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.
The fir tree yields timber very similar to spruce, and is often mixed in with spruce in the market. There are two kinds of fir trees, the western fir tree and the eastern fir tree, the first being known as the silver fir and the other as the balsam fir. All of the firs are evergreen, and bear cones which stand erect instead of hanging down. The wood is soft and not strong, being of a much coarser quality than ordinary spruce. It can be used in building work only for the roughest work in the case of the eastern fir, while the western fir is used more extensively but is not as good as spruce.