APPENDIX A 

 A. LUMBER GRADES AND LOG GRADES 



361. Purpose of Log Grades. The most useful purpose of timber estimating 

 and log scaling is to determine the value of the tags and standing timber. This 

 value depends upon the amount or per cent of lumber of different qualities which 

 can be obtained from the logs or timber to be valued. In § 87 it was shown that for 

 this purpose logs are separated into grades, usually three in number, but that the 

 specifications for and value of each log grade depend upon the contents of logs as 

 expressed in grades of lumber, and in resultant average value or price per 1000 board 

 feet. 



352. Grades of Lumber. Wood varies in texture or closeness of grain, difference 

 between heart- and sapwood, uniformity of texture and freedom from knots, number, 

 size, placement and character of knots, and presence of or freedom from various 

 defects which lower the value of the piece by altering its appearance, strength, 

 surface or suitability for the purposes for which it may be used. Pieces which are 

 entirely free from all defects are suitable for the highest uses and possess the greatest 

 value. At the opposite extreme are found pieces with defects so numerous or serious 

 that they are unfitted for any useful purpose, hence possess no market value and are 

 disposed of as refuse to the burner or as fuel. Certain " cull " grades, formerly 

 refuse, are now generally handled as merchantable, but the practice of scaling has 

 not been altered and such grades are still excluded from the scale as unsound. 



The output of a mill in lumber, if separated according to the quality and value 

 of each board, would form an unbroken series from the most perfect pieces descend- 

 ing through an increasing per cent of more and more serious defects until the poorest 

 merchantable boards are passed, and refuse only is left. 



For practical purposes, this series must be separated by arbitrary standards 

 into groups termed lumber grades, so defined that any piece may be assigned by its 

 appearance to its proper classification or grade. These grades are then made the 

 basis of lumber prices and lumber trade. 



The specifications for a grade are intended to define the poorest piece which will 

 be accepted in the grade, thus excluding all lumber whose quality and defects are 

 such as to unfit it for this grade. The average quality of lumber in any grade will 

 therefore be better than the minimum specifications. Lumber which would qualify 

 for a given grade is sometimes included in a lower grade, but this is not in the interest 

 of the seller and tends to destroy the standards of grading. 



353. Basis of Lumber Grades. The requirements of a lumber grade are, that it 

 be generally adopted in a region or for the trade which handles the lumber from this 

 species or region; that it be consistently applied throughout this region; that it be 

 capable of definition and application in grading; and that it conform to the require- 

 ments for certain definite uses of lumber. To use lumber for a given purpose, when 

 it is better than is necessary and is suitable for a higher use, is wasteful, but to admit 



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