48 



SPRINGS 



CH. Ill 



ones. ' Nimrod' gives 4 ft. 8 in. as a usual height of 

 the hind wheels in old coaches. The wheels of an 

 American Concord coach are 5 ft. 1 in. and 3 ft. 10 

 in. There are usually twelve spokes in the hind 

 wheels and ten in the front wheels, but in the old 

 English coaches there were frequently fourteen and 

 twelve, respectively, and these are the numbers in 

 the Concord wheels.* 



What is now usually called the 'patent wheel/ 

 the characteristic of which is a hub formed by two 

 iron plates applied to the back and front of the 

 spokes, is not particularly new ; it is described in 

 Adams's book, published in 1837. It is used exten- 

 sively on business wagons but not on fine work. 



Springs. — Coaches are hung upon what coach- 

 ing men usually call 

 telegraph springs 

 (because they were 

 first used in Eng- 

 land on the Man- 

 chester 'Telegraph'),. 



but known by coach- 



riG. 27. J 



makers as platform 

 springs, which permit the body of the coach to be 

 hung low (Fig. 27). 



* The following dimensions of the wheel of a very light, one-man 

 trotting buggy, are given for the purpose of comparison with coach 

 wheels : height, 48 in. ; diameter of hub, 2i in. ; diameter of axle. 

 I in., taper; dish, -f\ in. from outer spoke; swing or overhang of 



