1761
Illinois Legacy Collection, Illinois State Museum
Gift of Mrs. Robert Gillespie, 1972.028.746876
James and Ralph Clews Pottery
Staffordshire, England
1815-1834
Photoelectric relay made at Yerkes Observatory, Williams Bay, Wisconsin, with the cooperation of the General Electric Co., and photoelectric cells by R. J. Cashman and W. S. Huxford, 1933. Courtesy of the Adler Planetarium.