BOARD MEASURE.

228. A Board Foot is a square foot of board one inch thick; and

12 board feet make 1 cubic foot.

229. Lumber, or sawed timber, as boards, plank, joists, and the like, is estimated in board feet.

Hewn Timber is estimated either in board feet or cubic feet.

In the measurement of lumber, or hewn timber which tapers, half the width or half the thickness of the two ends is taken.

230. To find the contents of a piece of lumber in board feet,

Multiply the product of the length and width taken in feet by the thickness in inches.

NOTE. Lumber less than an inch thick is measured as if it were an inch thick. In computations, therefore, thickness may be disregarded if an inch or less.

In the measurement of box boards, however, the standard of thickness is § of an inch.

WRITTEN EXERCISES.

39. How many board feet in a joist 21 feet 6 inches long, 4 inches wide, and 3 inches thick?

40. How many board feet in a board 16 feet long, 1 foot

6 inches wide, and 2 inch thick?

41. Required the contents in board feet of a plank 20 feet long, 16 inches wide, and 2 inches thick?

42. How many board feet in a piece of hewn timber 20 feet long, 10 inches thick, and whose width tapers from 18 to 16 inches ?

43. What will be the cost of 44 spruce joists, each 18 feet long, 9 inches wide, and 3 inches thick, at $23 a thousand feet?

44. What is the value of 18 planks 2 inches thick, 24 feet long, 21 inches wide, at $ 35 a thousand feet?

MISCELLANEOUS EXERCISES.

45. A rectangular lot containing 9432 square feet has a frontage of 131 feet. What is its other dimension?

46. A wagon 8 feet long and 3 feet wide has wood piled on it 5 feet high. How much is the wood worth at $5.50 a cord?

47. How many board feet of plank 2 inches thick will be required to cover a platform 30 ft. 6 in. long and 20 ft. wide?

48. What must be paid, at the rate of $ 40 a thousand feet, for 6 boards 16 feet long, and in width tapering from 28 to 20 inches?

49. A cistern 2.50 meters long, 90 centimeters wide, and 110 centimeters deep, will hold how many hektoliters of water?

50. How many rolls of paper 12 yards long and 1 foot 8 inches wide will be required to paper a room 18 feet long, 12 feet wide, and 9 feet high, no allowance being made for windows and doors?

51. Allowing .8 of a bushel to a cubic foot, how many bushels of corn can be put in a bin whose inside measure is 4 feet long, 3 feet wide, and 4 feet deep?

52. Allowing 7 gallons to a cubic foot, how much will a tank hold whose inside measure is 2 ft. 6 in. long, 2 ft. wide, and 1 ft. 9 in. deep?

53. Allowing for each square foot of surface of a brick wall twice as many bricks in number as the wall is inches thick, how many bricks are there in a wall 40 feet long, 12 feet 6 inches high, and 8 inches thick?

54. If a ton of 2000 pounds of Lehigh coal fills 40 cubic feet, and of Lackawanna coal 45 cubic feet, how much of each kind will fill a bin 8 feet long, 5 feet wide, and 4 feet deep?

55. Water is flowing into a cistern whose rectangular base is 4840 square inches. How many cubic feet will have been supplied when the depth of water is 3 feet, and what will be its weight at the rate of 1000 ounces a cubic foot?

56. How many cubic feet in the walls of a cellar, whose length is 33 feet, width 30 feet, and depth 9 feet, allowing the thickness of the walls to be 18 inches, and the lap of the one wall by the other at each corner of the cellar to be 18 inches?

QUESTIONS.

215. What is a plane figure?

216. What is the perimeter of a plane figure? 217. The area of a plane figure? 218. To what is the area of a rectangle equal ?

219. What is a triangle? The base of a triangle? The altitude? 220. How is the area of a triangle found?

221. How may the circle be regarded? To what is the area of a circle equal? 222. To what is the circumference equal? To what is the diameter equal?

223. What is a rectangular volume? What are the dimensions of a rectangular volume ? 224. The contents? 225. What is a cylinder? The altitude of a cylinder? 226. What are the contents of a cylinder? To what is the curved surface of a cylinder equal?

227. What range of wood makes a cord? How much of such a range is a cord foot?

228. What is a board foot? 229. How is lumber estimated? How is hewn timber estimated? 230. How are the contents of a piece of lumber found?

224. The contents of a room divided by the area of the floor will give what?

REVIEW.

ORAL EXERCISES.

231. 1. The top of your desk is 2 ft. long and 18 in. wide. How many yards around it ?

2. It is 1 miles to the post-office.

How many miles do I travel in making three round trips to it?

3. How many score in a gross ?

4. My hens lay an egg apiece daily. How many dozen do 3 of them lay in 3 weeks 3 days?

5. If a ton of coal measures 40 cu. ft., how many tons will two 5-foot cubical bins hold?

6. How many degrees does the minute-hand of a clock move over in 45 minutes?

7. What is the perimeter of the largest surface measure? 8. What is the area of the entire surface of a 4-foot cube? 9. How wide must a yard of ribbon be to contain 144 sq. in.? 10. What will it cost to carpet a room 18 ft. square at $1 per square yard?

11. What costs a mile of wire at a cent a foot?

12. At 30 cents a gallon, what is my milk-bill for April? I take 2 quarts daily.

13. What will a 12-inch cube of marble cost at one cent per cubic inch?

14. 3 of 48 is of what number?

15. If ounce of tea costs 5 cents, what will 2 pounds cost?

16. How many acres in my grandfather's farm, which is of a mile square?

17. If 3 dozen cost $3.50, what will dozen cost? 18. Bought an acre of land at $0.50 per square rod, and sold it so as to double my money. Required my gain? 19. Bought pencils for $1.25 a gross, and sold them for a cent each. How much did I gain on 10 gross ?

20. How long must a field be that is 20 rods wide to contain 3 acres?

21. What will 7 lb. 15 oz. of sugar cost at 8 per pound? 22. A school contains 96 boys, and of the pupils are girls. How many pupils in the school?

23. The entire surface of a cube is 96 square inches. What is its edge?

24. An arc of 80 degrees is what fraction of a semi-circumference?

25. How many paper boxes 3 in. long, 2 in. wide, and 2 in. deep can be packed to a cubic foot?

26. How many writing-books of 24 pages each can be made from a ream of paper, the sheets being of the proper size?

27. What cost 18 dozen blank-books at 333 cents each? 28. I sailed for Europe May 17, and reached home again August 5. How long was I away?

29. School closes July 10 for a 6-weeks' vacation. When will it begin again?

30. What effect has moving the decimal point two places to the left, and why?

31. What is the circumference of a circle 10 inches in diameter ?

32. How many 4-inch squares in a square foot ?

33. How many days in the five shortest months of a leap year?

34. What costs a stere of wood at $ 0.75 per decistere?

35. What decimal of an acre is a plat of ground 15 rd. long and 4 rd. wide ?

36. What fraction of March has passed at noon, March 25? 37. At $7 a week, what is my board-bill from December 15 to January 22?

38. How many strips of carpeting 3 yd. wide will be required for a room 18 ft. square? How many yards?

39. Divide 0.48 by 0.2. Find their product.