A north-seeking form of gyroscope used as a directional reference in navigation. The first practical gyrocompasses were developed by H. Anschütz (Germany) in 1908, E. A. Sperry (United States) in 1911, and S. G. Brown (England) in 1916. Modern gyrocompasses are so reliable and so much more accurate than magnetic compasses that they are now used as the prime navigational instrument on nearly every ship and on major aircraft and missiles.