Date: ca. 1924-1928
Country of Origin: United States of America
3-D Test: 15.2 x 2.5 x 1cm (6 x 1 x 3/8 in.)
Other (Wire): 30.5cm (12 in.)
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 who, as a graduate student at Clark University, helped Goddard make these types of tubes, described this artifact in 1964 as a "very early experiment[,] probably collection of electrons by a concentric cylindrical collecting electrode." 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.
Gift of Mrs. Robert Goddard