Excerpt from Electrical Illuminating Engineering This book had its origin in a set of notes compiled and developed by the author for use in his classes. At that time there was no thought of publishing the material and no record was made of the sources of information. However, the work of Professor Wilbur M. Stine on Photometrical Measurements was consulted freely and in that depart ment of the subject will be found a valuable reference. Much of the material was obtained from the Transactions of the American Institute of Electrical Engineers, the Proceedings of the National Electric Light Association, and the Transactions of the Illuminating Engineering Society, as well as from the I lluminating Engineer, the Electrical World, the Electrical A ge, the Electrical Review, Science Abstracts, and other technical periodicals. The absence of a satisfactory text in Illuminating Engineering and the hope that a book of this nature might be of service to the profession prompted the development of the work to its present condition. 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.