Why does a compass point north and south?
When the magnetic needle of a compass is allowed to move freely it will
automatically place itself in line with the earth's magnetic field, one end
pointing to the magnetic North Pole while the other indicates the South.
Natural magnets, such as loadstone or pieces of iron
which have been touched by a loadstone, are to be found the world over. It was
the discovery that loadstone would always place itself so as to lie in a
magnetic north-to-south position that led to the invention of the magnet.
During the 15th Century it was
realized that the magnetic North Pole and the Geographic North Pole were not
exactly in the same place. The small angle between the two is known by seamen
as "the variation". Some experts have claimed, however, that the
Chinese were already aware of the existence of variation as early as the 11th
Century. Again, in the 15th Century, it became apparent that the earth itself
was a great magnet.
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