20 DRAINAGE. 



When the site is on the side or foot of a hill, it is gener- 

 ally necessary to cut off the water that drains from the 

 higher level, by constructing drains across the hill and 

 connecting these with drains at right angles running 

 down through the garden site. The accompanying dia- 

 gram more fully explains this. 



The two upper sloping lines represent two drains on 

 the higher level which intercept the water draining from 

 the hill, and the parallel lines running down the descent 

 through the garden, indicate drains either discharging into 

 a pond or brook, or connecting with a main drain which 

 conveys the water to some proper outlet of discharge. If 

 the land is on a ridge the lateral drains should be right up 



and down the slope of the land, and connect with main 

 drains in the depression; as in the above diagram. 



