the professional estimator. As preliminary to the construction 

 of such tables the contents, in board measure (B. M.), of a great 

 many felled trees should be determined by actual measurement, 

 and classified according to some dimension of the tree. The vol- 

 ume of a tree varies with its diameter and height, and where ex- 

 treme accuracy is desired, volume tables are made to show con- 

 tents of trees of different heights, as well as of different diam- 

 eters; but a classification on the basis of diameter at breast 

 height from the ground will be found most convenient and quite 

 practicable for ordinary purposes in estimating stands of timber. 

 Breast height is uniformly taken to be four and one-half feet 

 from the ground, and the diameter at that point is measured with 

 a pair of tree calipers in inches outside the bark of the standing 

 tree. Transactions for the sale of stumpage are made for the 

 merchantable volume, and that varies with the diameter inside 

 the bark and the length of the salable material in the tree. Scrib- 

 ner's Rule, the legal standard in Minnesota for the measurement 

 of log contents, gives the volumes of logs in board measure ac- 

 cording to the length in feet and the diameter in inches inside 

 the bark at the small end. Now to get a working table we must 

 have one that will give the contents of the standing tree in feet 

 board measure for each diameter size taken outside the bark at 

 breast height (Dbh), and as trees of the same diameter vary 

 greatly in volume we must obtain measurements of as many as 

 possible of each diameter and enter only the average size in the 

 volume table. 



To secure reliable results in the use of the volume tables all 

 the trees in the stand which is to be estimated must be calipered, 

 classified and volumes for each class computed by aid of the 

 table. On account of the time required for the work objection 

 is raised to this method, but experience has shown that the bet- 

 ter results obtained will pay for the additional expense of the 

 estimate. However, an estimator, after some practice with the 

 calipers, will be able to classify the trees on his tally sheet in 

 inch diameter sizes without the aid of the instrument sufficiently 

 accurate for most occasions where time is an essential. 



With the idea of preparing a practical working table for one 

 species I selected the white spruce as being the most important 

 commercial tree in this vicinity and on the particular tract of 

 land for which I wanted an estimate, and proceeded to obtain all 

 measurements possible under the circumstances attending my 



