The Biltmore Stick. 411 



TABLE OF COMPARATIVE MEASUREMENTS WITH BILTMORE 

 STICK, CALIPERS AND DIAMETER TAPE. 



Total Ave. Total Ave. 



Dif. Dif. Dif. Dif. 



Stick Stick Stick Stick 



No. of Total Diain. Inches & & & & 



Forest Trees Stick Cal. Tape Cal. Cal. Tape Tape 



Crater 100 2915 2820 2881 95 .95 34 .34 



Olympic 180 5300 5276 24 .13 



Snoqualmie .. 975 27953 27851 102 .1 



On the Umpqua Forest no test was made in which a large num- 

 ber of trees were measured with both the calipers and Biltmore 

 stick. However, a number of tests made to check the accuracy 

 of the work showed that measurements made with the Biltmore 

 stick of diameters up to about 42 inches fall within the same inch 

 class as those made with calipers. Above this diameter, measure- 

 ments would fall within the same two-inch class. This data was 

 furnished by Mr. E. H. MacDaniels who also says, speaking of 

 the Biltmore stick: "This instrument is thoroughly practicable. 

 An average man can work with a degree of precision in keeping 

 with the object of an ordinary timber estimate, and its con- 

 venience makes it a very desirable substitute for calipers." 



Errors in using the Biltmore stick are due to irregularly shaped 

 trees. The more nearly the bole in cross section approaches a 

 circle the more accurate will be the Biltmore stick readings. 

 This is also true when calipers are used. A varying arm length 

 causes erroneous readings. Errors may be caused by the stick 

 not being straight or by the observer holding it against the tree 

 in some position other than horizontal. Turning the head instead 

 of the eye while making the reading, or having the eye too high 

 or too low are other sources of error. However with care these 

 errors may be practically eliminated and the stick will prove an 

 extremely convenient instrument which will give very satisfactory 

 results. Its convenience and accuracy should bring it into general 

 use wherever careful cruising is being done. 



