j^ TIMBER ESTIMATING. 59 



of purchase, and the seller wishes to obtain an adequate return 

 for his material. In case of an ordinary lumbering operation where 

 all merchantable material is taken, the quantity of wood products 

 actually cut, as indicated by the log scale, or by measurement on 

 . the ground of the logs produced, gives a comparison by which the 

 accuracy of an estimate of stajading timber may be judged. 



The first products of the forest are: Logs intended for lumber, 

 poles, ties, or posts, and cord wood. With few exceptions the tim- 

 ber is converted into the product which has the greatest stumpage 

 value or readiest sale, and it should be estimated in terms of this 

 H product — usually saw logs. 



The contents of logs are measured by log rules. No two of the 

 many log rules now in use give equal volumes for logs of identical 

 dimensions, and the extreme variation in the scale of a given lot 

 of logs by different rules may be greater than 20 per cent. And 

 .:_ even by the same rule, logs may be scaled closely or very loosely; 

 liberal allowance may be made for defects or practically no allow- 

 ance at all, according to the training of the scaler or the closeness 

 of utilization. 



The closeness with which the timber is utilized wall vary in a 



given stand. As stumpage values increase, the aim will always be 



- to secure more timber by cutting to smaller diameter, by lower 



- stumps, and by utilizing up to a smaller diameter at the top. 

 Species which were at first considered unmerchantable and later 



■ become valuable must be estimated. Improved transportation 



^'facilities and the introduction of better logging machinery encour- 



9 age the removal of poorer classes of logs formerly unprofitable. 



For these reasons estimates have to be revised to correspond with 



advance in values, and old estimates, even if they were correct 



when made, are usually too small for present market conditions. 



Since there are so many and so various factors influencing the 

 standard of measurement, it is seldom possible to make an estimate 

 of timber which will come closer than within 10 per cent of the 

 actual quantity standing on the ground. Yet an estimate must 

 always be based on the present market conditions, except when 



- the owner plans to hold his timber for an expected improvement in 

 values, and therefore requires an estimate which will include 



. ^ species and sizes not now merchantable. 



