OUR FORESTS 



19 



wood products. The veneer industry cuts from logs the thin sheets 

 of wood used in the making of baskets, berry boxes, and other con- 

 tainers. High grade veneers are used extensively by the furniture 

 industry, which also employs other forms of wood; and veneers are 

 used to make up plywood, a material that has had increasing usage in 

 recent years. The cooperage industry employs wood in the form of 

 bolts for the manufacture of barrels, kegs, buckets, etc. There are 

 many other industries which manufacture the numerous wooden arti- 

 cles in common use. The products manufactured by primary forest 

 industries have a yearly value of about 2 billion dollars, not including 

 paper and paper products. 



From the forest also comes the raw material used in the manufac- 

 ture of paper and numerous other wood-pulp products. The basis of 

 paper is pulp made from fibers of cellulose, that remarkable material 



Figuee 12. — Lumber seasoning at the mills. 



Felled trees are cut into logs for transportation to the mill, where they are 

 trimmed and cut into boards. After the boards have been edged and trimmed they 

 are sorted and sent to the lumber yard to be piled and seasoned. 



which forms the cell walls of plants. Wood is the most abundant 

 source of commercially used cellulose in the plant world, for more 

 than one-half of its substance is cellulose fiber. 



Four commercial processes of making paper from wood are in general 

 use : three chemical — the sulfite, sulfate, and soda processes ; and one 

 mechanical — the ground-wood process. In each of the chemical proc- 

 esses the chipped wood is cooked with a chemical under steam pressure 

 in a specially designed cooker, or digester. This process removes the 

 portion of the wood known as lignin, which is the material that binds 

 the cellulose fibers together. In the ground-wood process the uncooked 

 wood is ground into a pulp. Each process is adapted to the manufac- 

 ture of certain grades of paper or to the pulping of certain woods, the 



