Torsion Gears And Rear Vertical Tail - Thursday, September 18, 1902
The History: In his person diary, Orville reported that they had finished the front rudder and end torsional gears. The brothers began work on the rear vertical tail.
The word "torsion" means to exert a force which twists a body. In particular, torsion refers to twisting a body so that one end or part turns while the other is fixed (stays in place) or turned in the opposite direction.
The torsion gear was used to twist the glider's wings. The Wrights referred to this "twisting" as wing warping. The gear twisted the surfaces of the wings in opposite directions. By doing this, one wing would be higher than the other and allowed the pilot to turn the glider.