geographical poles, hence the declination of the needle, that is
to say its angle of divergence from the true meridian or north and
south line, is gradually changing. The north magnetic pole of the
earth was actually discovered by Sir John Ross north of British
America, on the coast of Boothia (latitude 70 degrees 5' N,
longitude 96 degrees 46' W), where, as foreseen, the needle
entirely lost its directive property and stood upright, or, so to
speak, on its head. The south magnetic pole lies in the Prince
Albert range of Victona Land, and was almost reached by Sir James
Clark Ross.

The magnetism of the earth is such as might be produced by a
powerful magnet inside, but its origin is unknown, although there
is reason to believe that masses of lodestone or magnetic iron
exist in the crust. Coulomb found that not only iron, but all
substances are more or less magnetic, and Faraday showed in 1845
that while some are attracted by a magnet others are repelled. The
former he called paramagnetic and the latter diamagnetic bodies.

The following is a list of these.--

Paramagnetic Diamagnetic
Iron Bismuth
Nickel Phosphorus
Cobalt Antimony
Aluminium Zinc
Manganese Mercury
Chromium Lead
Cerium Silver
Titanium Copper