absolute; form quotient 351 



form classes 60 and 65 which grew in more open positions, and which 

 consequently had poorer stemform and grew, as a rule, less rapidly in 

 height, gave average taper series which agreed very closely with the 

 computed series in all parts of the stem. From the above it would 

 appear as if the stems of white pine and red pine inside bark were built 

 very much like Scotch pine, Norway spruce, and larch in Sweden, 

 providing the absolute form quotient or the form class is the same. 

 Consequently, Jonson's taper and volume tables for the above Scandi- 

 navian species should be applicable to white and red pine, at least in 

 the locality where the sample trees were taken. That there, at any rate, 

 will be nothing but a very small difference is apparent from the results 

 obtained in using Jonson's volume table to ascertain the total cubic 

 content of the felled sample trees and comparing this with the cubic 

 content obtained by computing the volume of the stem below breast 

 height, and of each tenth above d.b.h., according to Smalians' formula. 

 The result is as follows : 



Measured volume, 87 red pine, 537 cubic feet. 



Jonson's tables, 87 red pine, 543.6 cubic feet — Difference, 1 per cent. 



Measured volume, 41 white pine, 215.6 cubic feet. 



Jonson's tables, 41 white pine, 216.9 cubic feet^Difference, 0.6 per cent. 



The difference in the volume of 13 white spruce was 1.8 per cent and 

 in 6 jack pine 2.2 per cent. 



That a somewhat lower figure was obtained from the actual meas- 

 urement is, no doubt, chiefly due to the greater taper in the tops of our 

 sample trees. To ascertain, however, if older trees would not give a 

 still closer result, the volume of 19 lodgepole pine, for which very 

 accurate measurements were available, was obtained from the volume 

 table. The content of the trees was 462 cubic feet by measurement 

 and 465 cubic feet by the volume table, a difference of 0.6 per cent. 



The stem form investigations in the east have so far been carried on 

 only at the Forest Experiment Station of the Dominion Forest Service 

 at Petawawa, Ontario. That such distinct and regular taper curves, 

 which agree remarkably well with Jonson's series, have been obtained 

 for each form class proves to us that for all normal red and white pine, 

 that is, trees where the root swelling does not reach above breast height 

 or which are not of otherwise faulty growth, the Jonson "absolute 

 form quotient" is an excellent expression of taper or stem form. We 

 believe that Jonson's universal volume tables can be used with great 



