THE FORESTER. 



Api 



c. For the branches. 



Since the solid cubic contents of the 

 branches were found in connection with 

 the sample trees felled for obtaining the 

 factors of shape, the percentage which the 

 former bear to the stem volume of those 

 trees, within each species, can be readily 

 found. The butt end stem contents should, 

 of course, be added to those of the upper 

 portion before determining the percentage. 

 The percentage having thus, in the present 

 instance, been ascertained to be fifteen, 

 the total for Beech is as follows : 



For the parts a 

 For the parts b 



8602.4 cubic feet. 

 771.4 " " 



For the entire stems 9373.8 cubic feet. 

 For branches, 15 % 1406.0 '' " 



Total 10779.8 cubic feet. 



By dividing by 128, and then by the re- 

 ducing factor .7, the cords may be ob- 

 tained. Thus 10779-8 cubic feet equal 

 120.3 col 'ds. 



How TO SHORTEN THE WORK. 



As a rule, more or less of the detail 

 necessarily included in the explanation of 

 the method can be dispensed with in prac- 

 tice. The forest may be so regular as to 

 have the sizes nearly consecutive and in 

 approximately equal proportions, in which 

 case they may be combined into classes 

 with average heights, or even a general 

 height average may be taken. In the lat- 

 ter case the factors of shape would be 

 likely to show a normal and gradual tran- 

 sition, and could then also be averaged. 

 It may even happen that several species 

 are so nearly alike in their rates of growth 

 that they may be treated as one in the 

 finding of the heights and factors of shape. 

 Moreover, since the ''absolute factor of 

 shape " refers merely to the stem above 

 breast-height and not, as ordinarily, to the 

 whole tree, the estimator, after" a little 

 practice, is able to judge pretty accurately 

 of its value. Sometimes it is no great 

 risk to estimate the factor of shape of a 

 tree outright, without felling it. Ordi- 

 narily, the "absolute factor of shape" 

 tends to lie between .4 and .5, except for 

 very small trees. 



ADVANTAGES OF THE METHOD. 



Its principal merit lies in its adaptabil: 

 to the varying conditions of Americ 

 forests. 



The lower lengths, for instance, can 

 corrected in accordance with the size 

 stump customarily left in this, that, or t 

 other, section of the country. The fact 

 of shape, being confined within compai 

 tively narrow limits, may be read 

 altered to coincide with chanonng- com 



, 



tions of growth. Moreover, the seve 

 parts of the tree can be so separated in t 

 measurement and computation as to in< 

 the special needs of the case. Final 

 there is no reason why the board feet cc 

 tents should not be noted in connecti 

 with the stern volume measurements of t 

 sample trees, thus enabling the estimat 

 to present figures showing both the boa 

 foot supply and the cubic contents tl' 

 constitute the basis for production in t 

 forest. The results in board measti 

 cannot, of course, be expected to be a 

 more accurate by being merely joined 

 the new method than they would be und 

 ordinary circumstances. 



There are two other methods of for< 

 mensuration which could be compared wi 

 that under consideration. The one based 

 the so-called " artificial" factors of sha 

 would be invaluable to us were it not th 

 European forests are entirely different 

 type as well as in composition of specie 

 while the method known as Draudt's r 

 cessitates the felling of a great number 

 sample trees, and is much less elastic th; 

 the one described. 



The method by the " absolute factor 

 shape " is a conservative one. In De 

 mark it has been used extensively and h 

 given entire satisfaction. In the Germ; 

 Beech and Oak forest that supplied t 

 example for this article it proved more a 

 curate than the measurements by "an 

 ficial " factors, which were used to arri 

 at a comparison. To my knowledge it h 

 been tested but twice in America. In bo 

 instances the results were fairly satisfa 

 tory. 



G. FRED SCHWARZ, 

 Washington, D. C. 



