This artifact was donated by Paul E. Garber, the museum's first curator. He associated the propeller with a World War I era Nieuport N-6 aircraft and Gnome Monosoupape, a rotary engine having one mechanically operated exhaust valve. Although no reference is provided and there are no markings on the artifact to confirm this, museum records and the distinctive “diamond” shape indicate the propeller was manufactured by Lang, an early leading British manufacturer.
Arthur Alexander Dashwood Lang took out a patent in 1909 for “an improved formation of the blades of propellers for use on airships and aircraft where greater efficiency is secured.” The curvature of blades having a “convex side and a flat side” was described in the patent application. Lang Propeller Ltd. was a principal supplier to Sopwith, and was bought out by that well known aircraft builder in 1917.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.