There are three varieties of spruce used for building purposes in the United States. There is very little difference between them, and all three varieties are sold under the common name of spruce.
The White Spruce (Abies alba) is the variety most generally found in the lumber yards of New England. The wood is of a whitish color, light in weight, soft, stiff, moderately strong, contains little resin, has no distinct heartwood and very much resembles white pine. It warps and twists much more than pine, and is on that account not a good wood for posts, girders and truss timbers. It makes excellent floor joist and studding, however, and is more largely used in New England for framing than any other wood, but cannot be obtained in very great lengths or large sizes.
A poorer variety of white spruce is also found in the Rocky Mountains, but is only used locally.
The Black Spruce (Abies nigra) grows principally in Lower Canada and the rougher portions of the Northern States. Its wood has the same appearance as that of the white spruce, the difference in color being only in the bark and leaves. The black spruce is said to produce the largest and best timber.
The Red Spruce (Abies rubra), or Newfoundland red pine, as it is sometimes called, grows in the northeast portions of North America, and furnishes a timber of about the same quality and size as the black spruce.
Hemlock (Abies canadensis). - This is a variety of spruce or fir found all along the northern boundary of the United States and in Canada; trees medium to large size. The wood is of a light reddish-gray color, free from resin ducts, moderately durable, commonly cross grained, rough and splintery, and holds nails firmly. It is used largely in New England for small scantlings and sheathing (or boarding, as it is called there); it is very liable to cup shakes, which greatly injures it for framing timbers.
Another variety of hemlock abounds in the Puget Sound region, where it is sold under the name of "Alaska pine." The tree is larger in size, and the wood is claimed to be heavier and harder than the Eastern variety and of superior quality.