KJ;GUI.ATTON OF CUT 169 



3. J'ases of estimating the proper cut. 

 Actual Growing Stock : 



12.000 ft. of merchantable size, regular cruise. 



4,000 ft. of non-merchantable sizes by estimate or compari- 



son to merchantable stuff.* 



Total 16,000 ft. b. m. 



N' 1 /^ -CI .10,000 ft. ,^ . 



i\ormal Growmg btock = 15.000 ft. b. m. 



2 



16,000 (ft.) 



Actual Growth = ; : — :^ tj-j ft. per acre and vear. 



120 (rotation) "^" ' 



4. Von Mantel's formula. 



Cut = 2G/r. 



2 X 1 1,000 million 



In our case: Cut=^ = about 180 million. 



120 



5. Regulation by the Austrian Method. 

 Ga — Gn 



Cut: Growth 



16000 — i^ooo 



In this case : Cut = 133 -I- ' = 153 ft. per acre, or 



153 million ft. all told. 



Denominator a is made only fifty years because there is no large 

 gap in age classes here as in the Lodge Pole case cited before, and 

 fifty years seemed quite sufficient to spread the small surplus, es- 

 ]iecially in view of the fact that a considerable amount of large 

 select stuff is rapidly becoming spike top and "going back." 



6. Modified Fixed Yearly Cut. Since it appears desirable to 

 cut on .tielection plan and cut the property over as rapidly as pos- 

 sible to avoid loss of large, old stuff, the attempt is made to cut over 

 in twenty-five years, or about 40,000 acres per year. 



Taking not over 30% of total, about 4.5 M. ft. per acre the cut 

 per year is: 4.5 M. X 40,000= 180 million ft. Here, as in the 



* Calculation of growth and growing stock in feet board measure always 

 involves a certain apparent fallacy. In speaking of the average growth of 

 ripe timber per acre, the stand 10, or 20 years old is also included, though, of 

 course, there is no material here as yet to make any sawed stuff of any kind. 



