The easiest way of measuring round timber, to get the solid contents, is to take one-fourth of the middle girth of the timber in inches, square this dimension, multiply by the length in feet, and divide by 114; the result is the reputed cubic contents. If the bark is on, make an allowance for it by deducting lin. per foot from the actual girth before dividing by 4. Example: Round log of oak 20 ft. long, 18 in. diameter one end and 12in.the other, girth 48in. Then 48 in. = 4ft., lin.per foot = 4in., and 48 - 4 = 44 in.; quarter girth = 11 in., 11 squared = 11 x 11 = 121, and 121 x 20 = 2,420. Then 2420 = 16.8. say 17 cub. ft.