edgeways. Give the inside dimensions of a box which will serve for packing.

72 RODS

108 RODS

5. The five circular ridges of a ceiling, as shown in the diagram, are to be gilded at an expense of 20¢ a foot. If AB is 42 ft., find the entire cost.

Lesson No. 20.

General Review (Continued)

EXERCISES

1. Find the number of perches of stone masonry in a rectangular foundation 36 ft. by 18 ft., outside measurement; the wall to be 12 ft. high and 14 ft. thick.

2. Twenty-four circular tanks, each 7 ft. in diameter and 8 ft. deep, but without covers, are to be painted inside and outside. Find the cost at 51 a square yard.

3. A circular lake, the radius of which is 63 rd., is frozen over to a depth of 1 ft. How many tons of ice can be taken from it if a cubic foot of ice weighs 57 lb.? (Take 2000 lb. to the ton. Multiply the area in feet by 1 to get the number of cubic feet.)

4. Find the cost of a single coat of plaster on the walls and ceiling of a room 24 ft. by 18 ft., and 10 ft. high, allowing 100 ft. for doors, windows, etc., at 15 a square yard.

5. How many feet of lumber in a circular platform 2 in. thick and 28 ft. in diameter?

6. The pickets of a fence are 3 in. wide and 2 in. apart. How many pickets in a fence one-fourth of a mile long?

7. A surveyor reports the length of a projected railway as 19,680 ch. What will it cost to build the road at an estimate of $18,000 per mile?

8. Find the cost of 24 blocks of marble, each 11 ft. by 1 ft. by 10 in., at $1.50 a cubic foot.

9. How many loads of gravel will be required for a road 10 mi. long, if spread 9 ft. wide and 3 in. deep?

10. A hundred telegraph posts, each 14 in. in diameter, are to be painted to a height of 71⁄2 ft. Find the cost of the painting at 9 a square yard.

Lesson No. 21. Volumes and Weights of Liquids

There are about 231 cu. in. in a gallon. It is often necessary to estimate the number of gallons of water or other liquid in a tank, or to get the dimensions of a tank required to contain a stipulated number of gallons. The weight of water in a tank can readily be found when we know that a cubic foot of water weighs 62 lb.

EXERCISES

1. A rectangular reservoir is 22 ft. long, 21 ft. wide, and 6 ft. deep. How many gallons of water will it contain?

2. A water tank contains 17,280 gal. of water. weight in pounds does it contain?

What

3. A circular water tank is of the dimensions shown in the diagram. (a) What weight of water does it contain when full? (b) How many gallons of water does it contain when full?

NOTE. To find the volume of a circular solid similar to the above, find the area of one end and multiply by the depth.

4. A rectangular trough is to be built to hold 216 gal. It is to be 11 ft. long and 18 in. wide, inside measurement. How deep should it be?

14 ft

5. There are three vats in a manufacturing establishment, each of the shape and dimensions shown in the diagram. They are each half full of a liquid dye. How many gallons of the dye in the three vats? (See "Note" in the "Answer.")

Lesson No. 22. Lumber and Timber Estimates (Continued)

In measuring common lumber it is customary to consider lumber less than an inch in thickness as inch lumber. The more expensive lumber used in furniture and for finishing are charged for by the foot, or by the hundred feet, rather than by the thousand feet.

EXERCISES

1. How many inches in width must a lumber dealer measure off in measuring 14-ft. lumber 14 in. thick, to make 2170 ft. ?

2. Find the value of the inch lumber in a sidewalk 6 ft. wide around a square 60 yd. by 40 yd.; and two walks, each 4 ft. wide, through the middle, at right angles to each other and parallel to the sides, at $24 a thousand.

3. A stick of timber 2 ft. square and 16 ft. long is sawed into inch lumber. How many feet will it make, one-sixth being lost in sawing?

4. A board fence with posts 7 ft. apart is built with one 10-in., one 8-in., and three 6-in. boards. Find the value of sufficient 14-ft. lumber to build 40 rd. of the fence at $22 per thousand.

5. Find the value of the 11⁄2 in. plank, at $24 per thousand, that will be needed to make a land roller whose diameter is 3 ft. and length 9 ft.

6. How many feet of inch lumber in the two ends of a barn the elevation of which is shown in the accompanying diagram? AE or BF is 36 ft.

7. How high should the ceiling of a schoolroom 20 ft. by 25 ft. be, to allow 150 cu. ft. of air to each of 50 pupils? 8. If a bushel of grain occupies 1 cu. ft., how deep must the grain be in an 18-ft. by 5-ft. bin, to contain 800 bu.?