This is an OCR edition without illustrations or index. It may have numerous typos or missing text. However, purchasers can download a free scanned copy of the original rare book from GeneralBooksClub.com. You can also preview excerpts from the book there. Purchasers are also entitled to a free trial membership in the General Books Club where they can select from more than a million books without charge. Original Published by: J. Wiley & Sons in 1915 in 70 pages; Subjects: Electric machinery; Electric engineering; Electrical engineering; History / General; Technology & Engineering / Electrical; Technology & Engineering / Electronics / General; Technology / Engineering / Electrical;