Abstract: A conveyor comprising a trolley movable along a track and having at least one elongate member of ferromagnetic material which is settable in a position selected according to a code to convey information concerning the destination of the trolley. At a reading station on the track, there is a row of magnetically-operated switches with magnetic shields between them. With each switch there is associated a pair of magnets disposed on opposite sides of the switch with one magnet of the pair between the switch and the path followed by the elongate member through the reading station. When aligned with the magnets of a switch, the elongate member operates the switch as the member passes through the reading station.