When a side gust of wind strikes the kite it is moved laterally, in sympathy with the kite, hence the problem of lateral displacement is not the same as with the aeroplane. LATERAL STABILITY IN KITES.--In the latter the power is definitely fixed with relation to the machine itself, and if we should assume that a plane with a power on it sufficient to maintain a flight of 40 miles an hour, should meet a wind moving at the same speed, the machine would be stationary in space. Such a condition would be the same, so far as the angles of the planes are concerned, with a kite held by a string, but there all similarity in action ends. The stabilizing quality of the kite may be perfect, as the wind varies from side to side, but the aeroplane, being free, moves to the right or to the left, and does not adjust itself by means of a fixed point, but by a movable one. SIMILARITY OF FORE AND AFT CONTROL.--Fore and aft, however, the kite and aeroplane act the same. Fig. 48 shows a diagram which illustrates the forces which act on the kite, and by means of which it adjusts its angle automatically. Let us assume that the kite A is flown from a cord B, so that its angle is 22 1/2 degrees, the wind being 15 miles per hour to maintain the cord B at that angle. When the wind increases to 20 miles an hour there is a correspondingly greater lift against the kite. _Fig. 48. Action of Wind forces on Kite._ As its angle is fixed by means of the loop C, it cannot change its angle with reference to the cord, or independently of it, and its only course is to move up higher and assume the position shown by the figure at D, and the angle of incidence of the kite is therefore changed to 15 degrees, or even to 10 degrees. In the case of the aeroplane the effect is similar from the standpoint of power and disposition of the planes. If it has sufficient power, and the angle of the planes is not changed, it will ascend; if the planes are changed to 15 degrees to correspond with the kite angle it will remain stationary. GLIDING FLIGHT.--The earliest attempt to fly by gliding is attributed to Oliver, a Monk of Malmesbury who, in 1065 prepared artificial wings, and with them jumped from a tower, being injured in the experiment. Nearly 700 years later, in 1801, Resnier, a Frenchman, conducted experiments with varying results, followed by Berblinger, in 1842, and LeBris, a French sailor, in 1856. In 1884, J. J. Montgomery, of California, designed a successful glider, and in 1889 Otto and Gustav Lilienthal made the most extended tests, in Germany, and became experts in handling gliders. Pilcher, in England, was the next to take up the subject, and in 1893 made many successful glides, all of the foregoing machines being single plane surfaces, similar to the monoplane. Long prior to 1896 Octave Chanute, an engineer, gave the subject much study, and in that year made many remarkable flights, developing the double plane, now known as the biplane.