MEASUREMENT OF TIMBER 197 



Beginners, when using a pole, usually underestimate the 

 height. 



Having found the volume of each tree, the volume of the 

 wood is obtained by adding all the volumes together. 



The calculation of the volume of woods by estimating each 

 tree singly is a very difficult piece of work, and any great 

 degree of accuracy can only be obtained by constant practice, 

 and by comparing the estimates continually with the actual 

 measurement when felled. This method should only be 

 adopted where the method to be now described is impossible ; 

 that is, in woods where the trees are of all sizes, and are 

 branched and irregular, as we find the standards over coppice 

 or trees in very open woods of any kind. 



Branch wood is seldom estimated, but if there are very 

 large branches, an estimate may be made of those on one 

 side of the tree. All should not be included, as some are 

 likely to be broken in the fall of the tree. 



For small branches the most satisfactory procedure is to 

 cut a small area and to ascertain the outturn per acre, or this 

 may be obtained from the results of previous fellings. Thus, 

 if an acre of oak wood is cut and gives an outturn of 600 feet 

 of timber, 13 cords of pit- wood, and 9 cords of fuel, it may be 

 assumed that in similar woods the same outturn of pit-wood 

 and fuel will be obtained per acre. 



Measurement of standing woods. 



Wherever woods which have grown up fairly densely, so 

 that all the trees are more or less of the same height and 

 shape, are to be measured, the work can be done far more 

 quickly than by estimating the volume of each tree separately. 

 Nearly all middle-aged plantations, especially of conifers, can 

 be measured as follows. 



The method is based on the proved fact that all trees, in 

 a well-grown fairly dense wood, which have the same diameter 



