PREFACE This volumc has been prepared to satisfy the demand for a systematic course of study dealing with the ignition systems used on aubomobiles, trucks, tractors, and airplanes. In preparing the text the authors have had in mind the needs of the men who have to install, adjust, and repair ignition systems in the factory and repair shop, as well as the needs of the automobile owner who desires a better understanding of the principles and construction of the modern ignition system. A few systems have becn included which are no longer manufactured but many of which are still to be found in operation. The authors wish to express their appreciation of the help and constructive criticism of Profossm Ben G. Elliott the help of Mr.Lawrence E. Blair in the preparation of many of the drawings and the cocperation of many of the manufacturers of the equipment.