A d.c. motor with a permanent magnet field in which the formerless armature winding rotates about a stationary soft iron core. The rotor inertia is then that of the windings and commutator only and the speed is sufficiently proportional to the applied voltage to permit the motor being used as an integrator.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
Centre of buoyancy
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM