, 
BOARD MEASURE. 13 
In. continental Europe and the Philippine Islands the cubic 
meter has been established as the standard unit for measuring logs 
and timber. 
BOARD MEASURE. 
Board measure is designed primarily for the measurement of ‘ 
sawed lumber. The unit is the board foot. which is a board 1 
inch thick and 1 foot square, so that with inch boards the content 
in board measure is the same as the number of square feet of sur- 
face; with lumber of other thicknesses the content is expressed 
in terms of inch boards. 
In recent years board measure has been used as a unit of volume 
for logs. When so applied the measure does not show the entire 
content of the log, but the quantity of lumber which, it is estimated, 
may be manufactured from it. The number of board feet in any 
given log is determined from a table that shows the estimated 
number which can be taken out from logs of different diameters 
and lengths. Such a table is called a log scale or log rule, and is 
compiled by reducing the dimensions of perfect logs of different 
sizes, to allow for waste in manufacture, and then ne 
the number of inch boards which remain. 
The amount of lumber which can be cut from logs of a given 
size is not uniform, because the factors which determine the © 
amount of waste vary under different circumstances, such as the 
thickness of the saw, the thickness of the boards, the width of 
the smallest board which may be utilized, the skill of the sawyer, 
the efficiency of the machinery, the defects in the log, the amount 
of taper, and the shrinkage. This lack of uniformity has led to 
wide differences of opinion as to how log rules should be con- 
structed. There have been many attempts to devise a log rule 
which can be used as a standard, but none of them will meet all 
conditions. The rules in existence have been so unsatisfactory that 
constant attempts have been made to improve upon them. Asa 
result there are now actually in use in the United States 40 or 50 
different log rules, whose results differ in some cases as much as 
120 per cent for 20-inch to 30-inch logs and 600 per cent for 
6-inch logs. Some of these are constructed from mathematical 
aSee Constantine and Cumberland River log rules in comparison table, 
pp. 16-19. 
