448 Farm Mechanics. 



the upper portion of the road could not be as well drained 

 and the plan should be followed only where there is no 

 other alternative. 



551. Outlet of the Drain The drain should be turned 

 out to the side of the road whenever there is an opportunity 

 for doing so, that is, whenever there is a natural line of 

 drainage leading across the road which will answer for the 

 purpose. The free end of the drain is best made of one 

 length of cast iron sewer pipe eight feet long, because this 

 will not be injured by freezing nor be easily broken. There 

 should be a free fall at the end of the drain, and it is better 

 that the opening should be protected by some sort of metal 

 grating or screen to prevent animals from running in in 

 dry times. 



552. Size of Tile. Tile three inches in diameter is the 

 best to use for the reason that, in case the grade is very 

 small, slight errors in laying the line cannot carry the en- 

 tire opening of the tile above or below the grade line and 

 hence permit the drain to be entirely closed by silt. 



553. Kind of Tile. Where the tile can be laid two feet 

 or more below the surface of the road ordinary drain tile 

 which are well burned, straight, smooth inside and having 

 the ends cut squarely off so that they may fit closely to- 

 gether are best. Great care should be taken in placing the 

 tile to turn them until the ends fit very closely all the way 

 around, and then to fix them rigidly there. This care is 

 aeeded in order to prevent silt from being washed in at 

 the joints. 



Where the tile must come less than two feet below the 

 surface it will be safer cither to use the vitrified drain tile 

 or else second quality sewer tile not likely to be disinte- 

 grated by frost. 



554. Surface Drainage. The quick removal of water 

 from the surface of a road and the prevention of seepage 



