PART IV. 



AGRICULTURE. 



231 



length ; but, on the contrary, some benefit results, to draught 

 cattle at least, from having a variation of surface to pass over, 

 as it varies the line of draught, and rests it alternately on dif- 

 ferent parts of the body. Something of this kind takes place 

 in walking, as every one accustomed to use this exercise in any 

 considerable degree must have experienced. 



2. The formation of roads. The first requisite is to lay 

 them dry, by open drains at each side, which must be of a 

 depth and width proportionate to the road. When the latter 

 is narrow, and the drains deep, the pressure of carriages is apt 

 to cut the surface and derange the materials. The surface of 

 the road in level countries is generally made somewhat convex, 

 in order to throw off the rain; but in mountainous districts it is 

 perfectly level ; and in some places concave roads have been 

 adopted with considerable advantages. 



3. The management of roads refers to cleaning and repairing 

 them. Excellent management does not consist so much in 

 doing a great deal, as in a constant attendance and repara- 

 tion of every little injury; by this means roads may be kept in 

 proper order for a great length of time, and at a small expence. 



On canal making I do not judge it necessary to advance 

 any thing, as it is a branch of national improvement in which 



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