In ancient times, the smart Greeks and Chinese people found that there was one kinds of natural stone which had the magnetism and then they called such kind of stone as magnet. As is known to all, such stone can absorb a small piece of sheet iron, which just likes the magic show. At the same time, after the swing at random, they always point in the same direction. Based on such feature, in the early time, sailors invented the earliest magnetic compass to discern the direction on the sea used such stone as raw material.
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