VON MANTEL'S METHOD. 



103 



prevailing in North Kheri no argument can justify a 

 longer rotation than 90 years and this is the rotation 

 adopted. 



" The yield will be determined by volume for the whole working 

 circle on the following data : 



Area. 47,000 acres. 



Quality class. II Quality. 



Growing stock. All sal and asaina over 8" diameter have been 

 enumerated in the standard diameter classes. The 

 following tabular statement has been based on the result 

 of these enumerations : 



The calculation of the yield for this working circle can now 

 be proceeded with. 



" The formula adopted for calculating the yield from the grow- 

 ing stock enumerated down to 8* diameter is a simple one worked 

 outbyMjssra. Blanfordaad Simmoas and is as follows- 



47 



Y= 



><-> 



where V=the total growing stock (both 

 timber and smallwood) of trees 

 enumerated over 8" diameter. 

 R = the rotation 

 X = the age of 8" trees. 



In this case (disregarding establishment period) 

 V = 229'3 units per acre. 

 R = 80 years. 



Hence Y = 



220-3 



( 1 _*.x=6'826 units per acre. 

 25) 



