One of the pronounced developments of the last two or three years has been the general adoption of various starting means for setting the engine in motion without recourse to the usual form of hand crank. Some of these motor starting systems merely replace the usual hand crank with some means of turning the motor over without leaving the seat by purely mechanical connections. Others, on 1912 and 1913 models of a few cars, depend on air pressure, while the most popular and generally applied forms to 1916 model cars depend on electricity as a source of power for a small electric starting motor. Electric starting and lighting systems have been made in many forms, though the basic principles of operation are practically the same in all systems that can be grouped in several main classifications. It will not be possible to describe all in a general treatise of this nature, but if the features of the leading systems are outlined it will not be difficult for the repairman or student to become familiar with the principle of other systems which may be slightly different only in points of minor detail. Not only are the various parts of leading systems shown, but as a result of the co-operation of the leading automobile manufacturers, the author is enabled to show the actual application of the various ignition, generating and starting units to leading power plants. While a certain amount of technical exposition is unavoidable, everything has been stated as simply as possible so readers without technical knowledge can understand the principles and method of operation, as well as location of troubles in the popular systems. The illustrations have been carefully selected and all wiring diagrams are of representative systems actually in use. The reader not versed in electrical science will find that careful perusal of the chapter on "Elementary Electricity and Magnetism" will enable him to understand many of the more technical descriptions and wiring diagrams. As electricity is used for operating many accessory devices besides the lighting, ignition and motor starting units, a chapter is devoted to the unusual applications of the electric current.