[Illustration: Glenn H. Curtiss in his machine ready to start. The fork of the balancing lever is plainly seen at his shoulders. Behind him is the radiator, with the engine still further back.] The motor is raised to a position where the shaft of the propeller is midway between the levels of the main planes, and within the line of the rear edges, so that they have to be cut away to allow the passing of the blades. The motor is of the V type, with 8 cylinders. It is 30 horse-power and makes 1,200 revolutions per minute. The propeller is of steel, two-bladed, 6 feet in diameter, and revolves at the same speed as the shaft on which it is mounted. The high position of the engine permits a low running gear. There are two wheels under the rear edges of the main planes, and another is placed half-way between the main planes and the forward rudder, or elevator. A brake, operated by the pilot’s foot, acts upon this forward wheel to check the speed at the moment of landing. Another type of Curtiss machine has the ailerons set in the rear of the main planes, instead of between them. The Curtiss is the fastest of the biplanes, being excelled in speed only by some of the monoplanes. It has a record of 51 miles per hour. THE CODY BIPLANE. The Cody biplane has the distinction of being the first successful British aeroplane. It was designed and flown by Captain S. F. Cody, at one time an American, but for some years an officer in the British army. It is the largest and heaviest of all the biplanes, weighing about 1,800 lbs., more than three times the weight of the Curtiss machine. Its main planes are 52 feet in lateral spread, and 7 feet 6 inches in width, and are set 9 feet apart. The combined area of these sustaining surfaces is 770 square feet. The upper plane is arched, so that the ends of the main planes are slightly closer together than at the centre. The elevator is in two parts placed end to end, about 12 feet in front of the main planes. They have a combined area of 150 square feet. Between them and above them is a small rudder for steering to right or left in conjunction with the large rudder at the rear of the machine. The latter has an area of 40 square feet. There are two small balancing planes, set one at each end of the main planes, their centres on the rear corner struts, so that they project beyond the tips of the planes and behind their rear lines. [Illustration: The Cody biplane in flight. Captain Cody has both hands raised above his head, showing the automatic stability of his machine.] The biplane is controlled by a lever rod having a wheel at the end. Turning the wheel moves the rudders; pushing or pulling the wheel works the elevator; moving the wheel from side to side moves the balancing planes.