Graded Volume Tables. II 



defects offset the volume of lumber sawn from the logs. This is 

 done by dividing the logs into four groups. In group I. are put 

 those in which the defect has decreased the volume of the log 

 io% or less from the volume of a straight and sound log of 

 the same dimensions. Group II contains' those logs in which the 

 defect has caused a decrease of 10-20%, group III a decrease 

 of 20-30%. and group IV a decrease of 30% or more. Under 

 the head of "butt defects" are included butt logs in which butt 

 rot, "dote," or some form of decay is present at the butt of the 

 log. In addition to lowering the total board foot contents of 

 the log these defects may, in cases, also lower the grade of what 

 is' actually sawn. In large logs where there are only four or 

 five inches of butt rot, which does not extend more than a few 

 feet from the butt, the effect is slight upon the volume of the 

 log. "Top defects" include all defects due to rot in the top logs, 

 and also defects in the top of butt logs. Top defects are com- 

 monly more serious than butt defects. This is due largely to the 

 fact that butt defects occur, in the majority of cases, near the 

 center of the cross section, and, in addition, to the fact that there 

 is a greater percentage of shorter lengths among top logs, which 

 makes the trimming of bad ends difficult. Under the head 

 of 'crook' are included longs in which there is a sharp bend 

 or twist. Most of the crooked logs are of smaller diameters, 

 and when a crook is present in a large log it does not 

 have a serious effect unless the abnormality is a severe one. 

 Crook influences volume, but has little effect upon grade. Un- 

 der 'sweep' are included curved logs or logs with a gradual 

 bend. As in the case of crook, sweep is confined largely to 

 logs of small diameter. When it occurs in large logs it is not 

 serious unless the defect is pronounced. Under such circum- 

 stances it will affect grade as well as total volume. This is due 

 to the necessity for cutting across the heartwood. 'Knotty' logs 

 which have abnormally large or numerous knots and are al- 

 most exclusively composed of top logs of the smaller diameters. 

 As a rule grade is affected more than volume. 'Seams' affect 

 both volume and grade, due largely to the penetration of rot 

 along these cavities. 'Shake' is rarely found in beech and maple, 

 being confined almost entirely to birch logs of the largest dia- 

 meters. In addition to affecting volume it has a most decided 

 effect upon grade, in some cases almost the entire volume of 



