

SO THE WOODSMAN S HANDBOOK. 
Cubic Contents of Logs Without Slabs. 
The two rules in use for determining the amount of square tim- 
ber contained in round logs ar2 the Two-thirds Rule and the 
Inscribed Square Rule. 
THE TWO-THIRDS RULE. 
The diameter of the log is taken at its middle point or the diam- 
eters of the two ends of the log are averaged. The diameter of 
the log is reduced one-third to allow for slab and the remaining 
two-thirds is taken as the width of the square piece which may 
be hewn or sawn out of the log. The cubic contents of the 
squared log are then obtained by squaring this width and multi- 
plying by the length of the log. 
This rule gives smaller results than the Inscribed Square Rule, 
which shows the contents of a square piece that may be exactly 
inscribed in a cylinder of the same diameter as the log. In sup- 
port of the Two-thirds Rule it is claimed that there is a certain 
amount of waste, due to the fact that logs are seldom perfectly 
round and straight, and that the rule makes approximately the 
correct allowance for such irregularities. 
The Two-thirds Rule is sometimes called the Big Sandy Cube 
Rule. Ak 
