For more than a century, "Becker" and its forerunner, "Abraham-Becker," have served as the bible of electromagnetic theory for countless students. This definitive translation of the physics classic features both volumes of the original text. Volume I, on electromagnetic theory, includes an introduction to vector and tensor calculus, the electrostatic field, electric current and the field, and the theory of relativity. The second volume comprises a self-contained introduction to quantum theory that covers the classical principles of electron theory and quantum mechanics, problems involving one and several electrons, radiation theory, and the relativistic theory of the electron. Based on research by the great Harvard science historian Gerald Holton, this book clearly explains Maxwell's and Dirac's field equations and contains a profound discussion and elegant use of the Helmholtz theorem on vector fields. Problems with solutions appear throughout the text, which is illuminated by 148 illustrations.