Page 582 Advertisements Column 2

New Zealand Graphic, Volume XVII, Issue XVIII, 31 October 1896, Page 582

The reason why the needle points in a northerly direction is because the earth in itself is a magnet, attracting the magnetic needle as the ordinary magnets do, the earth being also a magnet as the result of certain cosmical facts, much affected by the action of the sun. These laws have periodicities, all of which have not as yet been determined. A condensed explanation is accepted in regard to the needle pointing to the northward and southward is that the magnetic poles of the earth do not coincide with the geographical poles — that is, the axis of rotation makes an angle of about twenty-three degrees with a line joining the former, and hence the needle does not everywhere point to the astronomical north, and is constantly variable within certain limits. The action of the earth upon a magnetic needle at its surface is of about the same force as that of a hard steel magnet forty inches long and strongly magnetized at a distance of one foot. No ultimate reason can be given of the fact in nature that the needle points to the northward and southward.