Engineering Wonders of the World
Volume III

FLYING MACHINES OF TO-DAY. 21 THE VOISIN BIPLANE. This machine, which came into prominence at the beginning of 1908 as the first successful rival to the Wrights’ Flier, is based, as regards its general lines, on the cellular glider devised in 1898 by Mr. Octave Chanute. It consists of two superposed main decks, 33 feet by 6 feet 5 inches (total area about 450 square Fig. 2.—DIAGRAM OF VOISJN BIPLANE. feet), set 5 feet apart; two smaller superposed decks, 8 feet by 6J feet (total area about 110 square feet), connected to the main decks by a rigid framework, and situated about 13 feet to the rear to form a tail; an elevator (total area about 50 square feet) mounted 4| feet in front of and on a level with the lower main deck on the end of a projecting girder, in which are situated the pilot’s seat and the control gear. The “ tail ” is closed at each side by two vertical curtains, and the main decks are united by four vertical curtains, extending about three-quarters of the distance from the front of the trailing edge. The pur- pose of these curtains is to give vertical stability and obviate the need for warping of the decks or the use of balancing planes. A single vertical rudder inside the tail serves for horizontal steering (Fig. 2). Power is supplied by a 50 horse-power engine geared direct to a single high-speed propeller astern of the main decks. The decks are all curved—the curve depth being one- fifteenth of the fore and aft width of the deck —and covered on the lower side only of the ribs, which are attached to two main cross- spars. The elevator is double surfaced, its horizontal pivot passing between the two surfaces. The machine runs on four wheels, two under the main decks and two under the tail. When at rest, the decks make an angle of 8° with the horizontal, and lift at a speed of about 30 miles per hour. When the machine has risen into the air and the speed is increased, this angle diminishes to about 2°. A very interesting feature of the Voisin aeroplane is control, of which a diagrammatic sketch (Fig. 3) is given. A steering wheel of motor-car type operates a horizon- the steering Voisin Steering Control. tai rod, which can be moved back- wards and forwards, and also revolved, in sockets on the body. The rod is connected Fig. 3.-DIAGRAM SHOWING STEERING CONTROL OF VOISIN BIPLANE. through a universal joint and a second rod to the elevator. On a drum mounted on the steering pillar are wound the wires controlling the vertical rudder in the tail. The driver therefore controls both ver- tical and horizontal movements of the aero- plane by the same steering wheel. The Voisins claim that the cellular principle is inherently stable, and that it makes for ease of control and safety in descent. The utility of vertical curtains has been questioned. It is main- tained in some quarters that they decrease