PHYSICAL QUALITIES: Weight, light (53d in this list); 26 lbs. per cu. ft.; sp. gr. 0.4239; medium strong (44th in this list); elasticity, medium (40th in this list); soft (51st in this list); shrinkage, 3 per cent.; warps and checks badly; not durable; difficult to work, splintery, brittle; splits easily, holds nails well. COMMON USES: Coarse, cheap lumber, as joists, rafters, plank walks and laths. REMARKS: The poorest lumber. Bark chief source of tanning material. [Illustration: Radial Section, life size.] [Illustration: Cross-section, magnified 37-1/2 diameters.] [Illustration: Tangential Section, life size.] 18 WESTERN HEMLOCK. BLACK HEMLOCK. _Tsuga heterophylla_ (Rafinesque) Sargent. _Tsuga_, the Japanese name latinized; _heterophylla_ refers to two kinds of leaves. [Illustration: Habitat.] HABITAT: (See map); best on coast of Washington and Oregon. [Illustration: Leaf.] CHARACTERISTICS OF THE TREE: Height, 150'-200'; diameter, 6'-10'; branches, pendent, slender; bark, reddish gray, deep, longitudinal fissures between, broad, oblique, flat ridges; leaves, dark green, two-ranked; cones, small, like Eastern Hemlock. APPEARANCE OF WOOD: Color, pale brown, sap-wood thin, whitish; non-porous; rings, narrow, summer wood thin but distinct; grain, straight, close; rays, numerous, prominent; non-resinous. PHYSICAL QUALITIES: Light in weight, strong, elastic, hard;[A] shrinkage, 3 per cent.; warps ..........; durable, more so than other American hemlocks; easier to work than eastern variety; splits badly. COMMON USES: Lumber for construction. REMARKS: Coming to be recognized as a valuable lumber tree. [Illustration: Radial Section, life size.] [Illustration: Cross-section, magnified 37-1/2 diameters.] [Illustration: Tangential Section, life size.] [Footnote A: Not in Jesup Collection.] 19 DOUGLAS SPRUCE. OREGON PINE. RED FIR. DOUGLAS FIR. _Pseudotsuga mucronata_ (Rafinesque) Sudworth. _Pseudotsuga taxifolia_ (Lambert) Britton. _Pseudotsuga_ means false hemlock; _mucronata_ refers to abrupt short point of leaf; _taxifolia_ means yew leaf. [Illustration: Habitat.] HABITAT: (See map); best in Puget Sound region. [Illustration: Leaf.] CHARACTERISTICS OF THE TREE: Height, 175'-300'; diameter, 3'-5', sometimes 10'; branches high, leaving clean trunk; bark, rough, gray, great broad-rounded ridges, often appears braided; leaves, radiating from stem; cones, 2"-4" long. APPEARANCE OF WOOD: Color, light red to yellow, sap-wood white; non-porous; rings, dark colored, conspicuous, very pronounced summer wood; grain, straight, coarse; rays, numerous, obscure; resinous. PHYSICAL QUALITIES: Weight, medium (41st in this list); 32 lbs. per cu. ft, sp. gr. 0.5157; strong (21st in this list); very elastic (10th in this list); medium hard (45th in this list); shrinkage, 3 per cent. or 4 per cent.;, warps ...............; durable; difficult to work, flinty, splits readily.