ROADS. 189 



to be passed over the gravel as often as a 6-ton roller drawn 

 by two teams of horses. Unless the gravel is rolled in this 

 way, it remains loose and soft when the fall rains come on, 

 the wheels of wagons cut through it, and mix it with the mud 

 beneath ; and so the gravel is wasted and the road is not nearly 

 so good as it should be. Then more gravel is put on and 

 rolled again, and a nicely rounded or crowned surface is made 

 which will shed the rain-water into the side ditches, and 

 which is so hard and compact on the surface that the wheels 

 will not cut through. 



But big open ditches on the side are unsightly ; they get 

 choked up with weeds, and they are frequently dangerous to 

 horses and travellers. They should be kept clean, of course, 

 so that the water will not stand in them. But the better plan 

 is to put down a covered tile drain on each side of the road, 

 and leave only a shallow ditch above it. The grass will grow 

 over this, and a neat roadside will result. 





Fig. 83. A gravel road properly crowned, with side ditches and tile drains. 



In order to get a strong, tough surface, the gravel must be 

 well packed together, that is, it must "bind." If we mix 

 together in the road coarse gravel and fine hard stony material 

 and soft fine dirt the road will soon become uneven. It is 

 necessary, therefore, to have the gravel well screened ; then 

 the coarser part should be spread on the roadway and well 

 rolled, and the finer gravel spread upon it to form the surface. 

 All soft material, such as sods and loose dirt, should be kept 



