Why were sailors able to use the Earths magnetic field to navigate the seas?

Answer 1

Sailors were and are able to use the Earth's magnetic field to navigate the seas because of the consistency of its orientation. The simple device known as a compass, which is used to indicate the direction of the Earth's magnetic field, contributes to navigational cues by giving an orientation of the ship through the act of comparison to the direction of the Earth's magnetic field, thus yielding useful information about the direction in which the ship sails. Unlike celestial bodies which can also be exploited to provide navigational information, the compass usually operates day or night and regardless of whether the sky is overcast. There are of course nuances in the operation of the compass, such as variation and deviation - allowances for slight local changes in geomagnetic force and differences between true north and magnetic north depending on global position (such as latitude).

Answer 2

One of the earliest uses of magnets was to use magnets for compasses on ships. Magnets were also thought to keep skin youthful, and were used in acupuncture, and reflexology.

Answer 3

Navigation. to locate magnetic North even when it was cloudy.