Download or read book Photographic Guide of Selected External Defect Indicators and Associated Internal Defects in Yellow Birch written by Everette D. Rast and published by . This book was released on 1991 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: S2To properly classify or grade logs or trees, one must be able to correctly identify indicators and assess the effect of the underlying defect on possible end products. This guide assists the individual in identifying the surface defect indicator and shows the progressive stages of the defect throughout its development for yellow birch. Eleven types of external defect indicators and associated defects that are particularly difficult to evaluate are illustrated and described. S3.