M. Kammerer of Belgium effects this by an addition to any clock
whereby it is brought into contact with the two poles of a galvanic
battery, the wires from which communicate with a drum moved by the
clockwork; and every fifteen seconds the current is changed, the
positive and the negative being transmitted alternately. A wire
is continued from the drum to the electric clock, the movement of
which, through the plate-glass dial, is seen to be two pairs of small
straight electro-magnets, each pair having their ends opposite to the
other pair, with about half an inch space between. Within this space
there hangs a vertical steel bar, suspended from a spindle at the
top. The rod has two slight projections on each side parallel to the
ends of the wire-coiled magnets. When the electric current comes on
the wire from the positive end of the battery (through the drum of
the regulator-clock) the positive magnets attract the bar to it, the
distance being perhaps the sixteenth of an inch. When, at the end of
fifteen seconds, the negative pole operates, repulsion takes effect,
and the bar moves to the opposite side. This oscillating bar gives
motion to a wheel which turns the minute and hour hands.
M. Kammerer states, that if the galvanic battery be attached to any
particular standard clock, any number of clocks, wherever placed, in a
city or kingdom, and communicating with this by a wire, will indicate
precisely the same time. Such is the precision, that the sounds
of three clocks thus beating simultaneously have been mistaken as
proceeding from one clock.