8 SYSTEMS AND UNITS OF MEASUREMENT 



The standard cord is 4 by 4 by 8 feet, containing 128 cubic feet. There 

 are, however, other cord units in use (Chapter IX) . 



11. Cubic Measure. The cubic volume of trees and logs affords 

 the only basis of accurate and permanent scientific records, and a uni- 

 form standard of measurement. For this purpose the cubic foot should 

 be used as the standard unit. 



Where cubic volume was employed by lumbermen, other cubic 

 units, whose contents were based on cylinders of given sizes, have been 

 adopted arbitrarily. These units possess no advantages over the cubic 

 foot (Chapter IV). 



In most regions, the desire to express the contents of logs in terms of 

 sawed lumber prevented the adoption of the cubic foot as the standard 

 of measurement for log's. 



12. Board Measure. Board measure may be defined as a cubic 

 standard for measuring sawed lumber. A board foot is a board 1 foot 

 square and 1 inch thick. Twelve board feet of sawed lumber equal 1 

 cubic foot. The board-foot contents of sawed lumber is found by 

 multiplying the product of the width and thickness in inches by the 

 length in feet and dividing by 12. 



13. Log rules. A log rule is a table giving the contents of logs of 

 different diameters and lengths. The unit of volume used may be 

 based on cubic measure, or board feet. The latter form of table differs 

 from that based on cubic contents since it indicates only the net volume 

 of the product in boards which result from sawing the log. The use of 

 such log rules is to measure the contents in the log before sawing, as 

 a basis of sale of logs or for other purposes requiring such measurement. 

 Fixed or arbitrary values are assigned or agreed upon for logs of each 

 diameter and length. The table thus becomes a standard of measure- 

 ment based upon a unit of volume. 



This method of measuring logs has consequently led to the develop- 

 ment of numerous log rules whose construction is discussed in Chapters 

 IV, V and VI. These rules differ, some of them greatly, for logs of 

 the same dimensions. 



To secure the universal adoption of a single log rule which is at once 

 accurate and acceptable is probably an impossible task, and several of 

 the more widely used ones will no doubt continue as standards. 



14. Measurement of Standing Timber, Postponed till after Manu- 

 facture. This lack of standardization as to units for board-foot contents 

 of logs inevitably reacts upon the accuracy and consistency of measure- 

 ments of the board-foot contents of standing timber. The contents 

 of a given stand will vary widely with the log rule used in estimating. 



The custom of estimating standing timber in terms of the product 

 is not confined to measurement by board-foot log rules. Hewn ties, 



