FIGURE 15.-Sectional view of Figure 14, showing location of engine, boiler and other details.

The boiler is a very compact form of the upright type, such as is used in fire engines. It is about fourteen inches in diameter and twenty inches high. To increase its strength, it is surrounded with two layers of piano wire. The engine is of the locomotive type, consisting of two cylinders, the pistons of which are connected with cranks on the end of the shaft, these cranks being set at right angles, so as to prevent catching the engine on the dead center. The direction of rotation is reversed by means of the ordinary link motion. The fuel used is gasoline, which is carried in the cylindrical tank located under the front of the carriage. The gasoline is vaporized and then, mixed with a proper proportion of air, passes to a burner placed under the boiler. The amount of steam generated is regulated by the amount of gasoline supplied to the burner, and this supply in turn is regulated by the pressure of the steam, so that the action is entirely automatic. The cylinder H is a reservoir of compressed air, connected with tank I, so that the gasoline is under pressure, and therefore is forced through the pipe to the burner under the boiler. Between the burner and the tank there is a valve controlled by the steam pressure, being opened when the pressure is low and closed when it is high. When the pressure reaches a certain point the valve is closed entirely, so that even if the carriage is running very slowly, it is not possible to run the pressure above the fixed limit. The exhaust passes from the engine cylinders into a muffler, from which it escapes into the pipe K. This pipe projects downward into an opening through the center of the water tank, and the draught produced thereby draws the gases of combustion through from the top of the boiler to the under side of the carriage body, where they escape into the atmosphere.

FIGURE 15A.-Plan of Steam Carriage shown in Figures 14 and 15.

Directly in front of the exhaust muffler is seen the water gauge, which is in such a position as to be outside of the carriage body, as shown in Fig. 14. A mirror is placed at the front of the vehicle, and by looking into this the water gauge can be seen. Fig. 14 also shows clearly the position of the operating levers at the side of the carriage.

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.

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.

FIGURE 16.-Engine of Carriage Shown in Figure 14.

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at a red heat by means of a flame impinging against its outer surface. When the explosive mixture is compressed it rises in the interior of the hot tube, and when it reaches the portion that is hot enough to produce combustion an explosion takes place. By many engineers this arrangement is regarded as superior to the electric spark on account of its simplicity.

Gasoline motors are made with one, two or more cylinders, but in each cylinder the action that takes place is that described above. The actual construction of a motor is not so simple as might be assumed from the appearance of Fig. 1; many details are required which are not here shown. A more perfect idea of the actual construction of a gasoline motor can be had from Fig. 2, which is a working drawing of a recent European invention. In this design it will be noticed that the cylinder is cooled by radiation into the surrounding air, the exterior surface being increased by numerous circular ribs and also by extending a hollow trunk from the upper side of the piston, so as not only to increase the radiating surface, but also to allow the hot air to escape from the champer T in which the crank discs revolve. In this drawing E is the explosion chamber, corresponding to Q in Fig. 1, and the valve s is the counterpart of f, while s' corresponds to the valve h. The upper pipe t is the pipe e of Fig. 1 and the lower pipe t' is the piper of the same figure. Although the crank discs, connecting rods and other details are different in shape, it will readily be seen that their relation to each other is the same.

Since a gasoline motor cannot start of its own accord, it is necessary in vehicles in which they are used so to arrange the driving gear that the moter may be kept in motion all the time and always in the same direction, hence, to reverse the direction of the carriage, reversing mechanism, independent of the motor, must be provided. The most simple mechanism for a gasoline vehicle employing spur gearing exclusively is shown in diagrammatic form in Fig. 3. In this figure A represents the cylinder of the motor, B the crank disc chamber and M the vaporizing receptacle, which is generally called the carburator. The pinion C, on the end of the motor shaft, meshes into a gear D which is mounted upon a sleeve E which revolves freely round shaft G. This sleeve has its ends formed so as to engage with the gears mounted upon shaft G, and by means of a lever, which is not shown, but which works in groove a, the clutch either s or 88 can be thrown into engagement with its corresponding gear. If 8 is thrown into gear, as shown in the drawing, the wheel F will turn H and the pinion I will rotate the gear J which is mounted upon the axle of the carriage. If the clutch ss is thrown into engagement, the gear G will turn K and this wheel will turn 1; but, as can be clearly seen, the direction in which I will revolve will be opposite to its motion when driven through F and H, therefore, if when F drives the carriage runs forward, when G drives it will run backward, and when E is moved to the central position, so that neither & nor ss engages with their respective gears, the vehicle will stand still, but the motor will continue to revolve.

FIGURE 2.-Petroleum spirit motor.

B

FIGURE 3.-Reversing mechanism.

This diagrammatic arrangement is more simple than the gearing actually used and is not as complete in action as many of the devices, as it only provides means whereby the direction of rotation of the axle may be changed, while in many carriages the gearing also varies the ratio between the speed of the motor and the driving wheels. It is also quite common to combine in the train of gearing spur gears and sprocket wheels, and in some instances even belts. Fig. 4 illustrates a French gasoline automobile made by Underberg, of Nantes. The first figure is a side view, and the second is a plan of the truck and driving mechanism.

The motor, which is of the single cylinder type, cooled by radiation into the air, is located at N. The pinion on the end of the motor shaft engages with the wheel on the end of shaft A. This shaft carries four gears, which can be moved by means of lever C, so as to engage with corresponding gears on shaft B, thus providing four different speeds. The motion of B is transmitted to the rear axle by means of a belt that runs over the pulleys p and P, the later being carried by a differential gear, so as to run the two driving wheels at proper velocities. The circular ribs surrounding the motor cylinder are well shown in the figure, in which the carburetor of C is also seen. The housing for the motor is open at the sides so as to give air currents free access. In Fig. 4 the speed changing gears are shown, the reversing train being omitted; but if it were also drawn in, the diagram would be far more elaborate than Fig. 3.

passes from the battery through the controlling switch to the motor, and thence back to the controller and the battery. The heavy broken lines indicate the path of the current and the arrows show the direction. The velocity of the motor and the speed of the carriage are varied by varying the strength of the current, and this is effected by the movement of the controlling switch B. There are many ways in which the movement of this switch can vary the strength of the current, but an explanation of any one of them would be dry and rather technical; hence it is sufficient to say that whatever the arrangement of the connections of the controller with the other parts of the system, their relation is such that by the movement of the switch handle the speed of the motor is changed from zero to the maximum velocity.

FIGURE 2.-Double reduction.

FIGURE 3.-Single reduction.

In the majority of American vehicles the motion of the motor is transmitted to the wheels by means of spur gearing. In some cases a single motor is used, in others two; and in one or two designs that have come to public notice, four motors are employed, one for each wheel of the carriage. Fig. 2 illustrates what