518 Simple and expeditious Modes 



Art. IV. Simple and expeditious Modes of ascertaining the Heights 

 of Trees. By the Conductor and by Richard Varden, Esq. 



We intend, at present, to speak only of measuring trees for the 

 purpose of ascertaining their heights, and the diameters of their 

 trunks at a foot from the ground, to enable our friends as easily 

 as possible to send us these dimensions, as requested in our Re- 

 turn Papers. 



Trees are either crowded together, or standing singly, or so 

 as to be clear from other trees on at least one side. In the 

 former case, they are best measured by sending up jointed rods, 

 formed of deal, or any other light wood. First one rod (say 

 5 ft. or 10 ft. in length, and half an inch in diameter) is pushed 

 up the side of the trunk, and held there by the left hand ; and 

 a piece of tin tube, about 4 in. in length, and of the same dia- 

 meter in the clear, as the rod is put on the lower end of it about 

 2 in. One end of this tube beinff firm on the rod which is held 

 up alongside the trunk, with the left hand insert another rod 

 in the other end of the tube with the right hand, and so on, 

 till you have pushed the jointed rod so formed to the top of the 

 tree. Then take it down, and count the number of rods, &c., 

 putting each piece of tin tube, as it is taken off, in your pocket. 

 This may seem a tedious operation ; but a man and a boy, with 

 15 rods, and 14 pieces of tin tubing, will measure more than 

 100 trees in a day. 



When trees either stand singly, or are open on one or more 

 sides, their heights are taken with the greatest accuracy and ex- 

 pedition by looking up to them at an angle of 45°; or, in other 

 words, placing the tree in the side of an imaginary square, and 

 looking at it along the diagonal line of that square. A square 

 for this purpose any gardener may form for himself out of a 

 piece of pasteboard, or a thin deal board : he may either form 

 the square, and cut it off from a board ; or he may form it on 

 the end of a board having a straight edge, as in^g. 90. In either 

 case, a line and plummet must be suspended from one angle of the 

 square ; and the operator has only to place himself at such a 

 distance from the tree, that, when he sees the top of it, the line 

 may be exactly in the direction of the diagonal of the square, 

 as in the figure. It would be a waste of words to explain what 

 must be perfectly obvious by mere inspection of the figure, even 

 to those who have not (like most gardeners) acquired a smatter- 

 ing of geometry ; viz. that the line a b is equal in length to the 

 line be; and that the correct height of the tree will be obtained 

 by adding to it the height of the operator's eye from the ground, 

 and half the diameter of the trunk of the tree at the ground's 

 surface ; in other words, by adding to the line a b, the line a d 

 or d e (which are both of the same length as bj"), as also half 



