the compass

Icebergs were not the only difficulty Henry Hudson
had to contend with while sailing  in the Arctic Seas.
A big one was the compass. This all-important
instrument was based on the that magnetized sliver
of iron will always point toward magnetic north.
     The first compass was used in the 12th century.
It consisted of magnatized icon attached to a wood
splinter floating in a bowl of water. By the 16th century
a magnetized  needle was suspended on a pin above
a card marked with the four directions- - east, west,
north and south. The card was enclosed in a bowl that was
held in place by swivels so the compass would remain level
on a tossing ship.
     Explorers eventually discovered that there is a variation
between magnetic north and true north. For Hudson, was
more severe since the compass variation increases as one
goes farther north.
Today satelite navigation helps to solve the problem,
EXPLORERS WHO GOT LOST
Published by Tom Doherty Associates Inc.
New York
ISBN 0-812-52038-6