164 Forestry Quarterly. 



In the column marked "Age" (Column "b") the age should be 

 entered as composed of two values, the first expressing the num- 

 ber of years required to grow to the height of that particular 

 section, and the second, the number of annual rings on that section. 



This method of entering the age enables the reader of the 

 form to determine the rate of height-growth very quickly, by 

 simply glancing at columns lettered "b" and "c" respectively. 



The form, it will be noticed, is practically the same as that 

 formerly in use. The method of entering the values under "h," 

 however, is quite diflferent from that generally described in text- 

 books, in this respect, — ^the measurements for all the sections at 

 a corresponding age of the tree fall in the same column. That 

 is, if the tree is 85 years old, showing 80 rings at the stump, the 

 last measured diameter,* representing the size of that section in 

 1914, will fall in column 9, and the size at 80 years of age, in 

 column 8. This is entirely logical, for the measurements of 

 each decade's growth fall in the column bearing the correspond- 

 ing number. The measurement of the odd years, representing 

 an incomplete decade, fall in the last column, instead of in the first 

 column, as was the case in the method formerly used. If the 

 number of annual rings at the top of the first log (Section No. 

 2) is 70, the age at that section will be expressed as "15-I-70," in 

 -column "b," and the last measured diameter will be placed, not 

 in column 7, but in column 9, directly under the corresponding 

 measurement for section i. Similarly, the measurements for the 

 last section, although it shows only 15 annual rings, will be en- 

 tered so that the diameter of the stem at that point in the year 

 1914 will fall in column 9. To find the volume of the tree in 

 the year 1914, the dimensions of the several sections are read 

 directly from column 9, where they appear one under the other 

 in their logical order. There is now no chance of selecting the 

 wrong pairs of values in computing the volumes of the several 

 sections, and no chance for errors in doubling the radii, for di- 

 ameters have been recorded directly. It would appear that one of 

 the great stumbling-blocks to students in computing volumes from 



at the pith (center), counting "48," "49." ''SO." etc., and a mark placed on 

 the even decades, 50, 60, etc. This accomplishes precisely the same result, 

 and obviates the necessity of counting backvi^ard, which may be objection- 

 able to some. 



*Diameters are recorded instead of radii. 



