326 INSTRUMENT TOR MEASURING STANDING TIMBER. 



at the same time both sides of it, without straining it,, 

 keeping the. graduated side of the index uppermost, on 

 -which the girth will be shown, after allowing for the bark, 

 by the inner edge of the brass on the right hand leg. An 

 operation so easy and simple,' that a person of the meanest 

 capacity might measure a great number of trees in a day. 

 Instrument for For taking the height of a tree, I would recommend 



h«? S ht ring thC deal rods ° f SCTen feet )on £' ™ ac,e so as to fit into ferrils at 

 the end of each other, tapering all the way in the same man- 

 ner as a fishing rod. A set of five of them, with feet marked 

 on them, would enable a man quickly to measure a tree of 

 more than forty feet high, as lie would be able to reach him- 

 self about K'ven feet. 



Improvements, The improvements it is capable of are, making a joint 



^ade™ 1 ^ ^ * n tJie arcl1 or scalt '' to cnab,c u to snut U P (when the legs 

 are closed) towards the centre, which would make it easier 

 to carry. Secondly, as it. sometimes happens, that standing 

 timber is sold without any allowance for bark, and at other 

 times with a less allowance than one inch in thirteen, two 

 other scales on the index might be added in such cases, one 

 without any allowance, and the other to allow as might be 

 agreed on. I would have added these, but thought the 

 Society would rather see it in the state in which it has been 

 tried on a large survey, as any artist can with great ease add 

 ■whatever scale he pleases. The present scale allows one 

 inch in thirteen for bark, and is calculated on the following 

 data. The diameter of a circle the quarter circumference 

 of which is 26 inches, is 33 ^% inches. The diameter of a 

 circle, the quarter girth of which is 6f inches, is 8 7 2 /o inches. 

 To graduate the scale, the instrument is opened so as to take 

 in at the small end between the touching points 8 --J^ inches, 

 and a mark is made on the arch to denote 6 inches quarter 

 girth : it is then opened so as to take in 33 i%% inches, and 

 another mark is then made on the arch, to denote two feet 

 quarter girth ; (these marks are made close to the inner edge 

 of the brass on the right hand limb) : the space between them 

 is then divided into eighteen parts, which represent inches, 

 and are again divided into halves, for half inches; if any notice 

 is to be taken of quarter inches, the eye will easily make a 

 farther decision. 



I beg 



