Comiueni. 131 



an additional source of variation ; hence rounding off is still more 

 justified. 



The rounding off", to be sure, must be done with judgment and 

 such judgment is in part based on the use to which the figures 

 are to be put, and the character of the measurement involved. 

 If you convert kilometers into miles, it would be foolish to work 

 out a translation to feet ; if tree heights are involved an approxi- 

 mation to say five feet may still be acceptable when timber is in- 

 volved, but if seedling growth is to be investigated the statement 

 may be needed to even fractions of an inch. 



Still more judgment is required when attempting translations 

 of assortments into other assortments, especially into feet board 

 measure, for the foot board measure in itself is an entirely un- 

 certain quantity when applied to the round log, depending on the 

 size of the log and the log scale used. An article in this issue 

 throws interesting light on this phase. Even the German figures, 

 although they appear as definite cubic measure are variable in 

 their meaning, since the standard of classification is variable 

 from State to State, from time to time, and, to some extent, 

 from species to species (taper!). German yield tables state 

 quantities in cubic meter (at 35.336636 cubic feet) per hectare 

 (2.471 14 acres); hence 14.3 will be the factor by which to 

 multiply to make cubic feet per acre. The statement will be 

 either for all wood including brush, or else only for "stout wood" 

 or "timber wood" (derbhols), leaving out the brush with a dia- 

 meter of 7 cm or less, i. e., including all the wood, branches as 

 well,, of more than 2.7559. • -inches. 



Here we may stop to point out that it is of little if any value 

 to set the limit for conversion at anything closer than the round 

 3 inch, for the quarter inch or so less does not approximate the 

 truth any closer than the round figure, as will be readily admit- 

 ted by those who measure diameters by two-inch classes. 



The brushwood per cent., which, of course, in the young age 

 classes is 100 varies with age, species, and site, hence a direct 

 translation from all wood to timber wood is not possible without 

 a brushwood per cent, or else sawlog percent table. 



The "stout" or "timber" wood is by no means log material for 

 mill purposes, but includes cordwood, etc. : it is merely the useful 

 wood, as it would be with us where fuelwood is saleable. Lo- 

 cality also influences the translation! 



