50 



measurements of the trees felled on sample area described in Blank 

 Ko. 2. When the calipering is completed and recorded, the measure- 

 ments of growth at the stump and at the top of each log is made by 

 counting and measuring the rings on the average radius of each cross 

 section, as indicated in Blank ^o. 4 of the appendix. The most sys- 

 tematic results are secured if all the trees are cut into logs of equal 

 length, say 16 feet. Each blank of set 'No. 4 is intended for recording 

 the measurements of cross sections from all the trees at approximately 

 the same height from the ground separately for each group : thus one 

 of Blank No. 4 records the results of stump measurements for the trees 

 of each of the three groups (dominant, codominant, and oppressed), 

 while the other records the results of cross section at the top of first 

 log (18 feet from ground), the third, that taken at the top of the second 

 log (34 feet froj^ ground), etc. In the appendix are given two blanks 

 of set No. 4; one records the stump section, the other the cross section 

 taken at the top of the third log (50 feet from the ground). The groups 

 of trees in this particular instance had nine cross sections, which were 

 recorded in nine blanks of set No. 4. The measuring of the cross sec- 

 tions should begin with the stump section, because the number of rings 

 counted on this section determines the age of the tree (of course, the 

 allowance made for the height of the stump must be added), which 

 must be known for establishing age classes before the measurements 

 of sections are registered. Trees either of the same age or differing 

 not more than twenty years for old trees and ten years for younger 

 trees, usuall}^ constitute one age class. The rings of a section are care- 

 fully counted on the average radius, and the distances for 10, 20, 30, 40, 

 etc., rings from the center to the periphery are noted in millimeters. 

 The entire radius is also noted. Besides, for each cross section should 

 be noted — 



(1) Number of tree to which it belongs. 



(2) Exact height from ground. 



(3) Thickness of bark. 



(4) Number and width of rings in the sapwood. 



(5) Number of rings on the cross sections. 



