‹‹‹ Vitr. 2.9.5 | Table of Contents | Vitr. 2.9.7 ›››
6First, the fir, containing a considerable quantity of air and fire, and very little water and earth, being constituted of such light elements, is not heavy: hence bound together by its natural hardness it does not easily bend, but keeps its shape in framing. The objection to fir is, that it contains so much heat as to generate and nourish the worm which is very destructive to it. It is moreover very inflammable, because its open pores are so quickly penetrated by fire, that it yields a great flame.
6To begin with fir: it contains a great deal of air and fire with very little moisture and the earthy, so that, as its natural properties are of the lighter class, it is not heavy. Hence, its consistence being naturally stiff, it does not easily bend under the load, and keeps its straightness when used in the framework. But it contains so much heat that it generates and encourages decay, which spoils it; and it also kindles fire quickly because of the air in its body, which is so open that it takes in fire and so gives out a great flame.