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POPULAR SCIENCE MONTHLY. 



be changed, while in many carriages the gearing also varies the ratio be- 

 tween 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 latter being carried by a 

 differential gear, so as to run the two driving wheels at proper velocities. 



Fig. 5. <herrier Two-speed Gear. 



The circular ribs surrounding the motor cylinder are well shown in the 

 figure, in which the carburator 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. 



Another form of variable speed gear is shown in Fig. 5. This pro- 

 vides for two speeds. The large wheel E is on the carriage axle, and it 

 is driven either by a pinion F, or by J. Upon the shaft there ar*» 

 two friction clutches C D, and when C acts the pinion F drives E, and 

 when D acts the pinion G drives H, which in turn drives /, and this 

 wheel is mounted on the same shaft as J. 



Some of the best-known makers of gasoline vehicles do not employ 

 variable gears and depend for changes in the speed wholly upon varia- 

 tion in the velocity of the motor. The De Dion carriages are made in 

 this way, the gearing being substantially as illustrated in Fig. 3. 



