test, correction for locality is unnecessary. If, on the other 

 hand, the local trees consistently differ from the tabular values, 

 the table should be corrected for local use. 



To prepare a local volume table 6 from the 20 to 25 trees above 

 referred to, percentage relations, averaged for each inch-class 

 represented by the local trees, should be established as between 

 the local and tabular values and curved over diameter. If 

 these relations are not uniform for trees of all height classes, 

 separate curves may be necessary for tall, medium, and short 

 trees. The final smoothed percentages should then be applied 

 to the tabular values, making a new table for local use. 



CORRECTION OF VOLUME TABLES FOR DIFFERENT LIMITS OF UTI- 

 LIZATION. 



The limits of utilization upon which the tables are based do 

 not coincide with actual utilization in all parts of the region. 

 Where they differ, correction of the tabular values is necessary. 



For volumes in cubic ; rds it is sufficient to measure 



the length of a few felled 20 or 25 used in the test just 



described will do very well) to both the limit used in the table 

 and that set up by the conditions of actual utilization. By sub- 

 traction the Lengths of the section to be deducted or added are 

 then obtained, and their volumes calculated in tin 1 proper unit. 

 at with the breast-high diameter of the 

 ribly with their height as well; smoothed values 

 should be obtained by curvinj Corresponding 



made in the regional tables. 

 jo through the more 

 labori( I 3 to both limits and obtaining 



by subtraction the board-foot differenc 



• g board-foot tables in which merchantable heights 



sed in number of 1<>l:> in this way may easily lead to 



errors in their use. £ sample, that the to]) limit for 



calculating board feet by the International rule is S inches 



Qtain four logs to the o-inch 

 top, a ,:• in the regional table here given as 4-log trees, 



drop I 3 3-Iol;: trees to an 8-inch top. It es are 



tallied in * their volumes as taken from 



the revised tables will then be much too low, unless the head- 

 ings for hei This can of con: 

 done, but \ } if relatively small use is to be 

 made of t':. ntinue to tally these trees in 

 the held as 4-Iolz: tree.-— of course, estimating height to a 5-inch 

 top. The unused volume, between the 8-inch and o-incl. 

 can be cared for by a age deduction, as for cull. It is a 



6 A volume ' ig heights, is often 



local volume table; this is not the meaning in the present ins: 





