My good friend Albert Harvey of Nottingham, NH invented a true rotory engine with no reciprocating parts! This prototype has some leakage so it does not run as well as it could (also was a cold day in the shop). This engine design can conceivably run on all fuels including hydrogen given its cross rotor system--one way valve system. Shown here running on propane. A true reduction to practice of a novel engine design with huge potential in an energy constrained world!