THE THEORY AND PRACTICE OF WORKING PLANS 115 



Let X (the period of equalization) =- = = 40 years. 



4 4 

 Then by the formula: 



+,X,_,„, ^ 6.8io.oco+(so.58oX4°)-4,046,40o 

 X 40 



= 119,670 feet board measure. 



The annual cut therefore equals 119,670 feet board measure. 



The cut for the decade equals 1,196,700 feet board measure. 



There is w'ithin compartments gb, 10, and part of 6 and 8 

 ample (2,675 ^^- ^^et) for the cutting within the next decade. 

 Compartments 6 and 8 need scarcely be touched, which is just 

 as well, since they are barely mature now. If, however, in view 

 of the proportionately large amount of mature and overmature 

 timber it is desired to reduce the period of distributing the 

 surplus to ten years, the result would be: 



6,810,000+ (so, sSoX 10)— 4,046,400 , 



— ^^-^^ — ^ — =326,940. 



The annual cut therefore equals 326,940 feet board measure. 



The cut for the decade equals 3,269,400 feet board measure. 



There are within compartments 9, 10, 6, and 8 only 2,675,000 

 feet, hence the management must either be conservative and 

 content itself therewith or add compartment 4, wath 945,000 

 feet to the cutting areas for the decade, which would make 

 3,620,000 feet board measure, or ample whereon to draw for 

 the 3,269,400 feet board measure to be cut. 



(c) Value and Application. — This method is without doubt 

 the most rational of all the methods of determining the cut; 

 for it attempts no iron-clad rule or framework — such as the 

 " period methods " next to be considered — but depends entirely 

 on the siMcultural and economical requirements of the forest. 

 By means of frequent re\dsions the amount cut can never 

 endanger the continuity of the forest's productiveness, while it 

 allows full play to the skill of the officer in charge of the manage- 

 ment of the forest. The forest moves steadily toward a normal 



