an improved solenoid for providing linear actuation . the outer polepiece of the solenoid is provided with a plurality of radially - dispersed labyrinthine passageways in communication between the exterior of the solenoid and an interior region including the armature and the interior of the windings . the polepiece is further provided with at least one passageway in communication between the exterior of the solenoid and an outer periphery of the windings within the housing . the two sets of passageways impede particles and droplets of moisture from entering the solenoid , while simultaneously permitting moisture such as condensation within the solenoid to evaporate and escape .