Mill Scale Studies 7 



the grades of lumber obtained from a log. If, for example, a 

 large order for boards of a certain width, say 12 inches, comes 

 into a mill, all logs large enough may be cut into boards of this 

 width, regardless of the fact that certain of these logs might 

 have been made to yield wider, and therefore higher grade stuff. 

 This will not often happen because the loss due to the sacrifice 

 of grade will eventually offset the profit derived from the special 

 order. A special market demand may sometimes also affect the 

 quantitative yield of a log by requiring boards to be cut thinner 

 than usual, thus increasing the waste due to saw-kerf. 



These are great difficulties, but closer examination will show 

 that most of them are not so serious as to render mill scale 

 studies impracticable. It must be remembered that no lumber- 

 ing operation is ideal or perfect. More or less waste occurs 

 everywhere. If, therefore, a study is made in a mill where more 

 than average care is used in handling the lumber, and a sufficient 

 number of trees is followed through the mill, the results ob- 

 tained ought to apply fairly well to the average results of any 

 other mill, where the usual amount of care is exercised to guard 

 against waste. Again, some of the errors that enter are com- 

 pensating, and in the long run rectify each other. For example, 

 an inspector is just as liable to underestimate the grade of a 

 board as to overestimate it. The average height of stump, and 

 length of top left does not vary greatly in different operations. 

 Furthermore, the forester making the measurements can exer- 

 cise his judgment and discard broken trees, or trees which were 

 so carelessly handled that their yield was far below the normal. 



Forestry is not a mathematically accurate science, and fair 

 averages are all that may be expected from forest measurements. 

 Mill scale studies, if made intelligently and carefully, should 

 give such averages. 



Louis Margolin. 



