590 Forestry Quarterly. 



and divided by the total number of trees in that class. These 

 average volumes were then plotted and curves drawn from which 

 the values given in the tables were taken. Total heights were 

 averaged and plotted in the same way and final values taken from 

 the curves. 



These tables give merchantable lengths according to local 

 practice, merchantable volumes and total heights corresponding; 

 average volumes and average heights corresponding to diameters 

 breast high. 



I am indebted to Mr. E. H. Roberts for field measurements and 

 help in the calculations and to Mr, R. H. Stephenson for some of 

 the computations. 



"Height of Trees in feet" means that no tree whose volume is given 

 under the figures had a total height from ground to tip of over the 

 larger or under the smaller figure in the heading. 



"Merchantable Length (feet)" means that no tree had a merchantable 

 length more or less than number of feet in heading. 



The Quebec log rule for small sizes as here involved is almost iden- 

 tical with the Scribner rule ; if anything a little more favorable. 



WHITE SPRUCE, Picea Canadensis. 



St. Maurice Valley, Quebec. 



Volume in Cubic Feet, Merchantable, without Bark. 



Average Stump Height 25" ; Diameter of Top inside Bark 4". 

 y^" to ^"=1" class. 



Total Height of Trees (Feet) 



51-61 60-66 71-80 82-91 95-100 97 

 Merchantable Length (Feet) 



54 67.5 81 94.5 Aver. Aver. Basis 



Cu. Ft. Height Trees 



6.00 53.3 6 



9.08 62.5 18 



15.18 12.54 65.8 25 



18.72 16.39 67.5 47 



22.25 23.66 20.48 69.5 72 



25.96 29.84 24.65 71.3 76 



28.78 34.96 28.46 73.6 43 



31-85 39-55 33-20 75.8 43 



36.44 43-82 39.02 76.5 30 



40.86 49.44 44.85 76.6 25 



44.85 53.96 50.96 77.5 19 



49.09 59-61 69.75 57-21 78.5 18 



54.74 66.92 77.55 63.92 79.5 7 



73.28 85.46 73.28 90.6 4 



93.41 89.52 96.0 2 



loi.io 102.76 100. 2 



108.94 III -77 100. I 



116.54 119-01 115-05 99-0 I 



124.69 117.84 97.0 2 



