National Geographic : 1916 Apr
Photograph byMiller PART OF ONE DOUGLAS-FIR TREE The great fir trees of the Northwest furnish a good proportion of the nation's lumber for structural uses. From these huge trunks enormous timbers, free from knots, are secured for bridge-building, derricks, and other engineering work. Planing mills usequantities ofthis lumber, and houses, freight cars, and ships are built of it. This tree would make over four miles of plank an inch thick and afoot wide.