GYROSCOPE

Symmetrical mass, usually a wheel, mounted so that it can spin about an axis in any direction. Once a gyroscope starts to spin, it will resist changes in the orientation of its spin axis. Large gyroscopes are used in ship stabilizers to counteract rolling. The gyroscope is the nucleus of most automatic steering systems, such as those used in airplanes, missiles, and torpedoes. It is also used in the gyrocompass, a directional instrument used on ships. .