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The sixteen Century marks the beginning of the electrical understanding that will culminate with the industrial production of electrical power in the late nineteen Century. William Gilbert spent 17 years experimenting with magnetism and, to a lesser extent, electricity. For his work on magnets, Gilbert became known as the "Father of Magnetism." He discovered various methods for producing and strengthening magnets. For example, he found that when a steel rod was stroked by a natural magnet the rod itself became a magnet, and that an ion bar aligned in the magnetic field of the earth for along period of time gradually developed magnetic properties of its own. In addition, he observed that the magnetism of a piece of material was destroyed when the material was sufficiently heated.
Gilbert's De Magnete quickly became the standard work throughout Europe on electrical and magnetic phenomena. Europeans were making long voyages across oceans, and the magnetic compass was one of the few instruments that could save them from being hopelessly (and usually fatally) lost. But little was known about the lodestone (magnetic iron ore) or magnetized iron. Gilbert tested many folk tales. Does garlic destroy the magnetic effect of the compass needle? More importantly, he made the first clear distinction between magnetic and the amber effect (static electricity, as we call it). De Magnete is a comprehensive review of what was known about the nature of magnetism, and Gilbert added much knowledge through his own experiments. He likened the polarity of the magnet to the polarity of the Earth and built an entire magnetic philosophy on this analogy. In Gilbert's animistic explanation, magnetism was the soul of the Earth and a perfectly spherical lodestone, when aligned with the Earth's poles, would spin on its axis, just as the Earth spins on its axis in 24 hours. (In traditional cosmology the Earth was fixed and it was the sphere of the fixed stars, carrying the other heavens with it, that rotated in 24 hours.) Gilbert did not, however, express an opinion as to whether this rotating Earth was at the center of the universe or in orbit around the Sun.
