In May, 1900, Wilbur Wright wrote a letter to Octave Chanute, living in Chicago, who had written _Progress in Flying Machines_. Though Chanute was better known in engineering circles by his work for certain western railroads, as well as for having built the Kansas City bridge and the Chicago stockyards, his book, a reprint of his articles published from 1891 to 1893, had made him probably the best authority on the history of aeronautics. Thinking Chanute would be interested, Wilbur told him in his letter of a plan he had for experimenting with a man-carrying kite by means of which, Wilbur thought, one would be able to get hours of practice in operating a machine in the air. He proposed the use of a high tower from the top of which a cable would lead to the man-carrying kite. He described to Chanute, in his letter, the system of control to be used in the kite--the warping of wings for lateral control, and the shifting of the upper surface backward and forward for longitudinal control--the same system used in the five-foot kite tested the previous August. Then he asked Chanute if he had any information as to locations where winds suitable for carrying on such experiments might be found. (This letter from Wilbur marked the beginning of an acquaintance and correspondence with Chanute that lasted for a number of years.) Chanute suggested San Diego, California, and St. James City (Pine Island), Florida, to be considered because of the steady sea breezes. But, on the other hand, he pointed out that, since those places were deficient in sand hills, perhaps even better locations could be found on the Atlantic coast of South Carolina or Georgia. [Illustration: THE 1902 GLIDER. The Wrights are testing the efficiency of the 1902 glider by flying it as a kite--September 19, 1902.] When the rush of the spring trade in bicycles began to subside, giving them more time for other interests, the Wrights again took up with enthusiasm the study of equilibrium. Each day they proposed and discussed new devices. Orville thought the shifting of the upper surface backward and forward over the lower one, for longitudinal equilibrium, though successful in their kite, would not be practical for a man-carrying glider, which would start and land on the ground. He suggested that the wing surfaces be fixed one above the other, and that an elevator be placed some distance in front of the wings, instead of at the rear. In this position there would be less danger of the elevator touching the ground in starting; and if from any cause the elevator were disabled it would be discovered before the machine got into the air. Wilbur then proposed that, since curved surfaces were more efficient than flat planes, the front rudder, or elevator, should be made flexible. Then it could be bent to present a concave surface on whichever side a pressure was desired, but would be flat when moving edgewise through the air.