DRAINAGE OF LAND 65 



" cuts ; " any system of pipe drainage is of course out of the 

 question. 



Any systematic "herring bone" drainage, as is adopted 

 on agricultural land, can seldom, if ever, be adopted in forestry, 

 if a profit be desired. 



Fortunately it is, generally speaking, only on stiff clay 

 soils where such a course would ever be wanted. Now, 

 supposing that open "cuts" be made 21 feet apart on flat 

 stiff clay land, the cost per acre, including a contribution 

 towards " mains " and culverts, would amount to about 

 4, I os. But this sum is prohibitive ; for forest growth is 

 very slow on stiff clay lands, and a profit would seldom be 

 earned on this additional outlay. 



However, much benefit will often accrue on such land by 

 making a certain number of channels, so as to lead superfluous 

 water off as quickly as possible. 



Open ditches should be cut on one or both sides of the 

 rides in such plantations, and branch channels at intervals 

 should discharge at an acute angle into them. 



The branch channels dissecting the compartments should 

 have an average depth of 3 feet, and should be about 

 1 5 inches wide, and cut with practically a vertical face ; and 

 the main channels should have an average depth of 3 feet 

 6 inches. 



Culverts must be provided where these channels cross the 

 rides ; they may be made " box-shaped " with 2-inch creosoted 

 planks, or else concrete pipes, 12 to 24 inches diameter, may 

 be used. These home-made concrete culverts are very much 

 cheaper than purchased pipes of similar bore. 



The open ditches by the sides of the rides serve not only 

 for carrying off water, but also as convenient points for com- 

 bating forest " ground " fires. 



Cost of Draining. The cost of making the " cuts " 3 feet 

 deep, will on stiff clay soil be 8d. a rod ; and if the " cuts " be 

 3 feet 6 inches deep, lod. a rod. 



Now, if an area of 40 acres were divided up by channels 

 into blocks 44 yards by 44 yards (i.e. just under half an acre 

 each), there would be 40 rods of " cuts " or " ditches " to be 



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