Elmer Ambrose Sperry (October 12, 1860 – June 16, 1930) was a prolific inventor and entrepreneur, most famous as co-inventor, with Herman Anschütz-Kaempfe of the gyrocompass.
Sperry was born at Cortland, New York, United States of America. He spent three years at the state normal school there, then a year at Cornell University in 1878 and 1879, where he became interested in dynamo electricity. He moved to Chicago, Illinois, early in 1880 and, soon after founded the Sperry Electric Company. In 1900 Sperry established an electrochemical laboratory at Washington, D.C., where he and his associate, Clifton P. Townshend, developed a process for making pure caustic soda from salt and discovered a process for recovering tin from scrap metal. Sperry experimented with diesel engines and gyroscopic compasses and stabilizers for ships and aircraft. In 1910 he started the Sperry Gyroscope Company in Brooklyn, New York; his first compass was tested that same year in USS Delaware (BB-28). His compasses and stabilizers were adopted by the United States Navy and used in both world wars. In 1918 he produced a high-intensity arc lamp which was used as a searchlight by both the Army and Navy. After setting up eight companies and taking out over 400 patents, Sperry died in Brooklyn on 12 June 1930.
His companies included: