188 

 and 



THE INCREMENT. 





 100' 



Introducing this value into the above formula of p v , the 

 latter becomes : 



,_100/., , txv' \_100 + 

 ~V~\ + 100x7/~ ~7~ 



The formula? p v = ~ and p v ' = - ^ are used to gauge the 



ripeness of growing woods which are worked for volume of 

 production only. If it is found that the increment per cent. 



YIELD TABLE FOB ONE ACRE OF A SCOTCH PINE WOOD, 



Timber down to 



