Note 1.—If the tree taper regularly from the one end to the other, either take the mean breadth, and thickness in the middle, or take the dimensions at the two ends, and half their sum will be the mean dimensions; which, multiplied as by the above rule, will give the content, nearly.
Note 2.—If the piece do not taper regularly, take several different dimensions, add them all together, and divide their sum by the number of them, for the mean dimensions.
Example.—Required the content of a piece of timber 16 feet long, and side of square 14 inches.
| ft. in. ft. in. ft. | ft. in. | ||
| 1 2 × 1 2 × 16 | = | 21 9. | Content required. |
To find the solidity of round, or unsquared timber.
1. Multiply the square of the quarter girt (or the square of ¼ of the mean circumference), by the length, for the content.
Note.—When the tree is tapering, take the mean dimensions, either by girting it in the middle for the mean girt, or at the two ends, taking half the sum of the two; or by girting it in several places, then adding all the girts together, and dividing the sum by the number of them for the mean girt. But when the tree is very irregular, divide it into several lengths, and find the content of each part separately.
Example.—Required the content of a tree, whose mean girt is 3·15 feet, and length 14½ feet.
3.15 4 = ·7875 ·7875 × ·7875 = ·62015625.
·62015 × 14·5 = 8·9922 feet of solid timber. The content required.