THE ECONOMIC IMPORTANCE OF FORESTS 503 



tection are taught. For those unable to attend these institutions, 

 many bulletins and other publications are available from state 

 and national governments, giving valuable information regard- 

 ing this important source of our natural wealth. 



The farmer who would cut down his apple trees to gather the 

 fruit, or who harvested a crop without planting another, would 

 be considered insane, yet the treatment of our forest resources 

 amounts almost to this. The sooner we realize the fact that a 

 forest is a crop to be tended and gathered, planted, and protected 

 like any other, the sooner our lumber, paper, and other products 

 will cease to increase in cost. 



TIMBER STRUCTURE 



A great deal of the value of lumber depends on one of three 

 factors, its durability, strength, or appearance. These in turn 

 depend upon the minute structure of the tree stem and though 

 this was discussed in Chapter XI, it needs to be recalled in this 

 connection. 



A woody stem is made up of wood fibers and ducts (tracheids 

 in the evergreens). These are arranged in annual rings caused 

 by larger ducts forming in the spring, and fewer and smaller ones 

 in autumn and winter. 



" Grain." Evidently a board cut from such a stem will have 

 alternate layers of harder and softer tissue which cause the 

 " grain " seen in most woods. If the board is cut from near the 

 side of a log, few annual rings will show on the surface, their 

 sides will be exposed for wear and will give a grain figure like 

 (A). If the board be cut near the center of the log (B) all the 

 annual rings will show and their edges are exposed for wear which 

 makes the lumber more durable and less liable to sliver up. The 

 former (A) is known as " bastard sawed " and the latter (B) as 

 " rift sawed " lumber. As a log is cut up, the first boards will 

 be bastard grain, then as the center is approached, more and 

 more nearly rift grain, and finally bastard cut after the center is 

 passed. Obviously there are more bastard than rift boards and 

 hence the latter are more expensive, as well as more durable. 



