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 clear advantage 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 in the world. Shipbuilding creates a heavy demand. Some of the leading European nations use it as deck lining for battleships, and except mahogany and teak, it is said to have no equal for that purpose. Its cheapness gives it a decided advantage over those woods.