Magnetism

Magnetism by Ew Lee

Mention the word magnetism to one man and he thinks of a bar and iron filings; to another the word may suggest a dynamo; while a third may think of a cyclotron and the splitting of the atom. The difference would seem to depend in large part on how much one knows about this remarkable phenomenon. In this unique work, the entire subject of magnetism is presented from the earliest wondering comments on it to its meaning in space exploration.
The lodestone was known to ancient Greeks; the Chinese knew of the compass a thousand years ago; in the 16th century Gilbert described magnetic poles. Professor Lee takes us through the early experiments to the first modern accomplishments of Oersted, Ampere, and Faraday, which established the link between magnetism and electricity. We then learn of the principles behind electric motors, dynamos, transformers, permanent magnets, synchrotrons, solenoids, memory banks in computers, betatrons, magnetic supercooling, and other modern applications. It makes engrossing reading.
In developing the scientific story, the author shows us how magnetism works, with reference to such concepts and principles as lines of force; ferromagnetism; the atomic theory of matter in relation to electromagnetic properties; paramagnetism and diamagnetism; quantitative measurement of magnetic force; domains and domain boundaries; high-permeability alloys, their theoretical basis and uses; magnetic matrices used as computer-age storage devices; ferromagnetism and antiferromagnetism; the use of magnetism in modern scientific research; and problems of the earth's magnetism, including its meaning to the Wegener theory of continental drift, and solar phenomena.
The general reader will find more than 60 graphic representations such as diagrams and sketches, and 32 pages of photographic plates, to aid the exposition; while the more advanced reader is provided with the mathematical formulae behind some of the theoretical material. Students, those having a practical interest in physics, electricity and engineering, and anyone interested more than superficially in how things work will learn much here about a primary force and a sophisticated tool concerning which more than a thousand scientific papers are published annually.