Electrical machinery a study of principles of design, construction and operation This book, "Electrical machinery a study of principles of design, construction and operation", by Ottomar Henry Henschel, is a replication of a book originally published before 1920. It has been restored by human beings, page by page, so that you may enjoy it in a form as close to the original as possible. This book was created using print-on-demand technology. Thank you for supporting classic literature.