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 1 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 artt- 
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 
F-201668 
Fiegur® 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 eround- -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 
