PHYSICAL QUALITIES: Heavy (8th in this list); 50 lbs. per cu. ft.; sp. gr., 0.7470; strong (23d in this list); elastic (32d in this list); hard (13th in this list); shrinkage, from 4 to 10 per cent.; warps and checks considerably, unless carefully seasoned; very durable, hard to work; splits somewhat hard, very difficult to nail.
COMMON USES: Interior finish, furniture, construction, ship building, farm implements, cabinet making.
REMARKS: The most important of American oaks.
[Illustration: Radial Section, life size.]
[Illustration: Cross-section, magnified 37-1/2 diameters.]
[Illustration: Tangential Section, life size.]
CORK ELM. ROCK ELM. HICKORY ELM. WHITE ELM. CLIFF ELM.
_Ulmus thomasi_ Sargent. _Ulmus racemosa_ Thomas.
_Ulmus_, the classical Latin name; _racemosa_, refers to racemes of flowers.
HABITAT: (See map); best in Ontario and southern Michigan.
CHARACTERISTICS OF THE TREE: Height, 80'-100'; diameter, 2'-3', trunk often clear for 60'; bark, gray tinged with red, corky, irregular projections, give shaggy appearance; leaves, obovate, doubly serrate, 3"-4" long; fruit, pubescent, samaras.
APPEARANCE OF WOOD: Color, light brown or red; sap-wood yellowish; ring-porous; rings, marked with one or two rows of small open ducts; grain, interlaced; rays, numerous, obscure.
PHYSICAL QUALITIES: Heavy (15th in this list); 45 lbs. per cu. ft.; sp. gr., 0.7263; very strong (13th in this list); elastic (22d in this list); hard (15th in this list); shrinkage, 5 per cent.; warps, ........; very durable; hard to work; splits and nails with difficulty.
COMMON USES: Hubs, agricultural implements, sills, bridge timbers.
[Illustration: Radial Section, life size.]
[Illustration: Cross-section, magnified 37-1/2 diameters.]
[Illustration: Tangential Section, life size.]
Water, because it flourishes on river banks.
HABITAT: (See map); best northward on river bottoms.
CHARACTERISTICS OF THE TREE: Height, 90', even 120'; diameter, 3'-8'; trunk, usually divides at 30'-40' from ground into upright branches, making triangular outline; bark, ashy gray, deep longitudinal fissures, broad ridges; leaves, 4"-6" long, oblique obovate, doubly serrate, smooth one way; fruit, small, roundish, flat, smooth, samaras.