The car is started by opening the gasoline supply cock, closing the ignition switch, and pushing the car along the track until the first explosion occurs. The speed is controlled in the usual manner by means of the spark advance and throttle. As the motor is of the two stroke cycle type, it may be reversed by simply changing the position of the timer without the use of the gears. The speed is the same in either direction. By the use of three cylinders, three impulses are obtained per revolution which gives a distribution of power equal to that of the ordinary six cylinder, four stroke cycle automobile motor. [Illustration: Fig. 56. Two Stroke Cycle Fairbanks Motor for Driving Railway Section Cars. ] For larger cars built for carrying large gangs of men, a three cylinder motor is used which drives through a clutch and gears, similar to that used on automobiles. It is located near the center of the axle and is supported on a frame that is independent of the car proper. This motor unit is easily removed from the car for inspection with all of the parts intact. A universal coupling is provided on the motor shaft to prevent strains due to changes in the alignment from being thrown into the motor. The motor of this car is started with a crank, and may be left standing with the motor running. As with the two cylinder car, the engine is reversible, and is lubricated by mixing the lubricating oil with the gasoline. (58) Rotating Cylinder Two Stroke Cycle Motor. An unusual type of two stroke cycle engine is that designed by M. Farcot for aeronautic work. It is of the rotating cylinder type in which the cylinders rotate about a stationary crankshaft, and unlike all previous two stroke motors, whether of the revolving or stationary cylinder type, no initial compression is performed either in the crank-case or otherwise. [Illustration: Fig. 63. Farcot Rotary Two Stroke Motor. ] Undoubtedly the two-cycle rotating multi-cylinder engine has a future when some of the particularly difficult designing problems involved in its production have been successfully tackled. Crank case compression has had its devotees, but so far it has entailed the use of a low compression, owing largely to the difficulties involved in lubricating the bearings and maintaining gas-tight joints, besides other defects. Some of these barriers appear to have been surmounted in this design.