Purdue Hardwood Log Grades (5) 



Prime Practically (90 percent) surface clear in one cutting on 



"three visible faces." ^ Must be 16 inches or larger 

 in d.i.b. 



No. 1 At least three-fourths (75 percent) of length on three 



visible faces must be surface clear in one cutting. -^/ 

 Must be at least 14 inches d.i.b. 



No. 2 At least one-half (50 percent) of length on three visible 



faces must be surface clear in one or two cuttings, 

 neither of which is less than 3 feet long. Must be at 

 least 10 inches in d.i.b. 



No. 3. Will not meet No. 2 specifications. 



Tree grading systems suitable for use with hickory have been reported 

 by Campbell {3) and Herrick (5). These systems rely upon the identification 

 of the grades of one or more logs in each tree. 



Campbell's system applies the Forest Service Standard Grades for 

 Factory Logs to the butt log only, and suggests their application to just one 

 predetermined grading face (90° of the tree circumference). The tree 

 grades are designated as "A," "B," and "C/' corresponding with butt log 

 grades of Fl, F2, and F3, respectively (table 8). 



Tree grade, as defined by Herrick, is the unweighted, arithmetic average 

 of the (Purdue) grade numbers of all of the logs in the tree, prime logs being 

 called "zero." Thus a three-log tree containing a prime, a No. 1, and a No. 2 

 grade log would have a tree grade of 1, (0 + 1 + 2 = 3; 3 4-3 = 1). Since the 

 log grades apply to that portion of the tree facing the observer, and are quite 

 simple in definition, the trees may be graded from a single position, if desired. 



2/ The "three visible faces" concept, as introduced by the late James W. 

 Girard and as used in the Purdue log grades, refers to the portion of the tree 

 visible to an observer from one position and includes evidences of protruding 

 defects, such as limb stubs or branches, even though their bases are not visible 

 to the observer. 



3/ A cutting is the length between surface indications of a sound or un- 

 sound defect. 



- 8 



^m 



