ABSTRACT
William Gilbert's Latin work of 1600, De magnete was a remarkable and widely read work of natural philosophy that the likes of Kepler and Galileo read and took very seriously. Gilbert held that the earth revolves on its axis, thereby shifting the poles from their natural home in the heavens to the surface of the earth, where they defined that terrestrial axis. It is a matter of conjecture as to whether Gilbert also subscribed to the Copernican view that this revolving earth also orbited the sun, stationary at the centre. The association between magnetism and navigation, represented by the magnetic compass, was an important part of Gilbert's book, which drew on much practical lore from seamen. The pointing of the iron touched by a loadstone are made known to navigators even under an overcast sky and in the darkest night; which before the discovery of this wonderful virtue was clearly impossible.
