The patent illustrates a non-powered flying machine—namely, the 1902 glider. The patent's importance lies in its claim of a new and useful method of "controlling" a flying machine, powered or not. The technique of wing-warping is described, but the patent explicitly states that other methods instead of wing-warping could be used for adjusting the outer portions of a machine's wings to different angles on the right and left sides to achieve lateral (roll) control. The concept of varying the angle presented to the air near the wingtips, by any suitable method, is central to the patent. The patent also describes the steerable rear vertical rudder and its innovative use in combination with wing-warping, enabling the airplane to make a "coordinated turn", a technique that prevents hazardous "adverse yaw", the problem Wilbur had when trying to turn the 1901 glider. Finally, the patent describes the forward elevator, used for ascending and descending.