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. Because of that and potential long duration of operation, ion engines are ideal for deep space propulsion. However, they produce very low thrust and must be placed in space by conventional rocket boosters. Experiments in space with ion propulsion first took place in 1964.
Russell B. Hastings, one of Goddard's graduate students connected to his ion work, has identified this object in 1964 as "very likely a concentric screen device for detecting both plus and minus ion emissions." Mrs. Goddard gave it to the Smithsonian in 1965. It was later broken and partly lost as the Hastings states it was originally "two tubes with sealer and electrodes."
Gift of Mrs. Robert Goddard