A COMPARATIVE STUDY OF TWO LOG RULES, AS 

 APPLIED TO TIMBER IN CENTRAL NEW YORK. 



By John Bentley, Jr. 



It is a well known fact that there are a great many log rules 

 in use in different parts of the country, and that the values given 

 in these rules vary within wide limits even for logs of the same 

 size. Differences of 25% or more are not uncommon in logs of 

 the smaller diameters, and while the relative differences in logs 

 of large diameter are not so great, the absolute differences are 

 sufficient to cause one to marvel that the same log could by any 

 chance yield such uncertain quantities of lumber. The factors 

 influencing the board foot contents of logs are, of course, numer- 

 ous ; but with sound logs and a definite allowance for saw-kerf, 

 it seems that any log rule constructed on sound principles should 

 be able to stand comparison with the actual mill cut of a num- 

 ber of representative logs. That the same log, when scaled by 

 the Doyle rule should yield only 16 board feet, and when scaled 

 by the Scribner rule should yield 32 board feet seems absurd, 

 and yet these are the figures assigned by these two rules for a 

 log sixteen feet long and 8 inches in diameter. If the differences 

 were fairly constant, one might feel inclined to excuse such dis- 

 crepancies on the ground that saw-kerf and slabs were allowed 

 for in different degrees ; but when one follows these same two 

 rules to a log 48 inches in diameter, and finds the relative posi- 

 tions just reversed, — that by the Doyle rule the log contains 1936 

 board feet, and by the Scribner rule 1728 board feet, it then be- 

 comes obvious that the rules can not both of them be con- 

 structed on sound principles. What are we to do? What, in 

 particular, is the man to do who is not familiar with the in- 

 consistencies of log rules ? Some people may even be buying by 

 one rule and selling by another rule, ignorant of the fact that 

 there may be a difference of from 10 to 20 per cent. 



It has long been the desire of the writer to test the accuracy 

 of the "Universal" Log Rule, devised by Prof A. L. Daniels, 

 of the University of Vermont, and published by him in Bulletin 

 No. 102 of the Vermont Agricultural Experiment Station, in 



