The first successful rotary engine is generally attributed to F.O. Farwell in 1896, and was built by the Adams Company of Dubuque, Iowa. A three cylinder version likely powered the first rubber-tired automobile in 1899.
Because of its light weight, this five cylinder engine was selected by Emile Berliner, an inventor possibly better known in the acoustics field, to drive a helicopter's vertical shaft in a 1908 "test rig." It was reported by the New York Times on July 1, 1909 that a helicopter jointly designed by Berliner and J. Newton Williams, using two of these engines, successfully lifted a few feet off the ground in the last week of June 1909 with Williams aboard.
During this same period, Berliner formed the Gyro Motor Company to pursue development of the rotary engine in aviation, but the French Gnome engine was much more successful in bringing the rotary to a broad aviation market.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.