48 THE AFFORESTATION OF SURPLUS LAND. 



wanted, for instance, for fencing or pit props. In these cases 

 the treatment differs considerably. Let us suppose we grow 

 larch, or Scotch pine, or spruce under a rotation of forty years. 

 In that case we should probably make two thinnings, say at 

 the age of fifteen and twenty-five years in the case of larch, 

 and at twenty and thirty years in the case of Scotch pine and 

 spruce. These thinnings would be heavier than when large 

 clean timber is to be produced. 



Supposing we have planted larch on fairly good land and 

 remove the original 2,700 plants as follows : 



Number of poles removed at the age of 15 years =: 1,400 



25 = 600 

 40 = 700 



Total .... 2,700 

 Then we can count on the following receipts : 



.. d. 



Thinning in the year 15 say . . 10 



25 . . 30 



Final cutting in the year 40 ., . . 70 



The per cent, on the investment comes out as follows, if 

 the other data remain as before : 



Per cent. 



Cost price of land = 5, interest . . =9 



10 7 



,, ,, =15 ,, . . = 5'6 



20 = 4-8 



25 . 4-3 



= 30 3-9 



,, ,, = 35 ,, . . 3'G 



,, ,, 40 . . = 3'4 



,, ,, 45 ,, . = 3'1 



^50 = 2-9 



