RADIAL ROTARY ENGINE
Hargrave constructed 36 engines of great variety in his quest to provide power for manned flight, commencing in 1888 with a compressed air, single cylinder motor driving two flapper wings.
One of Lawrence Hargrave’s finest inventions was the radial rotary engine of 20 February 1889, compact, smooth running, with a then phenomenal power/ weight ratio, and providing efficient cooling of the engine by the air in which it revolved around its axis. This engine was ingenious in that it rotated the cylinders around a central shaft, and drove a propeller, and not flapping wings. It was to become the major aircraft engine type for 50 years. Lawrence designed and built nine radial or radial rotary engines. As always his work was freely disseminated and the idea would be taken up by others into commercial production in the next century. His propellers were inefficient, and he returned to flapping wings for a time.
Diagram and Reconstruction of the radial rotary engine of 1889, the first of the major contributions of Hargrave to the future aeroplane.