APPENDIX. 



13 





■53 

 >3 



sufficient fot ti'i;urii)tj on our coniiuou Maine trees is given for tlie con- 

 venience of any who may wish to use it. 



In tliis connection it will be well to explain ,, ^ „ 



Contents OF Cylinders Four 

 a mode of reckoninj? which, itself a result of Fekt Long with anv Given 



Ions study bv the most accurate methods, iametek. 

 gives us a short cut to approximate results." 

 This is the use of the so-called form number 

 or factor of shape. This is based on the 5$ 

 tree's height and breast diameter. Breast Q.2 

 diameter, or the diameter at about four and 

 one-half feet from the ground, is the standard 

 of diameter measure used by the Germans; 

 it has also been adopted by the United States 

 Division of Forestry, and it will i)e well if 

 all who study trees in this way will adopt 

 the same practice. Diameter four and one- 

 half feet from the ground is easier to take 

 than a stump diameter, and it is also much 

 more reliable and satisfactory. 



On the height and breast diameter of a tree 

 then is based its factor of sliape. Let us sup- 

 pose a cylinder equal in lieight to tlie tree 

 and having a base equal in diameter to the 

 diameter of the tree breast high. Then the 

 factor of shape is tlie percentage of tliis cylin- 

 der which the actual contents of the tree 

 constitutes. Thus the total contents of the 

 tree recently scheduled was 17 cubic feet. 

 Its diameter breast high was 9 1-2 inches and 



its total height G.t feet. A cylinder of those dimensions contains 32 

 cubic feet. Xow as 17 is .5.3 per cent, of 32, the factor of shape of this 

 tree is .53. 



Much might be said on this topic if it were desirable. When bas(Ml on 

 many in'asui'ements, limited as to size, species and conditions, tliis 

 method of reckoning is for general averages a very handy and satisfactory 

 one. Further than to explain it 1 wish to speak of it in only one connec- 

 tion. The factor of shape for small spi-iice trees in our woods, those say 

 up to 12 or 14 inches diameter, and for the young pines also on our second 

 growth lands is near enough for practical purposes .5. That is, if you 

 know the height of a tree and its diameter 4 1-2 feet from the ground, the 

 volume of the tree will be half the contents of a cylinder of the same 

 dimensions. 



Tree volumes for scientific purposes are usually reckoned bark on, but 

 the tree schedules provide data for determining the net wood volume. 

 Here again a rough and ready figur • for our spruce and pine of ordinary 

 sizes is l-R or 10 2-3 per cent. That is, to get the net wood volume of a 

 tree from the volume derived from measures taken outside the bark 1-6 

 must be deducted. 



5.94 



6.31 



6.68 



7.05 



7.47 



7.88 



8.30 



8.73 



9.17 



9.62 



10.08 



10. .56 



11.04 



11.54 



12.05 



12.57 



13.10 



13.64 



14.19 



14.75 



1 5.. 32 



15.90 



16.50 



17.10 



17.72 



18.35 



18.99 



19.63 



