174 FARM FORESTRY 



formula is the same regardless of the size of the log. Too 

 much allowance is made for small logs and not enough for 

 large logs. Yet this rule is in more general use throughout 

 the country than any other. The mill cut will often overrun 

 the values given by Doyle Rule by 25 per cent. 



The Doyle-Scribner Rule. A combination of the Doyle 

 and Scribner Rules, known as the Doyle-Scribner Rule, is in 

 common use for measuring hardwoods. In this rule the figures 

 of the Doyle Rule are used for small logs under 28 inches 

 in diameter, and above 28 inches the Scribner Rule is used. 

 Since the Doyle Rule gives low results for small logs and 

 the Scribner Rule gives low results for large logs, this rule 

 is evidently unfair to the one selling timber. 



The International Log Rule. Several attempts have been 

 made to construct a standard log rule that will state with fair- 

 ness to both buyer and seller the contents of logs. Such a 

 log rule is the International Rule, which is based on a mathe- 

 matical formula checked by actual experience in sawing out 

 boards from logs. Several log rules will be found in the 

 Appendix. 



Considerable confusion often arises in measuring the con- 

 tents of logs through the use of different log rules by the buyer 

 and seller. The log rule to be used should be specified in the 

 contract to be drawn up for the sale of the timber. 



Scaling Logs. The measuring of logs to find the contents 

 in board feet by means of a log rule is called log scaling. 

 For convenience in the woods the log rule is printed on a 

 wooden stick about 4 feet long, called a scale stick. By means 

 of the scale stick placed across the small end of a log inside 

 the bark the width rounded to the nearest inch is noted. Oppo- 

 site the inch mark will be read in line with the proper length 

 of log the number of board feet or the scale of the log. 



A log rule is constructed to give the contents of perfect 

 logs without crook or other defects. If defects occur in logs 

 the scale as given in the log rule must be discounted to allow 



