BY DRAINING. CONSTRUCTION OF DRAINS. 



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cheapest, most durable and most effectual ; for, aside from their 

 convenience, a considerable quantity of land is saved for cul- 

 tivation. 



(Fig. 15.) 



Before constructing a drain for this purpose, it is neces- 

 sary to examine the land, and ascertain where the springs 

 are. Most cases of surface-draining refer to swamps, or 

 low lands. Suppose BOD (Fig. 15) is a swamp, or low 

 ground in which the water collects, either from the high 

 lands, or from springs in the margin B D, or anywhere in 

 the centre of the meadow. The first thing to be done, in 

 this case, is to make an outlet for conducting the water away 

 to some stream as at O S. The second is to run a drain 

 through the centre from Cto O, and all around the margin 

 B D, to cut off the springs, and to conduct the water into the 

 main drain A, or outlet. In each case these drains should 

 be sunk into the sub-soil, and if much water flow in them 

 they should be open, especially the central drain. In this 

 way the swamp can be rendered perfectly dry and capable of 

 being cultivated. 



Construction of under-ground drains. Under-ground 

 drains should be from two to three feet in depth, in order 

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