Bull Pine (Pinus Ponderosa Douglas). This species of pine is distinct from the other yellow pines in that it is a product of the western part of the United States, being found from the Rocky Mountains westward to the Pacific Ocean. Its distribution is shown by Fig. 314. It is the largest species of pine known, growing to be from one hundred to three hundred feet in height and from six to eight feet in diameter. The bark is thick and deeply furrowed. The wood varies greatly in quality and value, but in general it is heavy, hard, strong, brittle, and rather fine-grained. The medullary rays are numerous but rather obscure; the proportion of sap-wood to heartwood is large, the former being almost white in color and the latter a light red. Since this species contains much sapwood, it is not durable, but is used in exposed places and in contact with the soil by treating it with a preservative. It is manufactured into lumber and is also used for railway ties and fuel. Its weight when seasoned is twenty-nine pounds per cubic foot.

278. The Spruces (Picea) are found in abundance in the United States, and though there are several varieties, they are all divided commercially into two classes, - white spruce and black spruce. Spruce resembles white pine in many of its characteristics and uses; in fact, the resemblance is so great that there is much confusion of names in different localities. It is often very hard to distinguish between black spruce and white spruce.

279. Black Spruce (Picea nigra Link; Picea Mariana Mill.). - This tree grows in a region between Pennsylvania and Minnesota, and along the Allegheny Mountains to North Carolina, but reaches its best development in Canada. It grows to a height of from forty to eighty feet, and a diameter of from one to two feet, usually having a straight, conical-shaped trunk and dark foliage. The wood is light, soft, not strong, straight-grained, and satiny. It contains considerable resin; the medullary rays are few but conspicuous. The heartwood has a light red color which is sometimes nearly white, the sapwood being still whiter. It is used in shipbuilding, and for piles, posts, and railway ties. In fact, in most of its uses it is a somewhat inferior substitute for white pine. The weight of the seasoned wood is twenty-eight pounds per cubic foot.

280. White Spruce (Picea alba Link; Picea Canadensis Mill.) grows in high latitudes and is found in northern United States, Canada, Labrador, and Alaska. Its general characteristics and use are much the same as those of the black spruce, except that the trees grow a little higher and the color of the wood and foliage is somewhat lighter.

281. Hemlock (Tsuga), of which there are two principal species, is light, soft, stiff, brittle, coarse-grained, and inclined to splinter, and the limits of sapwood and heartwood are not well defined. The wood has a reddish gray color, is free from resin ducts, is moderately durable, shrinks and warps considerably, wears rough, and retains nails firmly. The bark, which is red on the outside, is used for tanning leather.

282. Eastern Hemlock (Tsuga Canadensis Carr.) is found in eastern and central Canada, where it has its best development, and extends southward to North Carolina and Tennessee. It is a handsome tree with a straight trunk, and grows to be eighty or more feet in height and two or three feet in diameter.

It is manufactured into coarse lumber and is used in the frames of buildings, for outside finish, and for railway ties. This species furnishes nearly all of the hemlock for the eastern market. The weight of the seasoned wood is twenty-six pounds per cubic foot.

283. Western Hemlock (Tsuga Mertensiana Carr.), growing in the western part of the United States and Canada, and also in Alaska, is similar to eastern hemlock but appears in larger trees, is of a better quality, and is heavier, its weight being about thirty pounds per cubic foot. When treated to prevent decay, it is much used in exposed situations and in contact with the soil, especially for railway ties.

284. Bald Cypress (Taxodium distichum Rich.) is found in Maryland, in the south-Atlantic and Gulf states, through Florida to Texas, and in the Mississippi valley from southern Illinois to the Gulf. It usually grows in swamps and wet places, sometimes forming large forests. The wood is light, soft, close, straight-grained, not strong, resinous, very easily worked, and very durable when in contact with the soil or with water; the medullary rays are numerous but very obscure. It has a color between light and dark brown with nearly white sap-wood. It is manufactured into shingles, and is used for the construction of buildings and for railway ties. Its peculiar durability in contact with water fits it for use also in the manufacture of tanks, casks, and barrels. This wood is a very important one; it is commercially divided into white and black cypress because of differences in hardness due to age and environment. The weight of the seasoned wood is twenty-nine pounds per cubic foot.

285. The Common Redwood (Sequoia sempervirens Endl.), found in the central and northern coast region of California, grows to be from two hundred to three hundred feet in height, and from six to eight, and sometimes to twenty, feet in diameter.

When young it is a graceful tree with straight and tapering trunk and drooping branches, the lower ones sweeping the ground. In old age the trunk rises to a great height bare of boughs, and the branches on the upper part are short and irregular. The wood resembles that of cedar in appearance, the color being a clear, light red, with the sapwood almost white, the proportion of sapwood to heartwood being small. It is light, soft, not strong, very brittle, rather coarse-grained, susceptible of polish, easily worked, and very durable in contact with the soil. The medullary rays are numerous but very obscure. It yields the principal lumber of the Pacific coast and is used for shingles, fence posts, telegraph poles, railway ties, coffins, flumes, tanks for water and for tanning purposes, and water pipes for irrigation. When its grain is curled it forms a good material for interior decoration and cabinet work. The weight of the seasoned wood is twenty-six pounds per cubic foot.

286. The Big-Tree Variety of Redwood (Sequoia gigantea Torr.) is the largest tree of the American forest. It grows in practically the same locality as the common redwood, but appears chiefly in isolated groups, and there are probably only a few hundred individual trees in existence. Some specimens have been measured that were three hundred and twenty feet in height and thirty-five feet in diameter, with bark about two feet thick. The wood resembles that of the common redwood except that it is more brittle. The distribution of the redwoods is shown by Fig. 313.