Abstract: A gyroscopic instrument which may be a compass or a turn-indicator or an artificial horizon includes a gyroscope rotor mounted in a frame for rotation and for universal pivotal motion and provided with a co-axial drum-shaped sleeve of a non-magnetic and electrically conductive material and an annular magnet having a substantially cylindrical air gap and being radially polarized to produce a radial magnetic field in said gap. This magnet is so mounted on the frame as to locate the rotor sleeve within the air gap with a radial clearance affording the rotor pivotal movability relative to the magnet.