It is believed this artifact is a 37 kW (50 hp) Curtiss E-4, operated at a lower than normal rotational speed. It was the first of Curtiss water-cooled engines, and the first of two engines to power the U.S. Army Signal Corps Dirigible No. 1, the first U.S. military airship. The engine drove a tubular steel shaft about 6.7 m (22 ft) long on which was mounted a wooden propeller designed by Lt. Thomas E. Selfridge.
In 1908, the Signal Corps awarded Thomas Baldwin a contract for the construction of an airship not to exceed 36.6 m (120 ft), to be completely maneuverable, and to obtain a speed of 32 km/hr (20 mph). Baldwin piloted the airship, and Glenn Curtiss was the engineer. In the official speed run, the Baldwin airship reached 31.38 km/hr (19.61 mph).
After service at Fort Meyer and Omaha, this engine was replaced by another Curtiss Model E-4 engine, also in the museum’s collection.