The Wrights’ experiments at Kitty Hawk covered two periods. In 1900 they began flying gliders. Winds proved to be unsatisfactory with the result that the experiments of this year fell far below expectations. They were back in 1901 with a much larger glider. From this model they learned that large surfaces could be controlled almost as easily as smaller ones, provided the control was by manipulation of the surfaces themselves instead of the movements of the operator’s body. In their glider experiments of 1901 they broke all records for distance in gliding. Air lift still troubled the brothers, so Orville rigged up a small wind tunnel made out of an old starch box. Within the box was a balance, the main feature of which was a metal rod that pivoted like a weather vane. The starch box experiment led to the design of the more scientific wind tunnel shown on Page 5. [Illustration: Newspaper comments on the early efforts of the Wright brothers.] In the third glider trials in 1902 the brothers put all their new knowledge to the test with good results. One new feature was a “tail.” The idea of making this tail movable led to the system of control generally used today—the independent control of aileron and rudder. The third series of glider flights was highly successful. The Wright brothers were now convinced they could build a successful power flyer. One of the first requirements was an engine to produce at least eight horsepower and weigh not more than 20 pounds per horsepower. Unable to obtain such an engine, they built one themselves. The plane now took shape with wings having a total span of a little over 40 feet with the upper and lower wings six feet apart. Total weight of the plane was 750 pounds. Although the plane was assembled in Kitty Hawk by September 23, 1903, weather and various mechanical mishaps postponed the day of trial until December 14. On the toss of a coin, Wilbur won the right to make the first trial. The machine climbed a few feet, stalled and fell. Several parts were broken, requiring two days for repairs. There were other minor delays and then came the fateful day of December 17. This time Orville was the pilot. The few spectators stood silently by, little realizing that they were participating in an event that would be “forever known.” Orville lay flat in the pilot’s place with Wilbur running alongside, a hand on a wing, until the machine left the rail. This, in the words of one of the historians of the flight, is what happened: “Signals that all was in readiness were exchanged. The motor turned, the propellers whirled, a restraining wire was released; the machine rolled along a crude runway, then took off under its own power and flew for twelve unbelievable seconds for 120 incredible feet.