The Canadian Horticulturist. 



413 



The Centre of the road should be excavated to receive the gravel or crushed 

 stone. Where this care cannot be taken the metal may be placed on the centre 

 and the sides graded up. The crown of the road should be obtained chiefly by 

 rounding up the natural soil, but the metal should be several inches deeper in 

 the centre than at the sides. On country roads, a crown of one inch rise to one 

 foot of width from the side to the centre is generally sufificient ; on hills it may 

 be greater so as to prevent the water following the wheel tracks and deepening 

 them to ruts. 



As an illustration of the advantages of permanent work along this line, the 

 bulletin gives several engravings, some of which by kindness of the Minister 

 of Agriculture, we give in connection with this extract. 



Fk;. 1019. — Metcalfe Street. St. Thomas. 



^ 



The roadway twenty-two feet wide and curbed with 3 x 10 cedar, is made with a five inch rough 

 flake-stone foundation and covered with clean coursed gravel, seven inches in depth after being 

 consolidated with a heavy roller. It was built in 1892, and the photograph taken May, i8g6. 



The width of a roadway to be metalled depends upon the amount of traffic 

 it will be required to accommodate. Eight feet will be ample for the majority 

 of roads in rural districts. Roads forming the approach to towns may some- 

 times be mettled to a width of sixteen feet. The depth of metalling need never 

 exceed after consolidation twelve inches, if of a good quality and clean, and 

 eight inches is the least which should ever be employed, the thickness varying 

 with the amount of traffic. It should be placed on in layers, and each layer 

 thoroughly rolled, the subsoil having first been well consolidated. 



