By committing to memory the following short table of quarter-girths much time in calculating and consulting authorities will be saved. 6-inch quarter-girth will give contents equal to ¼ the entire length in feet. 7 ” ” ” ⅓ 8½ ” ” ” ½ 10 ” ” ” ⅔ 12 ” ” ” 1 13 ” ” ” 1¼ 14¾ ” ” ” 1½ 16 ” ” ” 1¾ 17 ” ” ” 2 19 ” ” ” 2½ 21 ” ” ” 3 22½ ” ” ” 3½ 24 ” ” ” 4 27 ” ” ” 5 29½ ” ” ” 6 31¾ ” ” ” 7 34 ” ” ” 8 36 ” ” ” 9 The sliding rule is also useful for determining contents. The proper allowance to be made for bark is half an inch for every foot of quarter-girth for oak and elm under 12 in. quarter-girth, and an inch for all beyond, but it is quite impossible to fix upon any one uniform scale that will meet even the majority of circumstances. Trees growing in exposed situations will frequently have bark almost double the thickness of those of a similar size in the woodland. My plan has been always to allow for the bark of each tree at the time of measurement. =Measuring Standing Timber.=—For this a pliable pole 18 ft. long, marked in feet, and the girt-strap already referred to are the necessary equipment. In estimating the number of feet of timber upon a large area, it is not always necessary to measure each tree separately, particularly when the whole situation is composed of one species, and the individual trees are about the same age and size, as by multiplying the total number of trees by the average content of those selected and measured a very just calculation will be arrived at. Great care in their selection, and considerable judgment in taking the average will, however, be required. [Illustration: MEASURING HEIGHT OF TREES] When each tree is to be measured separately two assistants will be required, one to carry the 18-ft. pole, and the other the girting-strap. Sometimes, when the timber is of great height, jointed bamboos are used, and a light ladder brought into requisition. In carrying out the work in this way, the man with the pole declares the height of the tree, and the one with the tape the quarter-girth.