It will be seen that in cubic measure, the decimal point is to be moved three times as far, when changing the unit, as in linear measure.

1. How many cubic centimeters in 2.25cbm?
2. How many cubic meters in 2,162,875ccm?

195. In measuring wood the cubic meter is called a ster (st).

196. In measuring liquids, grain, etc., the cubic decimeter is always called a liter.

If the water in the liter represented in the margin stands 6cm high, how many cubic centi

meters of water are there in the measure? How many will be required to fill it? If the faucet be turned and the water allowed to run out until the measure is only half full, how many cubic centimeters will run out? How many will still remain ?

Liter Cubic Decimeter.

When the liter is the unit, the numeral prefixes have the same value as in linear measure. Thus,

1. How many liters in 1.7cbm? in 157,854ccm?

2. How many cubic centimeters in 9.51? in .0151?

3. Change 1.25hl to cubic centimeters; to the fraction of a cubic meter.

4. Convert 431.881 into hektoliters; into the fraction of a cubic meter.

5. Write .375 cbm as liters; as cubic centimeters.

6. Write 734,159.651ccm as liters; as hektoliters; as cubic meters. 7. How many cubic meters in 8,573,412.867ccm ?

8. Change the expression .734578912cbm into cubic centimeters; into liters.

9. Change 1731.5 liters into cubic meters; into cubic centimeters.

WEIGHTS.

198. The units of weight are the weights of units of pure

Cubic Centimeter. Gram Weight.

water taken at its greatest density, that is, a little above the freezing point.

The principal unit is the gram, which is the weight of a cubic centimeter of water.

The numeral prefixes have the
Thus,

same value as in linear measure.

A metric ton () = 1000 kilograms.

200. A cubic centimeter of water weighs a gram. A liter of water weighs a kilogram.

A cubic meter of water weighs a ton.

1. How many kilos* in 1.73? in 0.341 of a ton ? 2. How many kilos will a hektoliter of water weigh? 3. Convert 13,756mg into grams; into the fraction of a

kilo.

4. What is the weight in grams of 346.1ccm of water? 5. Give the weight in kilograms of 0.37615cbm of water. 6. Change .6778kg into milligrams.

7. How many milligrams in the third part of 17.4 grams?

*Kilogram is generally called kilo.

EXERCISE IV.

1. Add 17.3m, 87.41m, 271cm, 380mm, and 1.79m.

2. What is the sum of $15.87, $39.46, $47.52, $75.38, $75.89 ?

3. Add 187cm, 49.3m, 317mm, and 6.138m.

4. The door-sill being 3cm high; the door, 2.34m; the finish over it, 13.7cm; and the distance from finish to ceiling, 93cm; how far from floor to ceiling?

5. The distance to the post-office is 3.31km; thence to the mill, 1.711km; thence to the store, 3.718km; thence home, 2.543km. How long is the circuit?

6. From Portland, Me., to Boston is about 132km; Boston to Albany, 320km; Albany to Buffalo, 480km; Buffalo to Chicago, 800km; Chicago to Omaha, 800km; Omaha to Cheyenne, 780km; how far from Cheyenne to Portland? to Albany? from Boston to Chicago? from Boston to Cheyenne?

7. If I travel 789.7km a day, how far shall I go in 7 days? in 8.5? in 19.6? in 27.8? in 365 days?

8. How much will 3m of cloth cost, at $1.37 a meter? How much 5.38m, at $2.63 a meter?

9. How much will 13.4kg of opium be worth, at $8.48 a kilo? 28.79kg, at $7.96 a kilo?

10. A man bought 153 barrels of flour, at $4.875 a bbl. What did the whole cost him?

11. He gave for it 6 shares of stock, at $113.50 a share,

and the rest in cash. How much money did he pay ? 12. He paid $13.75 for storage; also, 75 cents a barrel for

freight. How much do these expenses amount to? 13. It was sold, 49 bbls. at $6.50 a bbl.; the rest at $6.25. What were the gross receipts?

14. He paid for commissions, etc., $17.50; and counts his loss

of interest at $29.30. What then is his net profit?

201. If the diameter of a circle be multiplied by 3.1416, the product is the length of the circumference. (For great accuracy the diameter is multiplied by 3.1415927.)

15. Find the circumference of a circle having a diameter of 1m.

16. Find the circumferences of circles of which the diameters are respectively 83m; 3.71m; 32.8m; 10.4cm; 11.8cm; 167.1mm; 39.3mm. Give each to the nearest tenth of a millimeter.

17. What is the length of the earth's orbit, to the nearest meter, if the diameter of the orbit is 294,481,217km? 18. How far round this world, if its diameter is 12,734km ? 19. If a carriage-wheel is 1.31m in diameter, what is its circumference? How far will it go, if it roll without slipping, in turning once? 17 times?

20. How often must that wheel turn in going 69.429m? 73.513? 17.27km ?

21. Find the reciprocal of 3.14159 to the 5th place.

202. If, therefore, a circumference be multiplied by .31831, the product is the diameter.

22. What is the diameter of the circle whose circumference is 314.159cm?

23. What is the diameter of the wheel which revolves 19.5 times in going 107.25m?

24. How thick through is a tree which has a girth of 2.97m? 25. What is the diameter of a circular field two kilometers in circumference?

26. What is the diameter of a rope of which the circumference is 20cm?

27. In a park is a fountain whose basin is 75m in circumference. What is the diameter of the basin?