How It Flies; or, The Conquest of the Air / The Story of Man's Endeavors to Fly and of the Inventions by Which He Has Succeeded

by Richard Ferris

Diagram of Bleriot monoplane, showing controlling lever L and bell-shaped drum C, to which all controlling wires are attached. When the bell is rocked back and forward the elevator tips on the rear plane are moved; rocking from side to side moves the stabilizing tips of the main plane. Turning the bell around moves the rudder.

The Marmonier gyroscopic pendulum, devised to secure automatic stability of aeroplanes. The wheels are driven by the aeroplane motor at high speed. The pendulum rod is extended upward above the axis and carries a vane which is engaged by any gust of wind from either side of the aeroplane, tending to tilt the pendulum, and bringing its gyroscopic resistance into play to warp the wings, or operate ailerons.

The caution shown by these experienced aviators cannot be too closely followed by a novice. These men do not say that their assiduous practice on the ground was the fruit of timidity. On the contrary, although they are long past the preliminary stages, their advice to beginners is uniformly in the line of caution and thorough practice.

When the aeroplane is steered to the left, the pendulum swings to the right and depresses the right side of the plane, as in (c). The reaction of the air raises the right side of the plane until both surfaces are perpendicular to the inclined pendulum, as in (d).

Diagrams showing action of Marmonier gyroscopic pendulum.

Even after one has become an expert, the battle is not won, by any means. While flying in calm weather is extremely pleasurable, a protracted flight is very fatiguing; and when it is necessary to wrestle with gusts of high wind and fickle air currents, the strain upon the strongest nerve is a serious source of danger in that the aviator is liable to be suddenly overcome by weariness when he most needs to be on the alert.

In that inclined position the aeroplane makes the turn, and when the course again becomes straight, both the gyroscopic and centrifugal forces cease, and the pendulum under the influence of gravity becomes vertical. In this position it is inclined to the left with respect to the planes, on which its effect is to depress the left wing and so right the aeroplane, as in (e).

Diagram showing action of Marmonier gyroscopic pendulum.