46 



BULLETIN 343, U. S. DEPARTMENT OF AGRICULTURE. 



color, although it is likely to contain black specks of bark unless 

 knots are removed from the wood before it is ground. The yield was 

 approximately 2,200 pounds per hundred cubic feet of solid rossed 

 wood. 



Fig. 34.— Lodgepole pine (Pinus contorta). 



White birch (Betula papyri/era) yields a pulp in which the fibers 

 are short, though very fine. It is necessary to use a very dull stone 

 in the grinding process, and even then laps crack along the edges 

 when folded. The pulp, moreover, has a decidedly pinkish tinge, but 

 the ground wood could undoubtedly be used as a filler in the produc- 



