TILE DRAINING. 367 



main with a branch to receive the lateral ; and Fig. 5 the 



FIG. 4. 



manner of laying the tiles at the junction of a lateral drain 

 with the main. 



FIG. 5. 



Rules to ~be observed in mciking Tile Drains : 



1. Every drain (unless there is some special reason to 

 the contrary) should run directly down the steepest de- 

 scent of the land not obliquely, but straight down the hill. 



2. Wherever possible, the drains should be four feet 

 deep, especially when the subsoil is a stiff clay hard-pan. 



3. When the drains are four feet deep, they should be 

 forty feet apart. If only three feet deep, they should be 

 only twenty feet apart ; and if more than four feet, they 

 may safely be placed at greater distances than forty feet. 



