ECCENTBIC BUFFERS. 



immediately removed, if there be a fog at the time, or any other 

 cause which may prevent the driver of a following train from 

 seeing the obstacle, the guard or policeman runs back along the 

 line and places these balls on the rails at certain distances, so 

 that when a train approaches it causes them successively to 

 explode in rolling over them, and the driver thus receives 

 ^warning to stop. 



33. The evil consequences resulting from collision are fre- 

 quently aggravated by the manner in which the carriages or 

 waggons composing the trains are connected with or adapted to 

 each other. The mode of connecting the successive carriages 

 ibrming a train is as follows. From the end of the frame 

 supporting each carriage project two strong iron rods, which 

 rest against spiral springs, and which are terminated by circular 

 cushions, about a foot in diameter, called buffers. "When two 

 successive coaches are brought into contact, these buffers ought 

 to meet each other so that their centres should coincide. This 

 requires that the buffers of all the carriages should have the 

 same gauge, that is to say, that there should be the same 

 distance between their centres ; and, secondly, that they should 

 be at the same height above the rails. If this be not the case, a 

 collision would have the effect of causing one carriage to push 

 the other either aside or upwards, as the case might be ; aside if 

 the centre of the buffer deviated horizontally, and' upwards if it 

 deviated vertically. 



In any case there would be a tendency of the coaches to throw 

 each other off the rails. 



The successive coaches forming a train were originally held 

 together by a chain, which was necessarily always a little slack, 

 so that when the power of the engine was driving the train, the 

 buffers were not in close contact, and whenever the train stopped, 

 or even slackened its speed, the hinder carriages ran against the 

 foremost ones with a collision, the force of which was proportional 

 to the difference of their speeds. 



This mode of connection was replaced by a coupling screw, by 

 means of which the carriages are drawn together, so that the 

 buffers are pressed into close contact, and their springs a little 

 compressed. 



In this manner the train is formed into one complete column, 

 and the change of speed to which it is subject does not produce 

 the partial collision just mentioned. 



One of the means, therefore, of diminishing the chances of 

 injuries resulting from collision is to provide against the occur- 

 rence of eccentric buffers, and to ensure the proper coupling of 

 the trains. 



175 



