The Identification of Aircraft Timbers: The Use of Timber in Aircraft is Still Considerable and These Notes Have Been Prepared With a View to Assisting the Inspector to Recognize the Usual Varieties Available to Purchase

EXAMINATION of the cross‐section of a tree‐trunk shows the following details of structure: Covering the trunk is the corky bark, the outer layers of which serve to protect the trunk from extreme variations of temperature and humidity, and from mechanical injury; the inner layers, called the bast, serve to conduct the food manufactured by the leaves to actively‐growing parts of the wood and to places of food‐storage in the tree. The bark and the bast together form the rind.