52 



the usual height of 4j feet off the ground, but there will always be 

 a lower one than this at the level at which the tree has been felled. 



The measurement of the diameters and the counting of the rings 

 are operations which take time, and, will generally be best effected 

 in camp or at home. For this purpose a disk about 1 inch thick 

 should be cut off the lower end of each section, and carried away 

 to be studied at leisure. To prevent mistakes, the serial number 

 of the tree and corresponding section and other necessary informa- 

 tion should be noted on the upper surface of each disk as soon as 

 it has been cut. 



The lowest section serves to determine the age* of the tree, and 

 the other sections the successive ages of the tree at the heights at 

 which they have been cut. On all of them the annual concentric 

 growths should be marked off in groups of 5 or 10, beginning at 

 the circumference. The outer diameter of each such zone (of 5 or 

 10 years' growth, as the case may be) should then be measured, 

 and recorded in the manner shown in the illustration given lower 

 down. The observer should be careful that the 5 or 10-year 

 groups, marked on the several sections, exactly correspond. Thus, 

 for instance, the first groups of all the several sections should con- 

 tain concentric rings of one and the same age ; the rings of the 

 second groups should be exactly 5 or 10 years younger, and so on. 

 To guard against error in forming the groups, extremely broad 

 or extremely narrow rings should be carefully noted and traced 

 through all the sections. 



With the help of the figures obtained from the observations just 

 described, a longitudinal section of the stem can be delineated, 

 showing the whole course of growth. The scale for diameters 

 should be from 10 to 20 times larger than that for heights. Acen- v 

 tral line being drawn to represent the axis of the tree, the lengths 

 of the sections should be marked off on it according to the fixed 

 scale. At each point of division parallel lines at right angles to 

 the axis should then be drawn, and the measured outer diameters 

 of the respective concentric group-zones pricked off on them. The 

 required section of the tree IR completed by joining by a con- 

 tinuous line or curve all the points corresponding to the same age. 



The rapidity of growth in tieight of the tree may be delineated 

 by means of -a curve, as described at page 52 of Part I of 

 Fernandez's Manual of Indian Sylviculture. Distances should be 

 marked off along a horizontal line representing periods of 5 or 10 

 years, as the case may be. At these divisions perpendiculars 



