- they find true north as determined by Earth's rotation, which is different from, and navigationally more useful than, magnetic north, and
- they are unaffected by ferromagnetic materials, such as ship's steel hull, which change the magnetic field
Monday, 16 June 2014
Elmer Ambrose Sperry, Sr. (October 12, 1860 – June 16, 1930) was an American inventor and entrepreneur, most famous as co-inventor, with Herman Anschütz-Kaempfe of the gyrocompass. His compasses and stabilizers were adopted by the United States Navy and used in both world wars. He also worked closely with Japanese companies and the Japanese government and was honored after his death with a biography in his honor.
Sperry was born at Cincinnatus, New York on October 12, 1860 to Stephen Decatur Sperry and Mary Burst. He was a descendant of Richard Sperry. His mother died the next day, from complications from his birth. He spent three years at the state normal school in Cortland, New York, then a year at Cornell University in 1878 and 1879, where he became interested indynamos. 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 and discovered a process for recovering tin from scrap metal. Sperry experimented with diesel engines and gyroscopic compasses and gyroscopic stabilizers for ships and aircraft.
In 1910 he founded the Sperry Gyroscope Company in Brooklyn, New York; his first compass was tested that same year in USS Delaware (BB-28). In 1914 he won a prize from the Aero Club of France for his airplane stabilizer. He also was awarded a Franklin Institute Medal in the same year. 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.
In 1925, his son, Lawrence Burst Sperry (1892-1925), died in the North Sea in the crash of an airplane of his own design. In January 1929 he sold his Sperry Gyroscope Company to North American Aviation. The following year his wife died on March 31, in Havana, Cuba. He died at St. John's Hospital in Brooklyn, New York on June 16, 1930 from complications following the removal of gallstones six weeks earlier. He was 69 years old.
A gyrocompass is a type of non-magnetic compass which is based on a fast-spinning disc and rotation of the Earth (or another planetary body if used elsewhere in the universe) to automatically find geographical direction. Although one important component of a gyrocompass is a gyroscope, these are not the same devices; a gyrocompass is built to use the effect of gyroscopic precession, which is a distinctive aspect of the general gyroscopic effect.
Gyrocompasses are widely used fornavigation on ships, because they have two significant advantages over magnetic compasses: