Forest Mensuration 7 



The "Biltmore Measuring Stick" can be well used in timber cruising. 

 It requires the exact adjustment of distance between eye and fist of ob- 

 server (usually 26 inches), and gives directly the diameter at the point 

 of the stick where the sight line passes the tree tangentially. The stick 

 is held horizontally against the tree. 



26-iNCH BILTMORE MEASURING STICK. 



Mr. Snead recommends to measure the circumference outside the bark 

 at the big end and to divide the result by 4. He claims that the quotient 

 yields the diameter at the small end inside bark in such a way as to offset 

 mistakes made by Doyle, who under-estimates small logs and over-esti- 

 mates big logs. Snead's suggestion is good, provided, that the cross sec- 

 tion of the log is fairly circular, and that the difference between the small 

 diameter inside bark at the small end and the big diameter outside bark 

 at the big end, amounts to about 7 inches. 



Diameter at small end 



Contents of 16 foot logs, in feet b.m. 



The multiples of sectional area (derived from the diameter in inches, 

 but expressed in square feet) by length of log are readily obtained from 

 cylinder tables published by various authors. The log scale or log rule 

 used by the lumbermen (Lufkin rule) gives at a glance the contents of 

 logs 8 to 20 feet long, according to their diameter. 



