156 Farm Mechanics. 



out the aid of foreign material. Of course by grading it 

 into proper form so as to secure the needed drainage the 

 road will be good when it is not wet, and under these con- 

 ditions it will remain fair much longer than if not so pre- 

 pared because, when this soil has been once thoroughly com- 

 pacted and dry, water enters it very slowly, so that it is 

 only during long wet spells and when the frost is going out 

 that the most serious injury to the road comes. 



566. Clay Roads Surfaced With Gravel. Where gravel of 

 suitable quality is available a covering of three or 

 four inches, thoroughly rolled and packed, will very greatly 

 improve the surface of a clay road, preventing it from soft- 

 ening so readily with every rain and with the action of 

 frost. Even sand and good loam, where nothing better is 

 available, will improve the quality. 



In some cases burning the clay has been practiced so as 

 to render it less plastic and sticky, but this practice will be 

 one of the last to be resorted to at this time of cheap trans- 

 portation and high price of fuel. 



567. Sandy Roads. The making of good roads in a coun- 

 try of very sandy soil is extremely difficult on account of 

 the nearly complete absence of binding properties in the 

 sand when dry. If there were any cheap method of keep- 

 ing the surface wet, sand would make an excellent road. 

 Even the rounded grains of beach sand for a short time 

 after the waves have withdrawn are so tightly bonded that 

 a horse may canter along the beach, making but little im- 

 pression upon it. The water, however, drains away so 

 rapidly from the coarse clean rounded grains that there is 

 no longer anything to bind them together, and the foot or 

 wheel easily sets them aside. When, however, there are a 

 sufficient number of much finer particles commingled with 

 the coarse sand grains a loam is the result whose water 

 holding power is increased so that for a longer time the 

 grains are bonded together by it, enabling the loam to form 

 the better road. On the other hand, the amount of water 



