more extended mathematical course. To meet the demands of these various classes has been the object of the writer in the preparation of this volume.
As mathematics is simply an abbreviated form of language, mathematical reasoning, where required, has been reduced, so far as possible, to ordinary language, intelligible to unmathematical readers; thus reducing the amount of mathematical formulae required to a very few simple expressions, not beyond the capacity of persons familiar with arithmetic.
Each chapter is intended to be a complete treatise on the subject to which it relates, and the whole thirteen to embrace all the essential facts pertaining to that form of electricity which manifests itself in currents, as distinct from the form known as static, which has been similarly treated in the author's "Elements of Static Electricity." The publication of the latter book in a separate volume, and the elimination of mathematical formulae from the present book, have left room for a much fuller treatment of the physical principles of electric science in this, its most practical form, than would otherwise be possible in a volume of this size.
This book is not intended as an exposition of the writer's own peculiar views, but of the well established principles of electricity and magnetism, as held by the leading electricians of the world. The writer has collected facts from every available source; examining carefully the views of various eminent writers on each point, and giving the net result of such examination in his own language; inspecting the construction and practical operation of electric apparatus and machinery, and consulting practical, electric experts, familiar with such construction and operation.
The chronological order of electric development has been followed, so far as possible, as it is not only in
