FORESTRY QUARTERLY 



Vol. VI.] December, 1913. [No. 4. 



A NEW DENDROMETER OR TIMBER SCALE. 

 By Judson F. Clark. 



Every aid to the judgment of the timber cruiser is welcomed 

 by cruisers and owners alike, for at its best timber cruising is far 

 from an exact science. 



There is only one measurement that can be made on standing 

 timber under woods conditions that is at once quickly and ex- 

 actly made, namely the diameter at breast high. But this meas- 

 urement taken by itself is of little value, for different trees of 

 the same kind and having the same diameter at breast high may 

 vary 100% or more in their merchantable contents, according as 

 they taper more or less rapidly in the log portion of the trunk. 



The cruiser sizes up the merchantable length and its top diam- 

 eter to the best of his ability by his eye and on the accuracy of his 

 judgment depends the value of his cruise. It has always been the 

 custom of the best cruisers to check their ocular judgment by 

 the measurement of whatever windfalls they find on the ground 

 and a most excellent practice it is, where there is no better way. 

 But the occasional windfall in the virgin forest is known not to 

 be an accurate index to the form of its neighbors and at best 

 this check is only better than nothing. 



The need for an instrument that would scale the log contents 

 of standing trees as quickly and as easily as if they were felled 

 has led to many attempts at instrument building, but heretofore 

 there has always been some hitch in the practical working out 

 of the problem under woods conditions. In some cases the in- 

 strument was built to be used at a certain distance from the tree 

 to be measured, in other cases the distance could be varied but 

 must always be measured, or the instrument had to stand on the 

 same level as the tree measured, all of which conditions will be 

 readily recognized as fatal limitations for effective work. It 



