Measures and yields of products and residues 



3281 



Then, according to Bruce and Schumacher (1935, p. 160), 5 to 7 board feet can 

 be cut from each cubic foot of cord wood; the ratio depends on the cordwood 

 diameter as follows: 



Board feet (International 

 Diameter at small end '/4 log scale) per cubic foot 



Inches 



6 4.9 



7 5.5 



8 6.0 



9 6.4 

 10 6.7 



In many mills, lumber yield closely approaches International 14-inch log scale. 



Cords to weight. — The weight of a cord of hardwood pulpwood is discussed 

 in a previous subsection, THE POUND. 



Log volume in board feet by various log scales. — Log volumes in terms of 

 one scale can be converted to another by use of previously tabulated board foot 

 scales, values in table 27-104, and the following procedures by Lane and Schnur 

 (1948). 



To convert International volume to Doyle or Scribner, multiply the Interna- 

 tional volume by the percentage (from table 27-104) for the desired scale, log 

 diameter, and length. Example: Given 1 ,000 bd ft, International volume, in 14- 

 inch logs 12 feet long, what is the Doyle volume? 



1,000 (0.77) = 770 bd ft, Doyle volume 



To convert Doyle or Scribner volume to International, divide the Doyle or 

 Scribner volume by the percentages for the given scale, log diameter, and 

 length. Example: Given 1,000 bd ft, Doyle volume, in 16-inch logs 10-feet 

 long, what is the International volume? 



1,000 ^ 0.83 = 1,205 bd ft International 



Doyle volume can be converted to Scribner, or vice versa, by first changing to 

 International and then to the desired scale, using the above procedures. 



Dollar values per unit volume in terms of one scale can be converted to 

 another scale by substituting dollar values for log volumes in the above proce- 

 dures and by dividing where multiplying is indicated and vice versa. Example: 

 Given a number of logs 16 inches in diameter and 12 feet long, worth $100.00 

 per Mbf International scale, what is an equal value by the Doyle scale per Mbf? 



$100.00 ^ 0.82 = $121.95 



Tree volume in board feet by various log scales. — Tree volumes in terms of 

 one log scale can be converted to another log scale by application of the 

 conversion factors given in table 27-105; since values shown are for southern 

 pines, they must be used with caution on hardwood logs differing in taper from 

 southern pine. 



Board feet log scale to board feet lumber scale. — The amount of lumber 

 actually sawn from a log in excess of the log scale is expressed as overrun. 



