This is a tapered nozzle used as a propellant flow regulator by U.S. rocket pioneer Robert H. Goddard in a test in June 1926, about three months after he had made his historic flight of the world's first liquid propellant rocket on 16 March 1926 . Its purpose was to smooth pulses in the propellant flow and thereby regulate the pressure for constant output pressure in the operation of a rocket motor.
Friction still caused difficulty and he therefore tried other flow regulators. This regulator was therefore experimental and was not used in flight rockets. It was constructed and tested while Goddard was at Worcester, Massachusetts. This object was donated to the Smithsonian in 1959 by Esther C. Goddard.
Gift of Mrs. Robert H. Goddard