Publisher's Synopsis
"The story of magnetism begins with a mineral called magnetite (Fe3O4), known to attract iron as early as 2500 years ago. Later, it was found that a properly shaped piece of magnetite floating on water would turn until it pointed approximately north and south. The first truly scientific study of magnetism was On the Magnet, published in 1600 by William Gilbert. The first electromagnet was made in 1825, following the discovery made in 1820 that an electric current produces a magnetic field. Research on magnetic materials can be said to date from the invention of the electromagnet, which made available much more powerful fields than those produced by lodestones, or magnets made from them"--.
