A PRACTICAL EXPOSITION OF THE ART FOR THE USE OF ENGINEERS, STUDENTS, AND OTHERS INTERESTED IN FRANCIS B. CROCKER, E.M., PH.D. PROFESSOR OF ELECTRICAL ENGINEERING IN COLUMBIA UNIVERSITY, NEW YORK PREFACE. ELECTRIC LIGHTING having now become one of the most important branches of applied science, there is a demand for information on the subject. This demand is by no means confined to electrical engineers, but applies also to mechanical, mining, and other engineers, architects, fire underwriters, students in colleges and technical schools, lawyers and business men who may be called upon to consider questions relating to electric lighting. But the development of this art has been so very rapid, and so many changes and improvements were continually being made, that heretofore any attempt at a complete treatise on the subject would become out of date while it was being printed. There are already good elementary works on electric lighting; and in the case of special branches, such as the dynamo, transformer, electrical distribution, etc., we have several excellent books; but none of these cover electric lighting as a whole, or what might be called electric-light engineering. The author believes that the time has now arrived, however, when electric lighting has reached a sufficiently perfected and established state to allow of its being treated in a fairly satisfactory and permanent manner. The apparatus and methods now employed are almost as well standardized as in other arts. The dynamo, which is the most important element, is one of the most perfect machines in existence. Arc and incandescent lamps, overhead and underground wires, transformers, and almost all the other parts of electriclighting plants, have also become sufficiently stereotyped. In fact, it is remarkable that of all the important features of an electriclighting system, the steam-engine is the one which is now being modified to the greatest extent, although it is, of course, much older than the others. The plan adopted in this book is to follow the usual sequence |