2. Find the mean area of a round tree, and multiply it by the length for the content.
To find the weight of a tree.
Find its content in feet, and multiply that by the specific gravity of the wood.
(Vide [Gravity], and Table of Specific Gravities. [Page 318.])
Example.—Required the weight of an elm-tree; whose mean girt is 5 feet, and length 60 feet.
5 4 = 1·25 1·25 × 1·25 = 1·5625.
1·5625 × 60 = 93·75. Content in feet.
TONNAGE.
Table of Tonnage, and Weight of one of the following Carriages, Carts, Waggons, Gyns, &c., used in land service.