The peculiar aeroplane illustrated on this page is that of M. Givaudan. It has recently been constructed at Vermorel. It is of the multicellular type, and consists of two concentric drums mounted near the ends of a body framework that passes through the center of each, and carries at its forward end a tractor screw. These drums are united by small planes spaced uniformly apart, thus forming a cellular structure. The front cell thus formed is movable in every direction while the rear one is stationary. The carrying surfaces of this machine are so formed, that the machine will have the same amount of supporting surface whatever its lateral inclination may be, so that when it tips to one side in making a turn, or from any other cause the weight carried per square foot of surface chains the same; while, on the other hand, the center of gravity being situated below the center of pressure, the machine will return automatically to its normal position and be in equilibrium. The two cells are laced sufficiently far enough apart, so that the front one will not interfere seriously with the one at the rear. There are no rudders, the movement of the front cell both sideways and up and down being used in place of these to direct the machine both laterally and in a vertical plane.
The Givaudan circular aeroplane a new French machine of novel design.
The radiating planes of the drums act as carrying and stabilizing surfaces. Only the projecting surface of these radiating planes is counted upon as useful carrying surface. Within both the front and rear drums there is a horizontal cross shaft supported upon the main frame. The front cell rests on the main frame by a bearing, which makes it possible for this cell to oscillate about a vertical axis, while the horizontal shaft just mentioned can oscillate upon a horizontal axis.
Inclination of the front cell in a vertical direction varies the angle of incidence, and causes the machine to rise or descend; it thus takes the place of the horizontal rudder. Inclination of the cell in the horizontal direction fulfills the role of the vertical rudder. This double movement of the cell is obtained by means of a rod connecting two levers of sufficient length to make the operation of the cell possible without too great fatigue. The levers have a band-brake arrangement to hold the cell in the position in which it is set.
The machine rests on four wheels, the front pair of which can be turned in order to steer the machine. The wheels are fitted with suitable springs to absorb the shock when landing. The propeller is 2.4 meters (7.87 feet) in diameter, and is driven from the motor through reduction gears. The motor is a special eight cylinder V engine of the air-cooled type. The bore and stroke are 90 and 120 millimeters (3.6 and 4.8 inches) respectively. The motor develops 40 horse-power and weighs 80 kilogrammes (176 pounds) including the fly-wheel, two carburetors, and magneto. All the valves are mechanically operated from a single camshaft. This motor, notwithstanding its light weight and the feet that it is air-cooled, has been run several hours consecutively. M. Givaudan is one of the first men to construct a motor of the V type and place it upon the market.
This new aeroplane is very interesting, but it is doubtful whether a freakish machine of this kind can be made to operate satisfactorily. If any successful trials are made, we shall be glad to apprise our readers of the fact.
Originally appeared in Scientific American, 100,, June 5, 1909, p. 421.