On Measuring growing Timber. 259 



of the tree coincided with the j)aper at 95 ft. distance; which, 

 with the 5 ft. below the paper, made the total height of the tree 

 100 ft., being 10 ft. more than it had always been previously 

 considered to be. The measurable timber height was evi- 

 dently seen to be beyond a broken stump ; but as, above that 

 point, it was of a very coarse description, from the numerous 

 large side branches striking off', that point was assumed, and 

 found, by stepping forward with the sextant set at 45°, to be 

 61ft. above the mark, and thus 66 ft. above the root. An 

 observation was then made for the diameter at middle height, 

 and found to range between 2° 45' and 2° 58', there being some 

 inequalities at the place where it required to be taken ; but most 

 of the observations gave it above 2*^ 50'. The vertical angle was 

 25°; and, the secant of 25 being riO, which, multiplied by 61, 

 gives the distance from the eye to the point whence the diameter 

 was taken to be 67 ft., taking the medium angle for the 

 diameter (2° 52'), its tangent is -05007; which, multiplied by the 

 distance (67), gives 3-354-69 for the diameter; and 3*555 x 3*142 

 makes the circumference 10'5414, or say 10 ft. 6^ in.; and, 

 making an allowance of 10:jin. for the bark, leaves 9ft. Sin. 

 for the rectified girt; the quarter of which is 2ft. 5 in., which, 

 being squared and multiplied by the length or height of 66 ft., 

 makes the cubical measurement to be 386 ft. 



Some other observations were taken thus: — The diameter at 

 the top of what was taken for the measurable timber was found 

 to subtend an angle of 1° 20'; and, the vertical angle being 45°, 

 the secant of which is 1*41, which, multiplied by 61, makes the 

 distance 86 ft. ; and this, multiplied by the tangent of 1° 20', 

 being — *0233, makes the diameter at that point 2 ft; and which, 

 multiplied by 3*142, makes the circumference 6 284, or 6ft. 

 3 in., leaving 5 ft. 9 in. for the rectified girt, after allowance for 

 bark, and the quarter to be 1 ft. 5 in. In like manner, the 

 diameter near to the ground subtended 4° 30'. The tangent is 

 0*787 X 62 ; the distance gives 4 8794 for the diameter; and, being 

 multiplied by 3*142, makes the circumference to be 15*331, 

 equal to 15 ft. 4 in. ; allowance for bark, 1 ft. 4 in., leaves 14 ft. 

 for the rectified girt; the quarter of which being 3 ft. 6 in., and 

 the quarter at the top being I ft. 5 in., the medium is 2 ft. 5^in. ; 

 which, being squared and multiplied by the height, makes the 

 cubical contents of the tree to be 396 ft. 



An observation was taken for the diameter at the mark level 

 with the eye (being 5 ft. above the ground), for the satisfaction 

 of the party who was present; which was found to be 3° 40', 

 which makes the circumference 12 ft. 3 in. It was tried by the 

 tape-line, and found to be 12 J ft. At 18 in. above the ground, 

 the tree measures 16 ft. round; but this is occasioned by some 

 inequalities ; and the angle of 4° 30', for the measurement at the 



