character, but are nevertheless the early or first stage of incipient decay, and will be found less able to resist the action of water than the wood of the same log which is untainted. Although these spots can hardly be reckoned as defects, seeing that they do not penetrate deeply enough to affect in any appreciable degree the value of the timber, the surveyor would do well not to employ such logs in architectural works where it would be difficult to replace the piece should it at any time be found to be decayed.
A swelling upon the exterior of a tree is generally a sign of some defect being hidden beneath; it may be confined to the alburnum, but it may also conceal a serious fault that would be highly detrimental to its value.
The excrescence should, therefore, be removed as soon as the tree is felled, in order to clear up the existing doubt. There are, however, some few exceptions to this; for instance, the burrs which are found upon the Oaks of some districts,[1] and the Austrian and Turkey Walnut tree burrs, which are very finely mottled and figured, make good veneers, and have of themselves a special value for cabinet purposes.
The removal of a branch of moderate size from a tree, close down upon the stem, will generally be concealed by a swelling of the kind first mentioned, particularly if it has been done while the tree was in a healthy state and annually forming new wood. Such hidden knots are frequently in a state of incipient
- ↑ These peculiar excrescences are supposed to be caused by puncturations of the bark by insects, while the tree is growing; but, so far as I am aware, the quality of the trunk of the tree is not often affected by it.—Vide Description of the Walnut Tree, page 111.
