90 The yo7irnal of Forestry. 



speaking, such a side will be 28-21 inches, and the area consequent 

 on it 795-8041 square inches, a difference already obtained of 170-8041 

 square inches. Let us next suppose that the piece of timber is 40 

 feet in length, then the contents will, if we take the side first given, 

 be 173| J cubic feet ; but if we take the other, they will be 221-056G94 

 cubic feet; or we may say approximately, 221^8 cubic feet. They 

 are found to be more by 47| cubic feet (or fully 26 per cent.) than 

 they were as given by the ordinary measurement. Suppose 

 further that this oak timber be valued at 2s. the foot, a loss 

 of £4 15s. 105d. will then be sustained by the seller on that tree 

 alone. Suppose again that an acre of such oak timber be taken 

 down, containing 50 trees which average these dimensions (I make 

 the figures high that we may read the principle in large letters), there 

 will then be a total loss to the seller of £239 14s. 5id. per acre of 

 such. 



A similar result is obtained by estimating the area of a circular end in 

 any of the other ways above alluded to. There is but little difference 

 between them; but they all agree in differing greatly from all the results 

 given by the quarter-girth method. By any of them we find that a 

 piece of timber so measured may be made to contain about 26 per 

 cent, more timber than we now estimate it at ; that is to say, we 

 must add somewhat more than one-fourth of what we have already 

 measured, and somewhat less than one-third — we might put it at 

 y\ or f to make the result an approximation to the truth. 



Nor is this all, A tree will measure, we know, less or more accord- 

 ingly as it is measured in one or in several pieces. Mr. Hoppus shows 

 in the introduction to his " Tables," that nearly one-sixth as much' 

 again may be gained if we measure a tree in three pieces instead of in 

 one. If, therefore, a purchaser has bought a tree measured in one 

 1 iece be can sell it himself at exactly the same price per foot, and yet 

 realize one-sixth, or more than sixteen per cent, as much again, simply 

 by cutting the tree into three parts. The same purchaser will also, if 

 our remarks are true, have discovered on squaring the tree that he 

 will have gained twenty-six per cent, of timber (though it may not be 

 useful timber) by the inexact method used by the seller of squaring 

 the circle. Putting the two together, therefore, he will have gained on 

 the whole forty-two per cent., or nearly half as much again as had been 

 measured to him of timber — a useful and an important consideration, 



I must be understood here to have been speaking of cases where 

 trees are either measured with the bark of!', or when a deduction has 

 been made from their contents for bark. For if we measure the trees 

 with the bark on, and make no deduction for the latter, then the 

 quarter-girth measure does indeed form a tolerable approximation to 

 the results given by mathematicians ; and we may for practical p-ur- 



