What was a “rotary” engine?
Rotary engines were characterized by a stationary crankshaft around which the entire engine revolved, thereby cooling the engine and eliminating the need for a flywheel. Rotary engines, which were very expensive, were noted for their smooth operation, especially in comparison to more conventional engines used on aeroplanes during the period. The most famous series of rotary engines used during the period were those produced by Société Des Moteurs Gnôme in France. Many pioneer aeroplanes, especially Blériot XI monoplanes, were powered by Gnôme rotary engines. Indian and Gyro rotary engines, similar to the Gnôme, were built and sold in the U.S.
