By placing the galvanometer in the circuit of the battery, as shown in
Fig. 9, and noting the deflection of the needle, it will be
ascertained that a certain amount of current is flowing. Now, by
placing in the circuit, in addition to the galvanometer, the remaining
coil of the magnet, thus introducing considerable resistance, the
current will be diminished, as shown by a smaller deflection of the
needle.