CHAPTER V 

 THE MEASUREMENT OF LOGS— BOARD-FOOT CONTENTS 



40. Necessity for Board-foot Log Rules. In other lines of industry 

 it is not customary to measure raw materials in terms of the quantity of 

 finished product contained therein. The volume or weight of the raw 

 product is the basis of sale. On this basis logs would be sold for their 

 cubic contents. 



But the purchaser of raw material must know approximately the 

 quantity of finished product he can obtain from it before he can estimate 

 its value. If the product is to be lumber, the possible yield of boards 

 of certain qualities and grades determines for him the value of the logs. 



If it had been found by experience that all logs regardless of size 

 would yield the same per cent of their contents in lumber, if sawed by the 

 same methods, the cubic standard might have been universally accepted, 

 as it was in the Adirondack region. But when it developed that there 

 was no consistent ratio of cubic to board feet the only alternative was 

 to measure the product directly as boards. 



That the board-foot log rule was needed is shown by the fact that such 

 rules were originated independently in practically every lumbering 

 region. The contents of the log in sawed 1-inch boards was placed on 

 the scale stick, separately for each inch-class and each standard length. 

 These board-foot rules soon became practically the universal standard 

 of log measure, and are only recently being superseded where the logs 

 are used for other purposes than lumber; they will continue to be a 

 generally accepted commercial standard of log measure for the lumber 

 industry as a whole, until such time as the original stands of timber of 

 the country give way to smaller second-growth and closer utilization 

 and probably as long as a large percentage of logs are sawed into lumber. 



41. Relation of Diameter of Log to Per Cent of Utilization in Sawed 

 Lumber. The sawed output from logs in board feet shows an increasing 

 per cent of utilization with increasing diameter of the logs. This result 

 may be expressed by the ratio of board feet produced from each cubic 

 foot of total volume. This tendency is illustrated in Table III. 



The per cent of utilization in this table is based on the total cubic 

 contents of the log as measured by Huber's formula at middle diameter 

 inside bark. But practically all log rules for board feet base the con- 

 tents upon the cylinder whose diameter is taken at the small end, in 



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