The history of magnets and their early uses.
The magnet is one of the oldest servants of mankind and has contributed much to the advancement of civilization. In the dawn of recorded history is found legendary accounts of a crude compass used by the Chinese about 2700 B.C. which probably utilized the lodestone. The term 'magnet' is said to have been derived from Magnesia, a city in Asia Minor where many such lodestones were found. To this region is ascribed, by legend, the discovery that the lodestone would attract iron.
Throughout the history of magnets the earliest uses of magnets were as a compasses, magnets were regarded with awe and many strange properties were attributed to them. In the 13th century it was discovered that iron could be magnetized by contact with lodestone and Peter Peregrinus discovered that like magnetic poles repel each other and unlike poles attract each other. In the 15th century William Gilbert lifted the curtain of mysticism concerning magnets, evaluating the known facts concerning them. He developed the facts that the earth may be considered as one large magnet and that every magnet must have two poles.
While the compass using the magnet becomes a valuable aid to navigation and exploration, improvement in permanent magnet materials had to await the discovery of other magnetic and electric phenomena which made possible the measurement of magnetic values. Chief among these were Hans Christian Oersted's discovering in 1820 that there was a relationship between electricity and magnetism, Ampere's determination that two coils through which an electric current was passing acted like magnets, Arago's finding that iron could be magnetized if placed in a coil through which a current was passing and Faraday's discovery that electricity could be generated by changing the magnetic flux within a coil. This information made possible the development of devices for measurement of electrical and magnetic values which were required for the development of permanent magnet material. In the latter part of the 19th century improvements were made in permanent magnet steels and in the last few years great strides have been made in producing more powerful permanent magnet alloys. The development from the early lodestone to the strongest known permanent magnet material of today, Alnico V, is a remarkable achievement. As a consequence, modern civilization has a material which is utilized in many industrial and domestic applications, and gives promise of further improvements in existing devices and developments in fields as yet unexplored. The mysterious power of the primitive lodestone, enhanced by modern developments in permanent magnet alloys has become a factor having great possibilities in an era paced by the miracles of electronics.
Courtesy of the Indiana Steel Products Co., Copyright 1945