Excerpt from An Introduction to Electrodynamics: From the Standpoint of the Electron Theory The object of this book' is to present a logical development of electromagnetic theory founded, upon the principle of relativity. So far as the author is aware, the universal procedure has been to base the electrodynamic equations on the experimental conclusions of Coulomb, Ampère, and Faraday, even books on the principle of relativity going no farther than to show that these equations are covanant for the Lorentz-Einstein transformation. As the dependence of electromagnetism on the relativity principle is far more intimate than is suggested by this covariance, it has seemed more logical to derive the electrodynamic equations directly from this principle. The analysis necessary for the development of the theory has been much simplified by the use of Gibbs' vector notation. While it is difficult for those familiar with the many conveniences of this notation to understand why it has not come into universal use among physicists,' the belief that some readers might not be conversant with the symbols employed has led to the presentation in the Introduction of those elements of vector analysis which are made use of farther on in the text Chapter I contains a brief account of the principle of relativity. In the second chapter the retarded equations of the field of a point charge are derived from this principle, and in Chapter III the simultaneous field of a moving charge is discussed in some detail. In the next chapter the dynamical equation of the electron is obtained, and in Chapter V the general field equations are derived. Chapter VI takes up the radiation of energy from electrons, and Chapters VII and VIII contain some applications of the electromagnetic equations to material media, chosen as much for their illustration of the theory as for their fundamental importance. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.