Does a compass sometimes point downward along with pointing north?

For hundreds of years, navigators using compasses noticed that on occasion, the compass pointer would try to point downward in addition to pointing north. This phenomenon, which went unexplained for several hundred years, was observed by compass maker Robert Norman. He found when flying over the poles one end of the compass would point downward; he understood that the problem was that the pointer was attracted to the pole under the plane. By making the compass rotate in the vertical direction he made the first dip needle.


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