50 SPRINGS CH. Ill 



is better to make the shackles short and close, 

 giving them as little play as possible. They should 

 be covered with leather, to prevent rattling. 



According to Corbett (p. 28), the telegraph 

 springs were used on coaches before they were 

 used on the mails, and after the expiration of Vid- 

 ler's contract in 1836, they were put on the mails, 

 which appear to have been hung originally with a 

 cross spring behind. 



Springs are always made of several plates, or 

 leaves, which give more elasticity than would be ob- 

 tained with one plate of steel of the same strength, 

 and are also less liable to break from a sudden 

 shock or rebound, which is communicated succes- 

 sively to the plates. 



The springs are fastened to the bed, and to the 

 body, by clips, which embrace them, so as not to 

 have holes through their centres. 



In many business wagons, three-quarter springs, 

 shown in Fig. 28, called in England ' dennet springs,' 



are used. The front 

 ends of the side 

 springs are fastened 

 directly to the body, 

 or to the carriage- 

 part, as the case may 

 be, and there are 

 ' therefore six points 



of attachment, four of them so far apart side- 

 ways as to resist a rolling motion much better 



