... showing that an electric current is again flowing through the coiled wire on the armature, but reversed in direction. He notices, too, that these effects take place only while changes are going on in the strength of the magnetism in the armature, or when magnetic flux is passing through the coils; for, the galvanometer needle comes to rest, and remains at rest as long as the contact between the armature and ... — Beacon Lights of History, Volume XIV • John Lord