Woodworker's Journal 2008-32-5, страница 38

Wood You Like to Know?

Exploring the Structure and Properties of a Complex Material

By Ian Kirby

Because the wood in most workshops exists primarily as lumber, purchased dimensioned and planed, it's easy to forget that each piece originally came from some part of a living tree. Perhaps even less obvious is that the qualities that prompted your

purchase in the first place — color, grain, luster, weight, hardness — are open to explanation, one that begins at the cellular level. In the first article of a two-part series, I will discuss some details of wood anatomy and function knowable only through study by a powerful microscope and relate them to what can be seen by the naked eye and a lOx hand lens.

The Growing Tree: Roots, Trunk, Leaves

A tree has three parts, each with a particular function.

The roots secure the tree in the ground and take in groundwater containing mineral salts from the soil. The trunk transports this solution, called sap, from the roots to the leaves; it stores food; it holds the living cell layers essential to the growth of the tree; and it provides rigidity to the crown — the