INSTRUMENTAL HELPS 



163 



and the Biltmore Stick. This last is in construction a 

 wooden bar of about the dimensions of an ordinary scale 

 rule; in use it is held horizontal, tangent to the tree being 

 measured, and at the natural (but a constant) distance 

 from the eye of the observer. Then, one end of the stick 

 being aligned with one side of the tree, where the line of 

 sight to the other side cuts the stick it is graduated for the 

 given diameter. 1 Both instruments have proved service- 

 able on the Pacific Coast, where the timber is so large that 

 a caliper is cumbersome, and because of their portability 

 they have a field of use elsewhere. They are not, however, 

 as quickly manipulated as the caliper hi steady work on 

 timber of ordinary dimensions. 



] 



TREE CALIPER 



2. COUNTER OR TALLYING MACHINE. TIMBER SCRIBE. 

 BARK BLAZER 



These simple little instruments, the last of which can 

 be home-made if necessary, are very serviceable in forest 

 work, particularly in timber estimating. 



3. THE DENDROMETER 



The dendrometer is an instrument for measuring the 

 diameter of a tree at a considerable distance above the 

 ground. There are several forms of this instrument, 

 most of them costly and complicated, that are employed 

 in scientific investigation. With these the practical woods- 



1 See Appendix on theory and accuracy of this instrument. 



