FOREST commissioner's kepout. 169 



The main thino- to notice in the fiaure of this simpeof 



~ ^ trees. Iii- 



tree is the way in which itta{)ei's. The lowest limbs 8cnihig.°° 

 on the tree were thirt} -throe feet from the ground, two feet 

 bclosv the point where the log was topped off. Up to this 

 point the taper of the stem is slow. In the twenty feet from 

 the top of the log down, the increase in diameter indeed is 

 only two inches. Above that point, however, is is seen soon 

 to chano-e. Twenty feet above the loo-cut the stem is 5.5 

 inches smaller than at that point. Al)ove forty-five feet high 

 the tree shrinks at least one and one-half inches every four 

 feet. And this tree is in this respect typical. We may state 

 it as a law holding in general among our forest spruce that at 

 about the lower liml)s a taj)er begins which is markedly 

 stronger than that found below. This fact has important 

 bearing in consideration of a just method of scaling timl:>er. 

 To take the simplest case first, let „ .. , ^ . ■ 



- ' Proportion of contents given 



US take two sets of loos of the sj'ime toy Maine log rule in butt and 

 us t.uie i\M) tjetis vx log.-? oi tne same top logs. Logs lO feet long. 



to[) diameter, one set being butt logs 

 from the trunks of small spruce, the 

 other from the up})cr })oi'tion of trees 

 oflarirer diameter. The little table (a) in V"" °^ ®'""" *'"^;'^f • 



•^^ (b) in lower crown of larger 



herewith given tells the story. The (c) ingh up in crown of large 

 figures for some small logs high up in ^^-iiea. 



large trees are also given. Further, to put the same facts in 

 another form which ]^erhaps will still more clearly bring 

 out the point, for quantities of wood represented by the 

 three u[)pcr of these parallel lines we get the same value 

 from the scale rule. The actual value given by the rule, 



reduced to cubic feet, is given by 



the fourth line, the one ])eneatli. 



The values denoted b}^ these lines 

 relate to logs G inches in diameter "~ 



at the top. Here again we have by 



no means an extreme example. 



The practical effect of this peculiarity of our scale rule must 

 be pointed out. Jt might bethought that it would work well, 

 giving to knotty top logs of strong taper a sufficiently less 



