The Boy's Book of New Inventions

by Harry E. Maule

CURTISS BIPLANE

The Curtiss biplane, which we have seen has had a great deal to do with the development of aviation, is one of the simplest and most successful machines known to-day. The main planes of the regular-sized machines have a spread of 26-1/2 feet, are set 5 feet apart, and have a depth from front to rear of 4-1/2 feet. The total wing area is 220 feet. The direction rudder is a single vertical vane at the rear, which is turned by the steering wheel connected by cables. The elevation rudder consisting of one horizontal plane 24 square feet in area is at the front and is turned up or down by the pilot as he desires to sail up or down, by means of a long bamboo pole connecting the elevation rudder with his pilot wheel. He pushes the wheel forward or back to rise or descend, while he twists it from right to left to turn in either of those directions. The side-to-side balance was maintained in the early Curtiss machines by flexible wing tips, but these later were replaced by ailerons placed between and at the outer tips of the main planes. Each aileron had an area of 12 square feet and they were operated by a brace fitted to the operator's body. Thus, if the machine tipped to the right, the operator would swing to the left, turn the ailerons, and right the machine. In some later Curtiss biplanes these ailerons were replaced by others, like flaps attached to the rear outer edges of the main planes. By raising the flaps on one side and lowering them on the other the balance was well preserved.

As before stated, these machines are driven by Curtiss engines. In most of them the engines are 4-cylinder, 25-horsepower motors. The cylinders in this type, of course, are stationary, but the engine shaft is directly connected with the 6-foot propeller at the rear, which makes 1,200 revolutions per minute. The pilot sits between the two main planes of his engine. On large Curtiss machines seats for as many as three passengers have been arranged at the sides of the pilot.

The most important work Curtiss has done in the last few years is the development of the hydro-aeroplane, which has been explained.

VOISIN BIPLANE

The next biplane with which we are familiar is the Voisin, which Henri Farman demonstrated as the first really successful aeroplane seen in Europe. This machine was a standard of what was called the cellular type because it was composed of cells, like a box kite. The two main planes, which were the same size, 37 feet by 6-1/2 feet, were connected at the outer edges so as to make the plane a closed cell—i. e., a box with the ends knocked out. Two other vertical surfaces between the main plane gave the machine the appearance of three box kites side by side. The tail out behind was composed of a square cell. In the centre of it was a vertical vane for steering it from right to left, while out in front was a single horizontal rudder for raising or lowering the plane. The control was much the same as in the Curtiss machine. The steering wheel turned the plane from right to left, and was connected by a rod with the elevator, so that by pushing it forward or back, the machine was raised or lowered. There was no device for maintaining a side-to-side balance as the cell formation was supposed to keep the machine on an even keel. The motor drove a propeller at the rear.

The later Bordeaux type of Voisin which was built for military purposes does away with the side curtains and box tail. On the outer rear edge of the upper main plane are ailerons for maintaining the balance, which are operated by foot pedals. The elevator is a single horizontal plane at the rear of the tail, while the direction rudder is a vertical plane beneath it. This machine carries two persons, and is frequently driven by a Gnome engine.

Still another and later type of the Voisin Bordeaux is the front control. In this the ailerons are used as previously described, but also there are side curtains enclosing the outer edges of the main planes. Out in front at the end of a long framework or fuselage are the horizontal elevating planes, and the vertical direction planes. Both these machines have double control systems.

FARMAN BIPLANE

Dissatisfied with the work of his first Voisin biplane in the early days of flying Henri Farman designed and built a machine that bore his own name, of which the military type is now looked upon with great favour by many of the European experts.