22 



volume determined in the way explained on page 16, where the measur- 

 ing of a felled tree is discussed. 



CALCULATION OF THE TOTAL VOLUME OF THE STAXD. 



The volume of the sample tree thus obtained represents in the average 

 all the trees of the species. The total volume, then, of the species may 

 be determined by multiplying the volume of the sample tree by the 

 number of trees of the species contained in the forest. When a spe- 

 cies is represented by a large number of trees it is always advisable to 

 select more than one sample tree and determine separately for each its 

 volume in cubic aod superficial feet. There will be noticed a difference 

 between the volumes of the sample trees notwithstanding their diam- 

 eters and heights are the same; this is due to the difference in the 

 tapering of the sample trees or, in other words, to the difference of the 

 factor of shape, which though small is invariably noticed even among 

 trees of the same dimensions. The average volume of the sample trees, 

 whether in cubic or superficial feet, is then multiplied by the number of 

 trees of the species in the forest, in order to obtain the total volume of 

 the species. For the oak measured and recorded in the above example 

 five sami)le trees of 16.9 inches in diameter at breast height and of the 

 same height were selected in the grove. All of them were felled and 

 sawed into logs. The following are their actual volumes given in cubic 

 and superficial feet : 



Sample tree. 



Cubic 

 feet. 



B.M. 



46.2 



180 



48.3 



204 



44.8 



156 



47.5 i 



192 



42.1 



148 



No. 1. 

 No. 2. 

 No. 3. 

 No. 4. 

 No. 5. 



These five sample trees give in the average 45.8 cubic feet and 17G 

 feet B. M. Multiplying these two averages by 1,620 (number of oaks) 

 the volume of the oak equals: (1) 45.8x1,620= 71,196 cubic feet; 

 (2) 176x1,620 = 285,120 B. M. The same operations and calculations 

 are made for each species of the stand. 



