SPRING BUFFERS. 215 



Nowadays, instead of the solid wooden blocks, 

 there is at each corner of the carriage a spring 

 buffer, one of which is shown in a section at fig. 3. 

 When the carriages are coupled, they are drawn 

 together by double screws, so that the buffers are 

 not only in contact, but press slightly upon the 

 springs, as is seen at A. Thus, the train becomes 

 a single body, instead of being a row of separate 

 carriages, and a good driver can start or stop the 

 train so quietly, that the passengers, if not guided 

 by the sense of sight, can scarcely tell when they 

 have started or stopped. 



It is evident that if any of the carriages were 

 to be screwed so tightly together that the buffers 

 were forced back to their farthest limits, as shown 

 at B, the elasticity would be destroyed, and the 

 buffers rendered useless. 



Now, a bearing-rein of any kind interferes with 

 the wonderful system of elastic structures which 

 have been described. Even if it be a very mild one, 

 it hinders the play of the vertebrae upon each other. 

 The horse's head being tied to the saddle by the 

 bearing-rein, and the saddle being fastened to the 

 tail by the crupper, the horse's head is practically 

 tied to his tail, thus interfering with the elasticity 

 which demands freedom throughout the entire 

 length. 



