210 FARM ARITHMETIC. 



The forests have a very important influence upon the rain- 

 fall and floods. 



Forestry means the science and art of making the best 

 permanent use of the forest. If a forest is cut in such 

 a way that no new forest growth of value follows, its 

 usefulness is permanently destroyed. If it is so cut that 

 it afterwards produces less timber than in its natural 

 state, or timber of inferior quality, its usefulness is im- 

 paired. Few farmers give sufiicient thought to the cul- 

 tivation of their forests, or even know whether the treat- 

 ment which they are receiving will make them better or 

 worse. This is bad farming. With proper care a forest 

 can be made to grow more and better timber in a given 

 time than it would if left to itself. Use should cause a 

 forest to improve and not to deteriorate. 



The farmers of the United States own approximately 

 three hundred million acres of woodland. This is a 

 tremendously productive resource. IMost of this wood- 

 land, however, is in a run-down condition. The differ- 

 ence between what it now produces and what it might 

 produce with intelligent care is a great loss which the 

 country suffers on account of careless, wasteful, and 

 shortsighted methods. The difference between what the 

 farmer now gets and what he should get is a loss for 

 which he is himself responsible. 



751. A long leaf pine tree produces three logs, con- 

 taining 10, 24, and 44 cubic feet respectively. Assuming 

 that from each cubic foot seven board feet are secured, 

 and that long leaf pine lumber is worth $6 a thousand on 

 the stump, how much is the tree worth? 



752. A farmer wishes to build a fence around a square 

 farm of 160 acres. The posts are to be 16>^ feet apart. 

 How many posts will it take ? 



