thus still further aid in making a compact machine. By increasing the area of the tail, and making that a true supporting surface, instead of a mere