208 THE ROTATION. 



For a rotation of 



Shillings. 



2695+4 + 36 + 67 + 86 + 91 + 95 + 94- 



60-90x3 _ qi .-Q 



90 years = =3153 



yu 



8273 + 4 + 36 + 67+86 + 91 + 95 + 94+ 



103-60-100x3 

 100} T ears = - 100~ =34'89 



3862 + 4+36 + 67 + 86 + 91 + 95 + 94+ 



103 + 106-60-110x3 o 7 . 7ft 



110 years = -- =3776 



120year S = 



4450+4 + 36 + 67 + 86 + 91 + 95 + 94 + 

 _ 103 + 106 + %- 60 -120x3 



It will be observed that the annual income still rises under 

 a rotation of 120 years, and will continue to do so, until the 

 volume- and quality increment become so much reduced, that 

 they will no longer cover the increase in the expenses. At 

 the same time a rotation of 120 years would involve a financial 

 loss, because interest on the invested capital has been alto- 

 gether omitted. This can easily be seen by a reference to 

 column k of the financial yield table at page 203. The net 

 soil rental under a rotation of 120 years comes to 4'50 shillings, 

 and under one of 80 years to 6*26 shillings. 



3. Rotation of the Greatest Production of Volume. 



This is the rotation under which a forest yields the greatest 

 quantity of material per unit of area ; it coincides with the 

 year in which the mean annual volume increment culminates, 

 that is to say, the year when the volume increment per cent. 



100 

 is equal to - in the case of final yield only, or equal to 



, in the case of final and intermediate returns (see 

 page 187). 



