Excerpt from Advanced Theory of Electricity and Magnetism: A Textbook for Colleges and Technical Schools To make the study of theoretical physics something besides a 5 purely formal mathematical exercise, it is necessary to keep physical things always clearly and vividly in mind. It is comparatively easy to do this in the study of applied science, but it is extremely difficult to do it in the study of many of the unfamiliar topics which are discussed in this book. The character of the treatment in this book has been determined throughout by the desire to keep the student's mind jammed up tight against physical things The chapter on potential, for example, is kept within severely concrete limits, and the student who wishes to get an insight into the elementary mathematical theory of potential should read chapter IX of Franklin, MacNutt and Charles' Calculus published by the authors. South Bethlehem, Pa., 1913. The authors desire to express their appreciation of the great assistance which Professor R. L. Charles has rendered in the preparation of this book. 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.