By placing one of the coils, A, on the magnet frame, B, and connecting
it by the wires with the galvanometer, arranged as before described,
and bringing the permanent magnet, F, suddenly against the poles of
the magnet, as shown in Fig. 11, a current will be induced in the
coil, which, in passing through the galvanometer, causes the needle to
be deflected in one direction, and when the permanent magnet is
suddenly removed from the electro-magnet, a current will be set up in
the opposite direction, which will cause a deflection of the needle of
the galvanometer in the opposite direction.