45 8 FUNDAMENTALS OF AGRICULTURE. 



scraping grader as shown in the figure, which makes 

 the cost of construction low. To make a road more 

 nearly level, hills must be cut down and hollows filled 

 by means of machines designed to carry earth for some 

 distance. After a road has been formed, it is desirable 

 that the crown be made as firm as possible with a heavy 

 roller, but the travel may be depended upon to do this 

 work. 



Side Ditches. After the water is shed from off 

 the crown, it is necessary to have side ditches to carry 

 the water along the road to points where it may be 

 turned into natural water courses. These ditches 

 should be of a form which may be easily constructed 

 at a low cost, and they should be ample in size to carry 

 away the water after a heavy rainfall. They should 

 not be so deep as to be dangerous should a vehicle be 

 driven into them, and their form should be such as 

 to permit them to be easily cleaned. The side ditches 

 will fulfil in a large measure all of these requirements. 

 The side ditches should be provided with a uniform 

 slope to a good outlet. It is rarely possible for a good 

 road to exist where water stands in ponds in the side 

 ditches. 



Under drainage. Ground water must not stand 

 within three or four feet of the road surface, or it 

 will pass to the surface by capillary action, and not 

 only soften the foundation, but the road proper. No 

 road material will sustain a heavy load unless the 

 foundation on which it rests is firm and solid. Earth 

 will not make a good foundation if saturated with 

 water. Not only will the water soften the road and 

 its foundation, but in climates where the ground is 

 frozen during the winter seasons the action of frost is 

 very destructive where water is present, due to its 

 heaving action or expansion upon freezing. 



Most earth roads are provided with natural under- 

 drainage; that is, the ground water does not lie within 

 three or four feet of the surface. But where natural 

 underdrainage does not exist, artificial underdrainage 



