INSTRUMENTS USEFUL TO A WOODSMAN. 



95 



The increase in board-foot contents due to growth in loblolly pine 

 shows, according to the Scribner Rule, the following relation to the 

 growth per cent in total volume given in the table on page 93: 





Relation of board foot 



Diameter of 



(Scribner) increment 



the tree. 



to total volume incre- 





ment. 



Inches. 



Times. 



8 



2.1 



10 



1.4 



12 



1.2 



18 



1.1 



24 



1.1 



36 



1.0 



i# 



It is seen that the volume growth per cent, whether taken as 

 total tree volume, saw cut, or Scribner Rule, is almost the same 

 for trees over 18 inches. 



In addition to growth in volume, trees increase in value with size 

 fester than the volume indicates, since there is a greater proportion 

 of the better grades of lumber in the larger trees. Thus white pine 

 etumpage in 24-inch trees is worth at least twice that in 12-inch 

 trees. This is an extremely variable factor, however. 



Again, stumpage tends to increase in price with time, even were 

 there no increase in growth. 



To summarize, then, the profitableness of letting trees grow is 

 determined by the percentage of wood laid on, the extra increase 

 in board-foot product coming with increased size, the larger stump- 

 age price paid for larger material, and the constant tendency for 

 etumpage to increase even without growth. The first two factors 

 may be approximated; the last two can not be dealt with according 

 to fixed rules. 



SPECIAL INSTRUMENTS USEFUL TO A WOODSMAN. 



It is unnecessary to describe the instruments which are familiar 



to every woodsman. It is believed, however, that those described 



in the following pages are not generally known, at least in the form 



i|^ecommended. They will prove useful in many cases to cruisers 



and other woodsmen. Further information regarding the instru- 



