makers make no provision for a self-starting motor, various forms of simple starters by which the motor may be cranked from the seat have been offered. Two of these are shown at the top of Fig. 352. That at A consists of a rachet clutch which is attached to the starting end of the crankshaft and which is operated by means of chain connection with the smaller pulley of a two diameter pulley wheel. The larger wheel carries a wire cable which is attached to a straight rod running through the dash board and terminating in a handle convenient to the driver's hand. A pull on the spade type handle provided at the end of the rod will move the pulley wheel and produce a corresponding movement of the starting rachet which turns the engine crankshaft over in the same way as the hand crank does. A modification of the device shown at A is outlined at B. This works on the same principle, except that an odd-shaped member is used to turn over the engine crankshaft. These devices are in no sense of the word "self-starters,” but on light motor cars they provide an effective substitute in that the engine may be turned over without undue exertion and without leaving the seat. This is an advantage of some moment when the engine stalls in traffic, or under conditions where it would be inconvenient to get out of the car. Q. Do all mechanical starters attach to the front of the engine crankshaft? A. Two types of mechanical starters known as the Wilkinson are shown at the bottom of the illustration, Fig. 352. The one at D is operated by pulling a handle on the dash, the one at C by a pedal designed for foot actuation. The mechanism is such that the flywheel is pushed around by a lever which will engage with either a stud or a shoulder on the flywheel. The type at the left uses the studded flywheel, there being four of these marked “S.” When the arm C is moved by depressing a pedal, the finger A contacts with one of the stubs and turns the flywheel. Return engagement is produced by the large spring shown. In order to minimize liability of injury from backfire, the Wilkinson device. is constructed so that the pawl D rises on the cam which bears against the collar E, and thus throws the finger out of engage ment with the stud. One thrust of the pedal will turn the flywheel of a four-cylinder engine sufficiently to cause one cylinder to fire should ignition and carburetion systems be functioning properly. The type at D is just as simple, but is Fig. 352.-Showing Construction of Mechanical Devices for Starting Gasoline Engine from the Operator's Seat. modified somewhat in its construction. In this a hand lever is used to rotate the flywheel, and instead of using studs on the flywheel rim, four shoulders in the interior periphery do the work. These shoulders may be cast with the wheel, or in some cars it is possible to have them cut in the flywheel. The operation is the same as that of the type previously described as the movement of the cable causes the finger to engage with one of the shoulders, and thus turn the flywheel. Q. How do electric starters work and how are they classified? A. Electric lighting, cranking and ignition systems for motor cars are of such recent development that it is not possible to describe all systems used for this purpose. Not only do the individual systems vary in detail, but the components of the same system are often of different construction when used on cars of different makes. The standard equipment must include three important functions, namely, the generator which is driven by the engine end which produces electric current to keep a storage battery charged, and the starting motor which is in mechanical connection with the engine and in electrical connection with the storage battery when it is desired to turn the engine over for starting. If the motor and generator are combined in one instrument the starting system is known as a one unit type. If the motor is one appliance and the generator another, the system is said to be a two unit system. Each of these has advantages, and both forms have demonstrated that they are thoroughly practical. Q. Name other parts of electric starting system. A. In addition to the three main items enumerated, various accessories, such as switches, ammeters, connectors, wiring, protective circuit breakers, automatic current regulators, etc., are necessary for the convenient distribution and control of the electric current. Q. Describe arrangement of parts of "one unit" system. A. The elements of a one unit system are shown in diagram form at the bottom of Fig. 353. It will be observed that the armature carries two commutators, one of which is used when the armature is driven by the engine, and when the device serves as a current generator, the other being employed when the operating conditions are reversed and the electrical machine is acting as a motor to turn over the engine crankshaft. When the device is driven as a generator the small sliding pinion on the short end |