AN INTRODUCTORY TREATISE ON BY GEO. D. SHEPARDSON, M.E. SECOND EDITION SIXTH IMPRESSION MCGRAW-HILL BOOK COMPANY, INC. LONDON: HILL PUBLISHING CO., LTD. HARVARD UNIVERSITY COPYRIGHT, 1901, BY AMERICAN ELECTRICIAN COMPANY AND 1908, BY THE MCGRAW PUBLISHING COMPANY NEW YORK PREFACE TO SECOND EDITION. In this edition, the opportunity has been taken to revise many sections that had become obsolete, to correct a few errors which crept into the earlier edition, and to add considerable information. Changes of greater or less magnitude have been made in over two hundred sections. The index has been amplified correspondingly. More than sixty new cuts have been added or substituted for those obsolescent. The Appendices, added in this edition, will be found to contain much information in convenient form. The writer realizes that some chapters might have been further enlarged and new ones added, without exceeding the scope of an introductory discussion. It is believed, however, that the work as now presented, illustrates the practice and beliefs of to-day. Minneapolis, September, 1908. ་་ |
