EVOLUTIOX OF THE A CJ'< /MOBILE. 



419 



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 con- 

 nection, are with few exceptions very different. 



A careful examination of Figs. 11, 14 and 17 will show that from 

 an artistic point of view these examples of steam carriages are satis- 

 factory. In regard to their operation it can be said that they have 

 sufficient power to run up the steepest grades encountered on ordinary 

 roads at a fair rate of speed, while on level ground their velocity is 

 more than enough to satisfy the average rider. The danger of ex- 

 plosion is so remote that it need not be considered. The Serpollet 



boiler is practically mexplosive, while those used in the American 

 vehicles are so constructed that they can withstand a pressure far 

 greater than any they can be subjected to in practice. It might be 

 expected that the motion of the machinery would produce an unpleasant 

 vibration, but on account of the lightness of the moving parts and 

 careful balancing, this effect is much reduced. The use of gasoline 

 as fuel, in connection with automatic burners, eliminates the smoke 

 and ashes incident to the use of coal, and in addition reduces the labor 

 of handling the vehicle, as no attention need be given to the mechanism 

 other than to see that the water in the boiler is maintained at the 

 proper level. In the case of the Serpollet carriages, not even this point 

 need be looked after, as the feed of the boiler is perfectly automatic. 



