Title page from 'De magnete', 1628.
© Science Museum / Science & Society Picture Library
Engraving from 'De magnete' (On the magnet) by William Gilbert (1540-1603), published in Stettin, Poland, in 1628. Gilbert's experiments in magnetism, and his use of such terms as 'electric force', 'electric attraction', and 'magnetic pole', are the basis of the growth of the field of electricity. He discused the earth's magnetism by making a model - a spherical piece of loadstone called a terrella (little earth). This engraved title page, added for this unauthorised second edition, shows loadstones, compases and a terrella. A philosopher faces a sailor, each holding the tools of their trades. A ship is shown in a vignette, apparently sailing away from a floating bowl compas with a terrella at the centre.