ABSTRACT
A magnetic oxide of iron occurs in a natural state in various parts of the world, and numerous references to the properties of lodestones are to be found in Greek and Latin literature. From these notices it is evident that the ancients were familiar with the lodestone’s power of attracting or repelling pieces of iron, and of communicating to them properties similar to its own. The modern development of the sciences of magnetism and electricity owes very much to the work of William Gilbert, the greatest English experimentalist of his time. The first important advance upon Gilbert’s work was the discovery that the variation of the compass at any place generally changes in course of time. Even in the sixteenth century the necessity for taking account of such changes seems to have been recognized by the Flemish compass-makers.
