CHAPTER III 

 THE MEASUREMENT OF LOGS. CUBIC CONTENTS 



23. Total versus Merchantable Contents. Logs are measured to 

 determine their total cubic contents with or without bark, or they 

 are scaled for merchantable contents only. The total cubic con- 

 tents is required in scientific studies of volume and growth and for 

 such commercial purposes as make use of the entire volume of the log. 

 The cubic contents is found by measuring the length and the diameter 

 at one or more cross sections and computing the volume of the log as a 

 whole, or by sections, from these measurements. Where the thickness 

 of bark is measured, the difference in volume of the log measured out- 

 side and inside the bark gives the volmne of bark. 



24. Log Lengths. Softwood or coniferous logs are usually cut into 

 even lengths, or nmltiples of 2 feet, and may be any length from 8 feet 

 to over 60 feet, being limited only by the height and upper merchant- 

 able diameter of the tree, the length of material demanded for manu- 

 facture, or the convenience of transporting long versus short logs. 

 Logs, especially hardwoods, are sometimes cut to odd lengths or multi- 

 ples of 1 foot. The standard commercial lengths for softwood logs 

 vary from 10 to 22 feet, and average 16 feet. In hardwoods, log lengths 

 average somewhat shorter, since utilization of shorter lengths is more 

 common. Log lengths are marked off on the felled tree by notching 

 with an axe. It is customaiy to use a wooden measuring stick 8 feet 

 long, and divided into 2-foot lengths.^ 



For exact measurement of length, the steel tape, graduated to feet, 

 and tenths instead of inches, is used. The log length is measured along 

 the surface, which is assumed to equal the length of the axis. For 

 commercial uses, an excess length of from 2 to 6 inches is required as a 

 margin for trimming. For total cubic contents the logs or sections are 

 measured to their actual lengths. 



1 The accidental chopping off of the top of the measuring stick sometimes results 

 in short measurements. In some regions, notably in Southern pine, careless measure- 

 ment of log lengths resulting in excess trimming allowance and odd lengths causes a 

 waste in woods and mill, in trimming to standard sizes, of from 3 to 5 per cent of the 

 total cut. This statement is based on careful measurements covering 14 years' 

 experience in six states with eight different companies. 



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