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.
According to a 1964 note written by Russell B. Hastings, one of Goddard's graduate students at the time of the ion experiments, "the tube looks like an early attempt to either singly deflect electrons by a magnetic field or possibly to measure the ratio of charge to mass.... If so this might be a prize piece." 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.