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SEASONING OF WOOD

SECTION I

TIMBER

Characteristics and Properties

Timber was probably one of the earliest, if not the earliest, of
materials used by man for constructional purposes. With it he built
for himself a shelter from the elements; it provided him with fuel and
oft-times food, and the tree cut down and let across a stream formed
the first bridge. From it, too, he made his "dug-out" to travel along
and across the rivers of the district in which he dwelt; so on down
through the ages, for shipbuilding and constructive purposes, timber
has continued to our own time to be one of the most largely used of
nature's products.

Although wood has been in use so long and so universally, there still
exists a remarkable lack of knowledge regarding its nature, not only
among ordinary workmen, but among those who might be expected to know
its properties. Consequently it is often used in a faulty and wasteful
manner. Experience has been almost the only teacher, and
theories--sometimes right, sometimes wrong--rather than well
substantiated facts, lead the workman.

One reason for this imperfect knowledge lies in the fact that wood is
not a homogeneous material, but a complicated structure, and so
variable, that one piece will behave very differently from another,
although cut from the same tree. Not only does the wood of one species
differ from that of another, but the butt cut differs from that of the
top log, the heartwood from the sapwood; the wood of quickly-grown
sapling of the abandoned field, from that of the slowly-grown, old
monarch of the forest. Even the manner in which the tree was cut and
kept influences its behavior and quality. It is therefore extremely
difficult to study the material for the purpose of establishing
general laws.

The experienced woodsman will look for straight-grained, long-fibred
woods, with the absence of disturbing resinous and coloring matter,
knots, etc., and will quickly distinguish the more porous red or black
oaks from the less porous white species, _Quercus alba_. That the
inspection should have regard to defects and unhealthy conditions
(often indicated by color) goes without saying, and such inspection is
usually practised. That knots, even the smallest, are defects, wh