This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
There are two varieties of hemlock, one found in the northern states, from Maine to Minnesota, and along the Alle-ghenies southward to Georgia and Alabama, while the other is found in the west from Washington to California and eastward to Montana. The eastern tree is smaller than the western and its wood is lighter, softer, and generally inferior. The trees are evergreen and bear cones, with flat, blunt needles, and they usually grow alone or in small groups in the midst of forests of other trees.
The timber is of a light, reddish-gray color, fairly durable, but shrinks and checks badly, and is coarse, brittle, and usually cross grained. It is hard to work but will hold nails very well. The wood is sometimes used for cheap framing, and has been used for cheap interior finish, but it is so liable to imperfections, such as windshakes and starshakes, that it is not the best wood to use for these purposes, although the increasing cost of the better woods will no doubt force it into more general use. Hemlock is most frequently used for rough boarding and sheathing.