VARIATION OF THE COMPASS*. FHE variation of the Compass, is the deviation of the magnetic or mariner’s needle from the meridian or true north and south line. On the continent it is called the clination of the magnetic needle; and this is a better tern* for reasons which will afterwards appear. Our readers know, that the needle of a mariner’s cornpa 55 is a small magnet, exactly poised on its middle, and turning freely in a horizontal direction on a sharp point, so that it always arranges itself in the plane of the magnetic action- About the time that the polarity of the magnet was fi rS * ; observed in Europe, whether originally, or as imported fr° ul China, the magnetic direction, both in Europe and in China> was nearly in the plane of the meridian. It was therefore an inestimable present to the mariner, giving him a sure direc tion in his course through the pathless ocean. But by time that the European navigators had engaged in their a ' venturous voyages to far distant shores, the deviation of th e • It is necessary to remind the reader, that the following article on the ^ riation of the Compass, was published a considerable time before the *r ' on Magnetism.—Ed.