American rocket pioneer Robert Goddard (1882-1945) used this device between 1924 and 1928 in his experiments to determine the feasibility of ion propulsion for space travel. Ion engines, in which electrically charged particles of atoms are discharged, produce extremely high exhaust velocities. Experiments in space with ion propulsion first took place in 1964.
Russell B. Hastings, one of Goddard's graduate students at the time, described this artifact in 1964 as an "ion apparatus probably used by [Louis M.] Sleeper [another of Goddard's graduate students] or somebody subsequent to Mr. Hastings…. The collecting screen is smaller, closer to the electrode, and obviously connects to an extended device, such as an electrometer." Mrs. Goddard gave this artifact to the Smithsonian in 1965 as part of a set of laboratory glassware from her husband's pioneering ion-propulsion experiments.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.