120 FOREST COMMISSIONERS REPORT. 



The use of these tables is as follows: Referring to the tally 

 of diameters of the trees on one of the quarter acre plots it is 

 found that there are 5 trees of 14 inch diameter. Referring to 

 the figures for the height of trees of different diameters it is 

 seen that a tree 12 inches through is 60 feet high, and a tree 16 

 inches through is 90 feet high, and that no figure has been taken 

 for 14 inch trees. Assume then that the height of the 14 inch 

 trees is half way between, or 75 feet high, and raise it to 80 

 feet or drop to 70 feet according to the run of the timber. Re- 

 ferring to the volume table for pine it is seen that the figure for 

 the contents of a tree 14 inches in diameter and 80 feet high is 

 243. There are 5 trees of this size, therefore 5 x 243,, or 1,215 

 board feet, is the cut for trees of this size. Proceed in this 

 way for the trees of each size on the plot, and add the total for 

 the board foot estimate of the quarter acre. Each plot should 

 be reckoned separately, and the estimate for the woodlot ob- 

 tained from them in the same way as described in the preced- 

 ing method. 



With the use of instruments for obtaining the height of 

 trees and compass and chain for measuring areas, and well 

 made calipers this method becomes very exact for even inex- 

 perienced hands. As described above a good approximate 

 estimate should be obtained. 



Home Made Calipers. 



To get an accurate measurement of tree diameters a caliper 

 may be made as follows: Take a piece of planed and matched 

 board four feet long. Split it lengthwise, and even off the split 

 edges with the axe or plane. Saw the grooved part into two 

 pieces 1 1-2 feet long. Nail one of these pieces to the side of 

 the long tongued piece at one end, so that it lays across 

 the split edge at right angles to it. Take the remaining grooved 

 pieces and nail them together at right angles, so that the i-foot 

 part lays across the longer piece at the end with its groove 

 toward the lower end of the cross formed. Cut away in this 

 groove a little so as to widen it out and make it slide easily 

 over the tongue. The two parts will then fit together as in 

 diagram and it will not be found necessary to attach the 

 sliding arm as it can be held by the hand during use. By the 

 use of a pocket rule or yard stick the long bar should then be 

 graduated in inches. 



