Electric motor probably made for the physicist Luigi Magrini. It is mounted on a wooden block attached to the base. The large brass wheel is rotated by a double crank, also linked to the commutator. Two electromagnets are energized in turn, each one attracting a steel plate (armature) suspended by two rocking arms hinged to a wooden upright. A brass rod connects the system to one of the two cranks. The motion thus resembles that of steam-engine pistons. Provenance: Lorraine collections.