QUALITY OF WOODS. 273 



yield capacity, the area to be placed in each is also obtained 

 by calculating with the inverse proportion of the qualities. 



Example : The above forest shall be divided into ten coupes 

 of equal yield capacity ; then the reduced area of each coupe 



comes to = ^ = 100 acres. The real area of a coupe in 

 each block is calculated as follows : 



Block (1) 60 : 40 = 100 ; x and x = 4 * 10 Q = 66'67 acres 



60 



(2)50:40 = 100:* a; = 40 * 1QO = 80'00 



50 



(3)40:40 = 100:* x = 4 * = lOO'OO 



40 



(4)30:40 = 100:* * = 40 * 100 = 133*33 



oO 



or : 



Coupe No. 1 = 66-67= 66'67 acres ^ n 



9 fifi-fi7 fifi-AT 1 Taken from block 



2= bbb7 = bb b7 j- 1 



,,3= 66-66= 66-66 J 



4= 80-00= 80-00 From block No. 2. 



5=20+75= 95-00 



( and partly No. 3. 



6= 100 = 100 From block No. 3. 

 7-25-4-100- 125 i Partly fr m N ' 3 



,, < ZO-hlUU 140 ,, < 



(. and partly No. 4. 

 8= 133-33= 133-33 ^ 

 ,,9= 133-33= 133-33 I From block No. 4. 

 ,,10= 133-34= 133-34 J 



Total . . 1000-00 acres. 



(&) Calculation with any Suitable Quality. In this case any 

 quality can be used, whether it exists on the area or not. 



The total reduced area is obtained by multiplying the several 

 qualities by the corresponding areas and dividing the product 

 by the selected standard quality. The total reduced area may 



