Εικόνες σελίδας
PDF

492. A Cord of wood is a pile 8 feet long, 4 feet wide, and 4 feet high. It contains 8 cord feet, or 128 cubic feet.

493. A Cord Foot is a part of this pile 1 foot long. It is thus 1 foot long, 4 feet wide, and 4 feet high, and contains 16 cubic feet.

Rule.- To find the number of cords in a pile of wood, find the number of cubic feet and reduce to cord feet and cords.

EXAMPLES FOR PRACTICE. 1. How many cords in a pile of wood 32 ft. long, 8 ft. high, and 6 ft. wide ?

SOLUTION.—The number of cubic feet equals 32X8X6, which equals 1536; dividing by 16, to reduce this to cord feet, we have 96 cord feet; dividing by 8 to reduce this to cords, we have 12 cords.

2. How many cords of wood in a pile 28 ft. long, 12 ft. wide, and 6 ft. high ?

Ans. 15 cd. 6 cd. ft. 3. If a pile of wood is 10 ft. high and 6 ft. wide, how long must it be to contain 12 cords?

Ans. 25 ft. 7} in. . 4. A man bought 50 cords of wood, 3 ft. long, and proposes to put it in a pile 12 ft. high ; how long will the pile be ?

Ans. 152.8 ft. 5. How much will a pile of wood weigh, 12 ft. long, 4 ft. wide, and 6 ft. high, of which is white oak, and the rest white pine, provided a cubic foot of white oak weighs 55 lb., and of white pine 30 lb. ?

Ans. 7 tons 40 lb. BOARDS AND TIMBER. 494. Boards and Timber are usually estimated in what are called board feet, instead of in cubic feet.

495. A Board Foot is 1 foot long, 1 foot wide, and 1 inch thick. A cubic foot, therefore, contains 12 board feet. Hence, board feet may be reduced to cubic feet by dividing by 12; and cubic feet to board feet by multiplying by 12.

496. A Standard Board, in commerce, is 1 inch thick; and its contents in board feet are the product of its length and breadth in feet.

[graphic]

Board feet are usually known as square feet. Boards are quoted by the hundred or the thousund, meaning a hundred square feet, or a thousand square feet. Round timber, as masts, etc., is estimated in cubic feet; hewn timber, as beams, etc., either in board or cubic feet; lumber and sawed timber, as planks, scantling, joists, etc., in board feet.

Rule 1.– To find the contents of a board, multiply the length in feet by the width in inches, and divide the product by 12.

Rule II.— To find the contents of a plank, joist, etc., multiply the length in feet by the width and thickness in inches, and divide the product by 12.

NOTES.--1. If one of the dimensions is inches and the other two are feet, the product of the three will be board feet.

2. When a board tapers regularly, the length must be multiplied by the mean width, which is half the sum of the width of the two ends.

3. Duodecimals were formerly used for computing the contents of boards, etc., but this mode of reckoning is becoming obsolete.

EXAMPLES FOR PRACTICE. 1. What are the contents of a board 16 ft. long and 10 in. wide ?

SOLUTION.-Multiplying the length in feet by the width in inches, we have 16x10=160; and dividing by 12, we have 13} board feet, or square feet.

2. What are the contents, in board feet, of a board 15 ft. long and 1 ft. 3 in. wide ?

Ans. 18% board ft. 3. How many board feet in a board 17 ft. long, 15 in. wide at one end and 10 in. at the other? Ans. 1727 board ft.

4. How many board feet in a board 21 ft. long, 18 in. wide, and 21 in. thick ?

Ans. 78% board ft. 5. How many board feet in a beam 25 ft. long, 1 ft. 3 in. wide, and 1 ft. 3 in. thick ?

Ans. 4688 board ft. 6. How many board feet in a joist 19 ft. long, 2 ft. wide, and 9 in. thick ?

Ans. 342 board ft. 7. How many board feet in a stick of timber 27 ft. long, 11 in. wide at one end and 8 in. wide at the other, and 12 in. thick?

Ans. 256) board ft. 8. What will it cost to floor a 3-story warehouse, 32 x 25 ft., with plank 2 inches thick, at $35 p M.? Ans. $168.

9. How many square feet of boards will it require to make a box 3 ft. 3 in. by 2 ft. 9 in., and 16 inches high on the outside?

Ans. 313sq. ft. 10. How many feet of boards are actually used in making a crib 40. ft. long, 61 ft. wide, and 127 ft. high, the roof being nearly flat and projecting 3 in. on each side, and what will it cost to tin the roof at $3.25 a square ?

Ans. 173635 ft. ; $9.32%. 11. Make out a bill for the following lumber, bought by John French of Varney & Jones, Augusta, Me., Oct. 15, 1875: 118 boards, 12 in. by 18 ft. @ $16 p M.; 45 planks, 3.1 X16, by 15 ft. @ $19.50 p M. ; 84 joists, 4x 12 by 20 ft. @ $131 M.; 75 scantling, 31x 44 by 15 ft. @ $11; p M.; 25,000 shingles @ $15.1 p M. What is the amount of the bill?

Ans. $590.98. MASONRY, BRICKWORK, ETC. 497. Masonry is usually estimated by the perch and the cubic foot; sometimes by the square foot or the square yard.

498. A Perch of stone or of masonry is 16.2 ft. long, 11 ft. wide, and 1 ft. high ; it contains 24; cubic feet, but when stone is built into a wall, 22 cubic feet make a perch, 2 cu. ft. being allowed for mortar and filling.

499. Excavations and Embankments are estimated by the cubic yard. A cubic yard of earth is called a load.

500. Brickwork is generally estimated by the thousand bricks, but sometimes in cubic feet.

In estimating labor, bricklayers and masons measure the length of the wall on the outside. The corners are thus measured twice, but this is considered an allowance for the greater difficulty of building them. No allowance is made for windows and doors, except by special contract, in which case it is customary to allow one-half of the space actually required.

In estimating material, allowance is made for doors, windows, and corners. It should be remembered that the length and breadth of a corner are each equal to the thickness of the wall.

The average size of bricks is 8 in. X 4X2, but Philadelphia and Baltimore bricks are 8 in. X 43 X 23; Maine bricks, 71 in. x 33 x 23; North River bricks 8 in.X31X21; and Milwaukee bricks 8.1 in. X 43 X 23.

To build one square foot of wall 1 brick or 4 inches thick requires 7 common bricks; 2 bricks, or 9 in. thick, 14 bricks; 3 bricks, or 13 in. thick, 21 bricks.

Rule I.- To find the number of perches in a piece of masonry, divide the number of cubic feet by 243.

Rule II.— To find the number of common bricks required for a wall or building, multiply the number of square feet in the wall by 7 if the wall is 1 brick thick ; by 14, if 2 bricks thick ; by 21, if 3 bricks thick.

Rule III.— To find the number of any kind of bricks required for a wall or building, add , of an inch to the length and the thickness of the brick, divide 144 by the product of these two sums to find the number of bricks in a square foot of wall 1 brick thick, and multiply by the number of bricks in the thickness, and this product by the number of square feet in the wall.

NOT E.--An old rule was--Deduct to of the solid contents for the mortar and divide the remainder by the contents of one brick. We may also find the contents of a brick with the mortar surrounding it, and divide a cubic foot by this quantity, to find the number of bricks in a cubic foot.

EXAMPLES FOR PRACTICE. 1. How many bricks will be required to build a house in Baltimore 25 ft. front, 80 ft. deep, the wall being 34 ft. high and 3 bricks thick, allowing 352 sq. ft. for doors and windows, the mortar being 1 of an inch thick ? SOLUTION. — Since

OPERATION. the house is in Balti

8.9 X 2=221. sq. in., surface of one brick. more, the outer sur

144 = 22 =654, No. bricks in sq. ft. face of the bricks,

(25+80) X 2= 210, length of outside wall. after adding of an

13x4=52 in.=41 ft., length of corners. inch, equals 81 X 25,

210—41= 2053, length of walls. which multiplied to

205 x 34569923, surface of walls. gether, give 22. sq. 69921–352=6640?. in. for the surface of

66403 X 61149X3= 128572119. 1 brick; dividing 144 by 22, we have 6,549, the number of bricks in 1 square foot of wall one brick thick. Adding 80 ft., the length of the house, to 25 ft., the breadth, and multiplying by 2, we have 210 ft., the distance around the house; now since a wall 3 bricks thick is 13 in. thick, the length of corners will be 4 times 13, or 52 inches, or 41 ft., which subtracted from 210 ft., leaves 2054 ft., length of walls; multiplying by 34, the height, we have 6992 sq. ft., surface of walls; and subtracting 352 sq. ft., we have remaining 6640 sq. ft., which multiplied by 6,54. and also by 3, the number of bricks in thickness, gives 128572 39. bricks.

2. What will be the cost of excavating a cellar 25 ft. long, 15 ft. wide, and 7 ft. deep, at 45€ a load? Ans. $43.75.

3. How much stone will be required to build a wall around a garden 15 rd. long, and 12 rd. wide, the wall being 4 ft. high and 2 ft. 6 in. thick; and what will be the cost at $3.25 a perch?

Ans. 355,95 perches ; $1156.87. 4. I have a quantity of stone quarried amounting to 11880 cubic feet, which I wish to use in building a wall; how many perches of stone have I, and how many perches of masonry can I build from it?

Ans. 480 ; 540. 5. What will it cost to build, of average bricks, a house 50 ft. long, 22 ft. wide, and 23 ft. high, the wall being 13 in, thick, there being two doors, each 7x31 ft., 1 door 6x31 ft., and 18 windows, each 6x 3 ft., the brick costing $9p M. and laying $2.50 p M.?

Ans. $706.55. 6. What will be the cost of building a house 36 ft. square, the wall being 24 ft. high and 3 bricks thick, of Milwaukee bricks, 216 sq. ft. being allowed for doors and windows, the mortar being 1 of an inch thick, the brick costing $10.50 * M. and the laying $2.75 p M. ?

Ans. $798.07. 7. Mr. Nelson has a cellar 45 ft. long, 27 ft. wide, and 8 ft. deep, which he contracts to have walled at a cost of $3.871 a perch, the wall to be 2 ft. thick, and one-half to be allowed for corners; what will be the cost? Ans. $350.71.

8. Mr. James, having contracted to build a house, agrees to pay John Newman $0.45 a load for digging the cellar, and Samuel Forman $3.65 a perch for walling it with rough stone to the surface, and with cut stone above ground at 25€ per sq. ft.; the cellar is to be 54 ft. 9 in. long, 35 ft. wide, and 51 ft. deep, and the wall 1 ft. thick and 3 ft. high above ground; what will the work cost? Ans. $565.07.

MEASURES OF CAPACITY. 501. Measures of Capacity are volumes used to determine the quantity of fluids and many dry substances.

502. The Principal Measures of capacity are the gallon for liquid subs: ances, and the bushel for dry substances.

« ΠροηγούμενηΣυνέχεια »