SHADE TREES AND FORESTS 487 



Uses of forests. Forests serve three great purposes: 

 first, they act as a protective covering on the area on which 

 they are growing; second, as a source of wood; and third, 

 as a source of beauty and pleasure. The first kind of forest 

 is called the protective forest ; the second, the supply forest ; 

 and the third, the recreation forest. The first and third 

 uses are served while the trees are still standing, the second 

 use after they are cut down. By proper management, a 

 forest may be made to serve all three of these purposes. 



The value of forests as a source of wood is so evident that 

 it needs very little explanation. To appreciate this, one has 

 but to think of the manifold uses to which wood is put every 

 day. 



LABORATORY EXERCISE 37 



Purpose. To learn to tell the cuts of wood found in chairs 

 and tables. 



Materials. Collections of small samples of wood, showing 

 different sections. Pieces may be obtained from a carpenter's 

 shop, or small branches may be collected from trees. Pieces 

 from one to two inches in diameter and four inches long make 

 satisfactory samples. 



Directions. A. Examine specimens of wood until you find 

 each of the following : 



1. Sapwood and heartwood. How do these two differ? 



2. Annual rings of growth. What differences do you find 



among the different rings in the same piece of wood ? 

 How old is the piece ? 



3. Spring wood and summer wood in the rings. How do 



these differ? 



4. The pores. Find : 



a. A ring-porous wood, in which the pores in the spring 



wood are larger and more numerous than the pores 

 in the summer wood. 



b. A diffuse-porous wood, in which the pores are small 



and equally distributed through all the ring. 



c. A non-porous wood, in which pores are absent. 



