1 68 FOREST VAI^UATION 



13. What is the growth, in quality in per cent, for each decade 

 which will keep the growth in value constant between the ages 40 

 and 100 years in spruce, site II, as in Schwappach tables? 



14. Eight hundred acres of timber is cut over every 10 years 

 and nets $12 per acre at each cut. Expenses per acre: taxes 15 

 cents, protection 10 cents. What is the value of the forest at 2% 

 and at 3%? What is 100 years lease worth if the last cut came 6 

 years ago? 



15. One hundred acres of land may be farmed. At farming 

 it brings 75 cents per acre net. If planted to pine and r = 8o years ; 

 Yr=6o cords at $3; C."^$io; e-=25 cents; p = 4, 3, and 2% — 

 which use is more profitable? 



16. Six thousand acres of Xorth Carolina pinery cut over lands 

 bought at $5 per acre : expenses per acre : taxes 10 cents, protection 

 5 cents, p = 3% ; what is Fc in 25 years? If timber is $6 per M. 

 feet, how much must one get to make interest and expenses, and 

 leave the forest as good as when bought? 



17. Mountain lands in Pennsylvania; can return every 15 

 years for 6 cords of hardwood stuff, mostly coppice, worth $2 per 

 cord on stump. Taxes 5 cents per acre ; no other charges ; what is 

 the value of the woods at 3%? 



18. A farmer has 60 acres inferior lands ; he paid $18 an acre. 

 He has rented this at $1 per acre for pasture. Expenses per acre : 

 taxes 15 cents, fences 10 cents, p = 3%. He plants up 30 acres to 

 hardwoods. C:=$io, first cut when 15 years old. How much must 

 he cut if income is to be as good as at pasture use, if he values stuff 

 at $2 per cord? 



19. One hundred acres coppice ; non-agricultural land, can be 

 cut every 20 years for 15 cords of stuff, last cut 9 years ago, stump- 

 age now $1 per cord. Expected rise in market price 20 cents per 

 cord for each of the next 5 rotations ; after this constant. What is 

 this woods worth at 3% ? 



20. Four thousand acres of pine woods in Xorth Carohna can 

 be cut over every 15 years for 5 W. feet. Last cut 7 years ago. 

 What yearly payment or annuity can a trust company pay if they 

 rate money at 3% ? 



21. One thousand acres of coppice woods in Pennsylvania have 

 cut 15 cords every 25 years for iron furnace; stumpage $1.50. Plan 

 is to convert into spruce for pulp on 50 year rotation. If Yr = 30 

 cords at $5 ; C^$io; thin. =0; taxes in fir.st case 15 cents, in new 

 case 10% of stumpage as yield tax ; protection and care := 10 cents ; 

 p = 3%. Plow do the two compare? 



