WOOD, LUMBER AND BOARD MEASURE Measurement of Wood and Lum ber.—Among the most frequent ap plications of cubic or capacity meas ure is the measurement of cord wood for fuel and of round timber or sawed lumber for building and other 'pur poses.
Wood is usually cut for fuel into 4 feet sticks. A cord of wood is a pile 8 feet long, 4 feet wide, and 4 feet high. It contains 128 cubic feet. A cord-foot is of this pile or a pile of wood 4 feet long, 4 feet high, and 1 foot wide.
To obtain the number of cords in a pile of wood, multiply the length of the wood by the height of the pile ex pressed in feet and that result by the length of the pile in feet. Divide the product by 128 and the quotient will be the number of cords.
Board Measure.—Lumber is sold at so much " per M," naeaning per thou sand feet B. M. or board measure. Board measure is used in measuring lumber sawed into boards, planks, joists, scantling, etc. The unit of board measure is the board foot, which is 1 foot long, 1 foot wide, and -1 inch thick, and hence is equal to of a cubic foot. Hence to fnad the number of board feet in a board or other piece of lumber having square edges and parallel sides, first find the surface of the board in square feet and multiply the product by the thickness in inches. Boards 1 inch in thickness or less are sold by the square foot, surface measure.
Thus a board 1 foot wide and 16 feet long, if 1 inch or less in thick ness, would contain 16 square feet or 16 feet board measure. A board 18 feet long, 6 inches wide, and 1 inch or less thick would contain 18 X 1 foot B. M. or 9 feet B. M. A joist 12 feet X 6 inches X 2 inches contains 19 X g X feet B. M. or 12 feet B. M.
The width of a board that tapers uniformly is averaged by taking one half the sum of the two ends, or, in practice, by measuring across the middle. In practice the width of a board is reckoned to the next smaller half inch. Thus, a width of 61 inches is taken as 6 inches, and the width of 61 inches is taken as 61 inches.
To Measure Inch Boards.—Multi ply the length in feet by the width in inches, and divide the product by 12. The quotient will be the contents in feet. For lumber 12, inches thick, add / to the quotient. If inches thick, add 1. If 1/ inches thick, add /. If inches thick, divide by 6 in stead of by 12. If 2/ inches thick, add 1 to the quotient and so on. If
3 inches thick, divide by 4. If 4 inches thick, divide by 3. Or to as certain the contents (board measure) of timber, including scantling, joist, planks, sills, rafters, etc., multiply the width in inches by the thickness in inches, and that by the -length in feet and divide the product by 12. The result vvill be the number of feet.
The measurement of round logs is intended to give the amount of lum ber in board measure that can be sawed from them. Logs not over 15 feet in length are measured by means of a table stamped on calipers, the length and diameter of the small end being given. In the case of logs over 16 feet in length, the average di ameter is taken.
Or to measure round timber take the girth in inches at both thc large and the small ends, add them, and di vide by R, which gives the mcan girth. The square of 1 of the mean girth multiplied by the length of the tim ber in feet will give the contents in cubic feet. This is the common prac tice based on the estimate that round timber when squared loses 1. The result gives of the actual contents, the remaining 1 being allowed for waste in sawing.
Or, by another rule, subtract 4 from the diameter of the log in inches, multiply the square of 1 the remain der by the length of the log in feet. These two rules should give apprmd mately the same result.
Or to find how many solid feet a round stick of timber, if of the same thickness throughout, will contain when squared, square half the diame ter in inches, multiply by and mul tiply this product by the length in feet. Finally, divide by 144; the re sult will be the contents of the squared timber in solid feet.
Or to find the number of feet in timber having the bark on, square of the circumference in inches and multiply the product by twice the length in feet. Then divide by 144. Subtract /la to 11,, of the total, accord ing to the thickness of the bark. As a general rule, to find the solid con tents of sawn lumber multiply the depth in inches by the breadth in inches and multiply the product by the length in feet and divide by 141.
To determine how large a tree must be cut to get out a stick of timber a given number of inches square, divide the side of the required square by .225. The quotient will be the circum ference of the timber required.