![]() ![]() (This is the version in the DQYDJ tool above) His original tables ranged from 10' - 24' logs, with 12" - 44" diameter (small end, inside bark).Ī number of the tables use the 1942 Bruce and Schumacher Scribner formula estimate (assuming a 16" log): ![]() Scribner based it on estimates off drawings of logs cut using a 1/4" kerf. The Scribner Log Rule was first published in 1846 by J.M Scribner. Fisher bought the rights to Scribner's rule in the mid 1870s and (for whatever reason) published a table of Doyle values in place of Scribner's values in a reissued guide.Įven today, the Doyle rule is the local custom in many areas. However, the Doyle rule regained popularity when George W. Scribner's rule largely replaced it after its publication in 1846. For large logs the allowance is too small. The Doyle Rule gives too much allowance for slabs & edgings in small logs – a pro-buyer characteristic (in small logs, anyway!). (Also see this diagram from Herman Chapman's 1921 Forest Mensuration). The main weakness of the Doyle rule is in its allowances for slabs and edgings. By tradition, it's still even used widely today in many areas as a rough guess of yield. D = Diameter of log in inches, (inside bark) small end of the logĪt one time or another, the Doyle rule was the official log scaling method in a number of states.Even though the Doyle Rule is far and away the most popular all time estimate, no known copies of Doyle's 1825 pocket reckoner exist (although it likely contained the rule). The Doyle Log Rule dates to at least 1837 when Edward Doyle published his initial formula in Rochester, New York. There are many more log rules than are in the tool – see an excellent overview here from Frank Freese of the USDA. You can learn the ins and outs of log measurement and scaling in the National Forest Service's National Forest Log Scaling Handbook. In the tool, I've included four – the Doyle Log Rule, Scribner Log Rule, International 1/4" Kerf Log Rule, and International 1/8" Kerf Log Rule. Still, log scaling methods are the traditional way to price lumber. They aren't ignorant rules, however – while they produce overrun or underrun (where lumber exceeds or comes short of the rule, respectively), they attempt to factor in wastage and limitations. These rules factor in saw kerf, wastage, knots, and shrinkage – but have their limitations due to different species of trees and lack adjustment for tree taper. While electronics and weighting are well and good, traditional log rules are the most common way to estimate usable lumber. ![]()
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