CHAPTER XXVI 



STONE ROADS 



Stone roads include all roads on which broken stone is 

 used as the principal surfacing material. Stone has been 

 used in road construction from very early times, where 

 first-class roads were desired. 



Telford Roads. Some broken stone roads are given the 

 name of Telford, when they incorporate some features of 

 road construction which were used by Mr. Thomas Telford, 

 a famous English engineer. The distinguishing feature of 

 the old Telford road was that the lower course or layer of 

 stone was made of rather large flat stones laid in place by 

 hand. At the present time any road which uses large pieces 

 of material in the base or lower layer may be called a Tel- 

 ford road. 



Macadam Road. Most stone roads which have been 

 built in recent years follow the form of construction proposed 

 by John Loudon McAdam, another famous English road 

 engineer, who lived between 1756 and 1836. So general is 

 the use of this construction that it has become customary to 

 call all broken-stone roads macadam roads. 



Macadam roads are made of broken stone throughout. 

 The stone is applied in three or more layers, and in the usual 

 construction it is customary to place the larger fragments in 

 the lower course. 



Road Stone. Not all kinds of stone can be used success- 

 fully in the construction of stone roads. Good road stone 

 must be hard so that it will not be crushed by the traffic 

 which will come upon it. It must also be hard enough to 



160 



