27. In a city in Greece, 800 private lights burning a certain kind of gas are in use. If each jet consumes 15 liters of gas per hour and burns on an average 4 hours per day, how much gas is consumed in the city per week?

28. The substance from which this gas is made gives out 300 liters of gas per kilo. How many boxes containing 50

kilos each are used per week?

29. A quart of water is less than a liter, but if frozen will make more than a liter of ice. Find how many cubic centimeters more, if water expands of its volume in freezing.

30. Find the cost of 17 metric quintals of chestnuts at 15 francs per sack of 100 kilos.

31. The length of a new French locomotive is 16.2 m. How much longer, to the nearest inch, is it than a large English locomotive whose length is 41 ft. 4 in.?

32. A shipment of coffee from Bahia, Brazil, to Bordeaux, France, consisted of 500 bags holding 60 Kg. each. Find the cost for freight in francs at 30 francs per 900 Kg.

33. In a quarry in Saxony an undercut resulted in the fall of 58,000 cu. m. of stone. Find the weight of the stone in metric tons, if its specific gravity was 2.7.

34. Greece sent to Great Britain one year 64,000 metric tons of currants, and to Holland and the United States and as much, respectively. Express these quantities in short tons.

16

35. The Bank of France pays 3437 francs for 1 kilogram of fine gold. Find, to the nearest cent, the equivalent price per troy ounce.

36. At a Berlin motor boat exhibit, an American exhibitor paid an entrance fee of 100 marks, and rented a floor space of 4 square dekameters at 10 marks per square meter. Find his

expense to the nearest cent.

PRACTICAL MEASUREMENTS

MEASURES AND EQUIVALENTS

300. In delicate weighing, a small unit of weight called a grain, originally the weight of a grain of wheat, is used.

The grain is the same for both avoirdupois and troy weight, and is therefore the connecting link between thẻm.

The apothecaries' ounce is the same as the troy ounce. Complete tables will be found on pages 345-347.

301. Water in large quantities is measured by the barrel (bbl.) of 31 gallons, by the cubic foot, and by the thousand or million gallons.

A gallon is equivalent to 231 cu. in.; hence, 1 cu. ft. (1728 cu. in.) 1726 gal. = 7.48+ gal., or nearly 71 gal.

=

302. In ordinary calculations, the weight of a cubic foot of water is taken as 621 1b., or 1000 oz.

Then since 1 gal. (231 cu. water weighs 1 of 621 lb.

1768

=

303. A bushel is equivalent

= 1728

in.) 231 cu. ft., a gallon of 8.355+ lb., or about 8 lb.

to 2150.42 cu. in., but for all practical purposes it is considered sufficiently accurate to take 1 cu. ft. (=2160 cu. in.) as the equivalent.

304. Hereafter, unless the contrary is expressly stated, the following measures and approximate equivalents should be used:

305. 1. A one-cent copper piece weighs 48 grains. If I get $35 in new cent pieces, how many pounds do I have to carry?

2. One hundred cartridges for the American military rifle weigh 6 lb. 7 oz. 52 gr. The same number of cartridges for the German rifle weigh 6 lb. 2 oz. 149 gr. grains of each kind of cartridge.

Find the weight in

The weight of the

How much more

3. A diamond carat is 3.168 grains. largest diamond in the world is 3025 carats. than 1 pounds avoirdupois does the diamond weigh?

4. A silver dollar weighs 412.5 grains, of which is pure silver. How many silver dollars must a silversmith melt to obtain 2 lb. 6 oz. 18 pwt. 18 gr. of pure silver?

5. If 420 tons of drinking water are consumed on a vessel during an Atlantic voyage, how many gallons are used? how many cubic feet?

6. A skating rink 75 feet by 216 feet was flooded with 2 inches of water. How many gallons were used? ́

7. How many gallons of water will the tank of a locomotive tender hold, if its capacity is 8125 cubic feet?

8. The cargo of grain from a vessel each 8 feet square and 90 feet deep. wheat did the vessel carry?

filled 12 elevator bins,

How many bushels of

9. Find the capacity in bushels of a Duluth grain elevator having 2,250,000 cubic feet of storage space.

Find the

10. The specific gravity of glass is about 2.76. weight of a piece of plate glass 12 in. by 10 in. by 1⁄2 in.

11 What is the specific gravity of paraffin, if a block 6 in. by 4 in. by 1 in. weighs 12 ounces?

12. The specific gravity of ice is .92. What must be the height of a room required to hold 184 tons of ice, making no allowance for packing, if the floor space is 20 feet square?

13. A cord of maple wood weighed 2814 pounds. If the specific gravity of the wood was .67, how many cubic feet of solid wood did the cord contain?

14. A body floating in water displaces its own weight of water. The steamship Baltic weighs 40,000 tons. How many cubic feet of fresh water would she displace? of salt water, specific gravity 1.03?

15. A double eagle weighs 21 pennyweights. Find to the nearest cent the value of 1 pennyweight of pure gold.

The value of a gold coin is the value of the gold it contains. U. S. gold coins are fine; British or sterling gold, 1 fine.

16. How many grains does a new quarter eagle weigh? 17. Find the weight of $1,000,000 in new U. S. gold coin. 18. The English mint is compelled to coin any gold offered it, returning 778. 101d. per ounce of sterling fineness. Show that the standard weight of a sovereign is 123.27447 grains. 19. Find the weight of £1,000,000 in sterling money.

20. A stamping press at the mint stamps 80 double eagles per minute. How many pounds of coin does it stamp per hour?

21. The weight of gold lost every year by wear, sinking of vessels, etc., is estimated at 193,704 ounces. How many eagles could be made from this amount? How much gold would be left over?

MEASURES OF TEMPERATURE

306. On a Fahrenheit thermometer, the one in common use in America, the freezing point of water is marked 32°, or 32 degrees, and the boiling point 212°. For ordinary purposes, however, thermometers are not marked as far

as the boiling point.

Since the difference between the freezing and boiling points of water, 212° - 32°, is 180°, one degree Fahrenheit is of this difference.

A more convenient system, in which this difference in temperature is divided into 100 degrees, from 0° at the freezing point to 100° at the boiling point, has been devised; but it is not yet in general use in America. It is called the centigrade system of measuring temperature.

Temperatures below 0° are marked with a minus sign, thus: 1°, - 3°.

= a change of 180°

180° F., a change of 1° C.

F., or of g° F.

A change of 1° F. a change of 100° C., or

180

of 5° C.

EXERCISES

307. 1. At 6 A.M. the temperature was -10° F., and at noon it was 22° F. Find the rise in temperature.

2. At 2 P.M. the temperature was 27° F., and at 9 P.M. it was 2° F. Find the fall in temperature.

3. How far below the freezing point of water is -16° F.?

4. In a freezing mixture composed of ice and salt, the temperature fell from +10° C. to 18° C. Express the fall in degrees centigrade.