BINS, TANKS, AND CISTERNS. 146. The capacity of bins is estimated by the bushel, and the capacity of tanks and cisterns by the gallon, barrel, or hogshead. The Standard Bushel of the United States is a cylindrical measure 18 inches in diameter and 8 inches deep. RULE. To find the number of bushels in a bin, divide the contents in cubic inches by 2150.42. Since 1728 is to 2150.42 as 4 is to 5, nearly, for practical purposes of the number of cubic feet will equal the number of Estimate, by taking of the number of cubic feet as bushels, the capacity of a bin 1. 8 ft. by 4 ft. by 5 ft. 2. 6 ft. by 3 ft. by 10 ft. 3. 12 ft. by 40 ft. by 8 ft. 4. 20 ft. by 16 ft. by 12 ft. Calculate exactly the capacity of a bin 5. 4 ft. by 5 ft. by 6 ft. 6. 8 ft. by 4 ft. by 3 ft. 7. 10 ft. by 12 ft. by 15 ft. 8. 6 ft. by 8 ft. by 10 ft. 9. What is the difference between the exact number of bushels in a bin 3 ft. by 4 ft. by 5 ft. and the number found by estimating of the number of cubic feet as bushels? 10. A bin 8 ft. by 10 ft. by 12 ft. is full of wheat; what is the difference between the exact number of bushels in the bin and the number obtained by estimating as above? 11. A bin 16 ft. long, 10 ft. wide, and 8 ft. high is full of wheat; at 60 cents a bushel how much more is it worth, calculated exactly, than by estimating of the number of cubic feet as bushels? 12. How many barrels of flour can be made from the contents of a bin 16 ft. long, 10 ft. wide, and 8 ft. deep, if it is full of wheat, and if a bushel of wheat makes 50 lb. of flour? 13. How many gallons of water will a cistern 8 ft. deep and 6 ft. in diameter hold? 14. How many barrels of water in a well 4 ft. in diameter, if the water is 15 ft. deep? 15. How many hogsheads of water will a stand-pipe hold whose diameter is 10 ft. and altitude 75 ft.? 16. If a cubic foot of water weighs 1000 oz., how many tons will the water in a stand-pipe whose diameter is 10 ft. and altitude 75 ft. weigh if the stand-pipe be full? 17. If a well holds 20 hhd. of water and is 4 ft. in diameter, how deep is it? 18. What is the depth of a cylindrical measure 4 in. in diameter which will hold a dry gallon of 268.8 cu. in.? BOARDS AND TIMBER. 147. Boards one inch or less in thickness are estimated by the square foot. Thus, a board 16 ft. long, 15 in. wide, and 1 in. or less in thickness contains 16 X 20 sq. ft. When lumber is more than one inch thick the thickness is taken into account, and the lumber is estimated by what is called a Board-foot, which is 1 foot square and 1 inch thick. Thus, a board 16 ft. long, 15 in. wide, and 11⁄2 in. thick contains 16 × 1 × 11⁄2 = 30 ft. It is readily seen that 1 Cubic foot = 12 Board-feet. RULE. I. To find the contents of a board, multiply the length in feet by the width in inches, and divide by 12. II. To find the contents of timber more than an inch thick, multiply the length in feet by the width and thickness in inches, and divide by 12. WRITTEN EXERCISES. How many board-feet in a board 1. 16 ft. long, 9 in. wide, and 1 in. thick? 2. 18 ft. long, 12 in. wide, and 14 in. thick? 3. 15 ft. long, 8 in. wide, and 2 in. thick? 4. 20 ft. long, 15 in. wide, and 11⁄2 in. thick? 5. 12 ft. long, 16 in. wide, and 3 in. thick? How many board-feet in a scantling, etc. 6. 12 ft. long, 3 in. wide, and 4 in. thick? 7. 24 ft. long, 3 in. wide, and 7 in. thick? 8. 30 ft. long, 5 in. wide, and 6 in. thick? 9. 20 ft. long, 3 in. wide, and 6 in. thick? 10. 15 ft. long and 12 in. square? 11. 18 ft. long and 6 in. square? 12. What will 20 scantling 16 ft. long, 3 in. wide, and 4 in. thick cost, at $25 per thousand? 13. What cost 40 boards 16 ft. long, 15 in. wide, and in. thick, at $30 a thousand? 14. What is the cost of 5 girders, each 50 ft. long, 14 in. wide, and 12 in. thick, at $30 per M.? 15. What will it cost to enclose a rectangular lot 120 ft. long and 90 ft. wide with a tight board fence 6 ft. high, if the boards are worth $24 per M.? 16. What will it cost to lay a floor 80 ft. long and 60 ft. wide at $35 a thousand, adding for grooving? MASONRY AND BRICKWORK. 148. Masonry is commonly estimated by the perch, which contains 24 cubic feet; in many cases, however, it is estimated by the cubic foot and cubic yard. 149. Brickwork is estimated by the thousand bricks. Bricks vary considerably in their dimensions, an ordinary size being 8 inches long, 4 inches wide, and 2 inches thick. In estimating the number of ordinary bricks required to build a wall, of an inch for mortar is added to the length and thickness of each brick, making the above dimensions of the face, or surface exposed to view, 8 by 24 inches, or 27 square inches; hence in a wall one brick in thickness each square foot, or 144 square inches, of wall surface would require as many bricks as 297 is contained times in 144, or a little more than 7 bricks, seven, however, being the number usually taken. If the wall is two bricks in thickness, 14 bricks will be required; and so on. Hence the common RULE. To estimate the number of bricks required to build a wall, multiply the number of square feet in the surface by 7 when the wall is 1 brick thick; by 14 when the wall is 2 bricks thick; and by 21 when the wall is 3 bricks thick. NOTE. In cases where bricks vary considerably from the ordinary dimensions a more accurate method is to add of an inch to the length and thickness of a brick, and divide 144 by the product of these increased dimensions for the number of bricks to a square foot of wall surface. 150. In estimating material for the walls of a building, whether brick or stone, allowance is made for the doors, windows, and corners. In estimating the cost of labor the length of the wall is measured on the outside; the corners are thereby measured twice, but this is considered an offset for the greater labor required in their construction. For the same reason no allowance is made for doors and windows, except in case of special contract, when one-half of the actual space is usually deducted. NOTE. In sworn measurements of material in brick walls already built it is customary to count the bricks in a layer and multiply by the number of layers, making proper allowance for doors and windows. Generally, a wall two bricks thick is regarded as a 9-inch wall; one three bricks thick, a 13-inch wall; 4 bricks thick, a 17-inch wall, etc. RULE. To find the number of perches of stone in a wall, divide the number of cubic feet in the wall by 243. WRITTEN EXERCISES. 1. How many perches of stone in a wall 80 ft. long, 6 ft. high, and 2 ft. thick? 2. How many bricks will be required to construct a wall 40 ft. long, 12 ft. high, and 13 in. thick? 3. How many bricks will it take to build a wall around a square yard 40 ft. on a side, if the wall is 7 ft. high and 3 bricks thick? 4. How many bricks are required to build the walls of a house 36 ft. long, 28 ft. wide, and 22 ft. high, the walls to be 13 in. thick, allowing 500 sq. ft. for doors and windows? 5. What will it cost to lay the bricks in a hall 120 ft. long, 75 ft. wide, 30 ft. high, and 21 in. thick, allowing one-half for doors and windows, there being 12 windows 3 ft. by 12 ft. and 4 doors 5 ft. by 10 ft., at $3 per thousand? |