7 



NOTES TO TABLE 4, TABLE 5, TABLE 6, 

 TABLE 7- 



91Y logs were graded and scaled carefully when entering 

 the mill at the loghoist. Then the output of lum'ber grades 

 sawed out of each single log was carefully and separately 

 noted. 



Of course we cannot look inside the logs when grading 

 them, and two logs of apparently even quality may not furnish 

 the same quantity of lumber of the difierent grades. 



However, what we want to find out is the average output 

 from logs of equal diameter and grade, as all our calculations 

 must be based on averages. 



The output in my case consisted mainly of inch stuff. The 

 inspection was rigid and constantly controlled by the fore- 

 man. 



It is a well known fact, that inspection and reinspeotion 

 never tally. The differenoe of the two, depending on the dry- 

 ing process and the method of piling, is so uncertain in its ef- 

 fect on the output that it has been entirely neglected in the 

 following tables. Those who make use of them must allow for 

 that difference according to the circumstances, and following 

 their own judgmenit. 



The logs were arranged in four grades, viz: 



A. Logs free from any defect. 



B. Logs with one or two defects well located. 



C. Logs with three to five defects well located. 



D. Cull logs. 



Accordingly I constructed the following 4 tables, denoted 

 4, 5, 6 and 7, finding out with the aid of graphical interpola- 

 tion, what per cent, of Is and 2s, of common, cull, etc., a log 

 of a given grade and diameter contains. 



The percentage of Is and 2s increases and the percentage 

 of cull lumber decreases with increasing diameter of logs. 



The percentage of common decreases on the whole with in- 

 creasing diameter, except in the case of ouU logs. 



