I
13
KINETIC ENERGY OF ELECTRICITY IN MOTION [1]
Connection of the galvanometer to the bridge.
Reversal of the current.
Reversal of the galvanometer.
(Repeated twenty times.) .
Reversal of the current.
Throwing the galvanometer out of circuit.
Its arrangement is shown in Fig. 1. A circular disc
revolving about a vertical axis has attached to its edge radially
FIG. 2.
FIG. 1.
twenty amalgamated copper hooks of the form shown in Fig.
2, which just dip into the mercury contained in the vessels
B and C. They are
alternately nearer to
and farther from the
axis, so that the inside
ends of the farther
ones and the outside
ends of the nearer ones
lie on the same circle
about the axis. They
reverse the current in
O
passing over the vessel
B,and the galvanometer
+
in passing over C. The
FIG. 3.
arrangement of the vessels of mercury and the method of re-
The vessel B is not exactly oppo-
relatively to it through half the
versal are shown in Fig. 3.
site to C, but is displaced