156 FORESTS AND MANKIND 



hundred and fifty thousand people and its annual output is 

 valued at nine hundred million dollars. The amount of wood 

 used is enormous. One Sunday edition of a big city newspaper, 

 alone, requires the timber on eighty acres of forest an area 

 of more than five city blocks all this to produce one edition 

 of a newspaper. 



There are several methods of making paper from wood and 

 a number of grades of paper are now produced. The differences 

 are not fundamental. All of them are directed to utilizing the 

 wood fibers in trees and treating them in such a way that they 

 will mat together into a tough smooth surface. That is essen- 

 tially all paper is a mass of entangled fibers of wood pressed 

 flat and in some cases bleached and given a glossy surface. 



When the wood arrives at the paper mill it is cut into two foot 

 bolts and held against rapidly revolving knives until the bark 

 is cut away. Low grade paper, such as we use for newspaper, 

 is made up largely from wood fibers that have been ground 

 fine, by placing these bolts of wood against a revolving stone. 

 For higher grade paper the bolt is next chopped into small 

 pieces and cooked in certain chemicals to separate the fibers 

 and dissolve out substances in the wood that are not desired 

 in the finished product. Under this treatment the wood be- 

 comes a pulpy mass, called wood pulp, and is either dried and 

 stored for future use in thick, rough sheets or is run through 

 a beater where the pulp is thoroughly mixed until it reaches 

 uniform consistency and where clay and other substances are 

 often added to give body and gloss. The pulp, still in a liquid 

 stage, passes over screens which draw away the water, then 

 on to presses which press flat the fibers in the pulp and remove 

 most of the remaining moisture. Heated rolls, over which the 



