The telegraph manual: a complete history and description of the semaphoric, electric and magnetic telegraphs of Europe, Asia, Africa, and America, ancient and modern.

INDUCED MAGNETISM. 11
tact with the bar is south, and the line of induction extends
to the points. If nails be suspended from the points the polarity
of the respective pieces will be as represented in the figure.
If the north pole be placed on the middle of the bar of iron,
as seen in figure 13, the part of the horizontal bar becomes a
south pole, and the respective ends become north. The bar
N N becomes magnetically two pieces of iron, each with its
south pole terminating at the bar s N. If pieces of iron wire
of equal lengths be suspended from a magnetic pole, they will
not hang parallel. The lower ends will diverge from each other
in consequence of their having the same polarity, as seen by
figure 13.
If a bar magnet be broken into two pieces the polarity of
each piece will at once be.
Fig. 14.
formed as seen by figure
14. These halves may be is.../
broken with the same result, each section having a full charge of the magnetic influence.
The magnetic needle is a very slender magnet mounted on
a pivot, as seen in figure 15, or it may be otherwise suspended.
Fig. 15.
Fig. 16.
Fig. 17.
|j~~~~~~~~~~ NN|i.g_,,__,.,,i5^-~is~-^