1 88 AGRICULTURE. 



the only kind of road possible in certain places, but in order 

 to be useful they must be kept well rounded up and well 

 drained on the sides. The greatest enemy of all roads is water, 

 whether it is water in the material of the road or on the surface 

 of the road. The frost can do no damage unless there is water 

 in the road. You know that water expands when it freezes, so 

 that when a wet road freezes it heaves, and becomes broken 

 up. This, then, is the first principle of road-making keep it 

 dry by open drains on the side, or by covered tile drains on 

 the side, or by tile drains below the road. 



The next principle in road-making is to get a fairly hard 

 surface. In early days the settlers sometimes cut down small 

 trees, and, after trimming them, laid them side by side across 

 the dirt road. By this means there was made a surface that 

 was hard but a little rough. Such a road, from its ribbed 

 nature, was called a "corduroy" road. Later on, when saw- 

 mills became common, sawn-planks were sometimes laid down, 

 forming a plank road. The object in both cases was to 

 get a hard, level surface. A horse can pull but a light load 

 through loose sand or deep miry mud ; he can draw much 

 more on a hard, level road ; he can draw still more on a level 

 steel track. Why is this so ? 



GRAVEL ROADS. Another way to harden the surface is to 

 put hard, stony material upon it. First of all, good gravel 

 may be used, and a coating of it laid along the roadway. You 

 will at once ask as to whether loose gravel will not be difficult 

 to drive through. So it is. Therefore we must get the gravel 

 well packed together, and so a roller is used. After first 

 rolling the dirt roadway, a layer of gravel is put on, and the 

 heavy roller is again driven back and forth, every time crush- 

 ing the gravel down a little, and packing it together a little 

 more closely. This should be done scores of times if neces- 

 sary. The number of times will, of course, depend upon the 

 weight of the roller; a heavy 2o-ton steam roller will not need 



