The actual construction of the engine is better shown in Fig. 16, in which A A are the cylinders, B is the steam chest and G G are the valve rods. The piston rods connect with the crossheads C. The connecting rods D transmit motion from the latter to the cranks E, and thus rotate the shaft S. The link motions, by means of which the direction of rotation is reversed, are at I I, and are operated by the lever G, which is mounted upon the shaft F F. This shaft is directly connected with the starting lever. The boiler feed pump is located at M. The motion of the engine is transmitted to the rear axle of the carriage by means of a chain that runs over the sprocket wheel L located between the eccentrics K K. In Fig. 15, this wheel is located at D, and the chain F connects it with the axle sprocket E. [Illustration: FIG. 17. AMERICAN STEAM AUTOMOBILE OF 1900.] Fig. 17 shows another American steam carriage. In this vehicle the running gear is a complete truck, upon which the carriage body is supported. The appearance of the truck with the body removed is shown in Fig. 18. The boiler is of the tubular type and the double cylinder engine is secured to its side. In this particular the construction differs from that of the previously described carriage, for in that the engine is attached to the cross-framing of the body of the vehicle. Although the general appearance of the mechanism of these two carriages is very similar, there are many differences in the details of their construction. In both, vertical tubular boilers are used, and the steam is generated by the use of gasoline, which is burned in the vaporized state in specially constructed burners. The engine in both cases is of the vertical double cylinder type, and motion is transmitted to the hind axle by means of sprocket wheels and a chain; but here the similarity ends; the minor details, which it is not necessary to refer to in this connection, are with few exceptions very different. [Illustration: FIG. 18.]