170 AMERICAN FOREST TREES 



branches. In thick stands the lower limbs die and the trunks remain 

 bare, except an occasional small branch. Douglas fir at its best grows 

 in thick stands, with crowns forming a canopy so dense that sunlight can 

 scarcely reach the ground. The result of this is that other species have 

 little show where Douglas fir prevails. 



The bark of large trunks attains a thickness of eight or ten inches 

 near the base. Young bark contains blisters filled with resin, similar to 

 those of balsam and other species of fir. 



The wood is light red or yellow, the sap much whiter. Lumbermen 

 recognize two kinds of wood, yellow and red. The former is considered 

 more valuable. Both may come from the same trunk, and the reason for 

 the difference in color and quality is not well understood. It cannot be 

 attributed to soil or climate, or to the age of the tree, and it does not 

 seem to depend upon rate of growth. The bands of summerwood are 

 broad and quite distinct. A few scattered resin ducts are visible under 

 a magnifying glass of low power. The medullary rays are numerous, 

 rather large, frequently yellow, conspicuous when wood is split radially. 

 The wood's average weight is given by Sargent at 32. 14 pounds per cubic 

 foot, yet some specimens exceed forty pounds. It is hard, strong, and stiff. 

 In mechanical properties it rates about the same as longleaf pine of the 

 South. Elaborate tests have been made to determine which of these 

 woods is the better for heavy construction, and neither appears to win 

 over the other. In one respect, however, Douglas fir has a dear ad- 

 vantage over its southern rival: it may be had in much larger pieces. 

 No other commercial wood of the world equals it in that particular. The 

 Douglas fir flagstaff at the Kew gardens in England was 159 feet long, 

 eight inches in diameter at the top, more than three feet at the base. The 

 extraordinary size of squared beams cut from this species has led to 

 great demand for it for heavy construction in Europe and this country. 

 The pines from the Baltic sea region of northern Europe, which held 

 undisputed place in heavy work during centuries, has now yielded that 

 place to Douglas fir and longleaf pine. 



No other single species in the United States or in the world equals 

 the annual sawmill cut of Douglas fir. The four species of southern 

 yellow pines, if counted as one, surpass it; but singly, not one comes up 

 to it. In 1910 the lumber cut from this fir amounted to 5,203,644,000 

 feet, which exceeded one-eighth of the total lumber cut in the United 

 States. The importance of such a timber tree can scarcely be estimated. 

 The available supply in the western forests is very large and will last 

 many years, even if the demand for more than 5,000,000,000 feet a 

 year continues to be met. 



The timber is exported to practically every civilized nation hi the 



