25 



Form No 4. — Showing the computing of' growing stock hy arranging the species in 



diameter classes. 



Total contents, 95,834 cubic feet: 415,484 B. M. 













Diameter 



Sample tree. 



1- 



a o 



i.s 



Mi 



!25 



Volun 



each dia 



clas 









Average di- 

 mension. 



Average 

 actual 

 volume. 



« r^^> 



Name 

 of species. 



■^1 



II 



1 



3 



O 



1 



meter 



8. 



Basal 

 area. 



Corre- 

 spond- 

 ing di- 

 ameter. 



Cubic 

 feet. 



B.M. 







Cubic 

 feet. 



B.M. 



Oak 



In. 

 8 



23 



\{'b 



1 





Sq.ft. 



Sq.ft. 



Inches. 













9 

 10 



76 

 87 



33.58 

 47.45 



1 



358 



202. 58 



0.56 



10.1 



16.8 



•CO J 2 



6, 014. 4 



21, 480 





11 

 12 



172 

 43 



113.52 



33.77 



1 

 1 























13 

 14 



97 



115 



89.41 

 122.94 



h 



339 



349. 20 



1.03 



13.7 



30.9 



120 



2 



10, 475. 1 



40, 680 





15 

 16 



84 

 164 



103. 08 

 228. 99 



J 

 1 























17 

 18 



181 

 46 



285. 31 

 81.29 



r 



458 



727. 51 



1.59 



17.1 



47.7 



192 



3 



21, 846. 6 



87, 936 





19 



20 



67 

 88 



131. 92 

 191. 99 



J 























21 

 22 



118 

 78 



283. 83 

 205. 91 



* 



316 



747. 06 



2.36 



20.8 



70.8 



336 



2 



22,372.8 



106, 176 





23 



32 



92.33 



) 























24 

 25 



64 

 85 



201. 06 

 289. 75 



}^ 



149 



480. 81 



3.23 



24.3 



96.9 



480 





14, 438. 1 



71, 520 



Hard maple. 



10 

 11 



26 



75 



14.18 

 49.50 



}i 



101 



63.68 



0.63 



10.7 



18.9 



70 





1, 908. 9 



7,070 





16 

 19 



91 

 21 



127. 06 

 41.35 



)' 



112 



168. 41 



1.50 



16.6 



45.0 



180 





5,040 



20, 160 



Hickory 



12 

 14 



' 63 

 16 



49.48 



17.10 



Y 



79 



66. 58 



0.84 



12.4 



25.5 



90 





2,014 



7,110 



Asli 



16 



17 



56 

 29 



78.19 

 45.71 



Y 



85 



123. 90 



1.46 



16.4 



43.8 



168 





3,723 



14, 280 



Black wal- 

 nut 



21 

 22 



5 



68 



12.03 

 179. 51 



Y 



73 



191. 54 



2.62 



21.9 



78.6 



384 



2 



5, 737. 8 



28, 032 





24 

 25 



11 

 12 



34.56 

 40.91 



Y 



23 



75.47 



3.28 



24.5 



98.4 



480 



1 



2, 263. 2 



11, 040 



The black walnut in the blank Is divided into two diameter classes to 

 maintain the uniformity of the diameter classification adopted for our 

 hard-wood grove; otherwise all the trees of the black walnut could 

 have been included in one diameter class. 



DETERMININO VOLUME BY FBLLINa AND MEASURING A PROPOR- 

 TIONAL NUMBER OF SAMPLE TREES FOR EACH DIAMETER. 



Still greater accuracy of result can be obtained if instead of choos- 

 ing at haphazard a number of sample trees of each diameter class, a 

 definite proportion of the trees of each class or of each diameter is 

 used for the computation. For instance, we may decide to measure 1 

 per cent of the trees of each diameter. All sizes of timber are then 

 represented by sample trees in the proportion in which they occur in 

 the forest; we have in the sample trees, then, an exact counterpart of 

 the entire growth reduced in proportion. The relation between the 

 volumes of the whole forest and the proportionately reduced forest of 



