46 BULLETIN 348, U. S. DEPARTMENT OF AGRICULTURE. 
color, although it is likely to contain black specks of bark unless L 
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. 
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| 
{ 
Fie. 34.—Lodgepole pine (Pinus contoria). 
White birch (Betula papyrifera) 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- 
