This manual was developed by a state advisory committee in Idaho to improve and standardize log scaling and provide a reference in training men for the job of log scaling in timber measurement. The content includes: (1) an introduction containing the scope of the manual, a definition and history of scaling, the reasons for scaling, and the responsibilities and qualifications of the scaler, (2) safe practices in log scaling, (3) principles of log scaling containing units of measure, theory and use of the log rule, scaling equipment, log measurements, merchant ability, numbering and lettering of logs, over-run and under-run, records and reports, non-utilization scaling, and check scaling, (4) identification of tree species, (5) log defects and determination of deductions, (6) scaling from the stump, (7) measurement of post, mining timber, poles, pulp, and log decks, and (8) log grading. There are thirteen tables and 112 illustrations some in color, supplementing the printed text. (DM)