Elmer Sperry
DOI: 10.1063/PT.5.031327
Today is the birthday of Elmer Sperry, coinventor of the gyrocompass, who was born in Cortland, New York in 1860. By age 20 he had founded the Sperry Electric Company and opened a factory in Chicago for manufacturing dynamos and arc lamps. Sperry took out more than 400 patents during his life, but his most important one was in 1908 for the gyrocompass. For centuries sailors had relied on magnetic compasses for navigation. The gyrocompass relies not on Earth’s magnetic field but its rotation; the instrument is not magnetic, and it points to true north by means of a rapidly spinning wheel mounted on a gimbal. The US Navy began using Sperry’s gyrocompasses in 1911. They were used in both world wars and helped guide ships, airplanes, and torpedoes.
Date in History: 12 October 1860
