=

6 pt. 6÷6 = 1. Write the 1 in the result. Result,

(4) 3 qt. 4 bu. 2 pk. 4 qt. 1 pt.

2. Subtract 15 bu. 1 pt. from 18 bu. 1 pk. 5 qt.

3. From 4 cwt. 38 lb. take 1 cwt. 49 lb.

4. From 6 mi. 85 ch. 1 rd. take 4 mi. 75 ch. 4 rd.

5. Multiply:

(1) 24 bu. 5 qt. by 16.

(2) 26 sq. yd. 6 sq. ft. 14 sq. in. by 9.

(3) 6 lb. 3 oz. 17 pwt. 20 gr. by 7.

(4) 14 yr. 9 mo. 7 da. by 14.

6. Divide:

(1) 112 T. 16 cwt. 59 lb. by 7.
(2) 65 gal. 2 qt. 1 pt. by 7.
(3) 48 bu. 3 pk. 6 qt. by 9.

(4) 72 yr. 9 mo. 20 da. by 12.

7. How many cups, holding one half pint each, can be filled from a coffee urn holding 2 gal. 3 qt. 1.5 pt.?

8. What will be the cost of 3 T. 6 cwt. 27 lb. of coal at $4.75 a ton?

9. What is the difference between a half of a foot square and a half of a square foot?

10. What is the difference between 6 dozen dozen and a half a dozen dozen?

11. Reduce 4 hr. 15 min. to the decimal of a day.

12. A man wishes to put 116 bu. 1 pk. 4 qt. of wheat into sacks that shall contain 2 bu. 1 pk. 4 qt. each. How many sacks will be required?

13. How many steel rails 30 feet long are needed to build 5 miles of railroad?

14. At $3.40 per square, what will be the cost of tinning both sides of a roof 40 feet in length, whose rafters are 20 ft. 6 in. long?

15. What part of an acre is a plot of ground 118 yd. long and 80 ft. wide?

16. How many minutes in the year 1904?

17. How many seconds in July?

18. In 10° 15′ 25′′, how many seconds?

19. If a bale of cotton weighs 493 pounds, what will 6 bales cost at 10 cents a pound?

20. A parlor is 34 ft. long and 16 ft. 8 in. wide. What will it cost to cover the floor with Brussels carpet yd. wide, at $2.625 per yd.?

21. A farmer has three meadows. From the first, he raised 12 T. 17 cwt. 16 lb. hay; from the second, 14 T. 5 cwt. 4 lb.; and from the third, 7 T. 8 cwt. 13 lb. He reserved for his own use 12 T. 5 cwt. 8 lb., and sold the remainder at $18.00 per ton. How much did he receive?

22. A milkman adulterated 32 gallons of milk by adding a pint of water to every gallon of milk, and sold the entire quantity at the rate of 8 cents a quart. How much more

than the correct amount did the milkman dishonestly obtain?

VIII. LONGITUDE AND TIME

219. A meridian (Latin, meridianus, pertaining to midday) is an imaginary line extending due north and south from pole to pole.

220. A prime meridian is a meridian chosen as a standard from which to reckon longitude.

NOTE.—On October 1, 1884, a Prime Meridian Conference was held in Washington, and at this meeting the meridian extending through the Royal Observatory at Greenwich (a suburban city 5 miles southeast of London) was recommended to be the prime meridian. This recommendation has been adopted by nearly all the civilized nations. France still uses the meridian extending through the observatory at Paris.

221. Longitude (Latin longus, long) is the distance (expressed in circular measure) east or west from the prime meridian.

222. Since the earth makes one complete rotation upon its axis in 24 hours, every point on the earth's surface passes through 360° in that length of time. Therefore,

360° of longitude correspond to 24 hours of time.

Hence, the difference in longitude in degrees, minutes, and seconds is 15 times the difference in time in hours, minutes, and seconds, respectively.

223. Longitude and time gives rise to two cases:

1. To find the difference of longitude between two places when the difference of time is given.

2. To find the difference of time between two places when their longitudes are given.

EXAMPLES

1. The difference between the local times of two places. is 4 hr. 3 min.: what is the difference of longitude between them?

SOLUTION:

1. Since 1 hr. of time corresponds to 15° of longitude,

66 66

66

correspond 60°

66

66

2. ... 4
3. Since 1 min. of time corresponds to 15' of longitude,

From this solution we may obtain the

RULE. To find the difference of longitude between two places when the difference of time is given:

Multiply the difference of time by 15, and call the result degrees (°), minutes ('), and seconds (") of longitude.

2. The difference of longitude between two places is 28° 40′ 30′′: what is the difference of time?

SOLUTION:

1. Since 1° longitude corresponds to 4 min. of time,

5. But 112 min. + 162 sec. = 1 hr. 54 min. 42 sec.

.. The difference of time is 1 hr. 54 min. 42 sec.

When the solution is understood, the pupil should be allowed to use the following

RULE. To find the difference of time between two places when the difference of longitude is given:

Divide the difference of longitude by 15, and call the result hours, minutes, and seconds of time.

Exercise XXVII

1. The longitude of Denver is 105° 4′ W.; the longitude of Vicksburg is 90° 54′ W.; find the difference of sun-time.

2. The longitude of Berlin is 13° 23′ 45′′ E.; the longitude of New Orleans is 90° W.; find the difference of suntime.

QUESTION. In problem 2, why do you add the numbers to get the difference of longitude?

3. The longitude of Austin is 97° 44′ W.; the longitude of St. Louis is 90° 14′ W.; find the difference of sun-time.

4. The longitude of San Francisco is 122° 24′ 30′′ W.; the longitude of Honolulu, Hawaii, is 157° 52′ W.; find the difference of sun-time.

5. The longitude of Savannah, Ga., is 81° 5' 26" W., and the difference in sun-time between Savannah and El Paso, Tex., is 1 hr. 41 min. 30 sec. What is the longitude of El Paso?

6. If, at the next presidential election, the voting begins at sunrise, how much sooner will the polls open at Portland, Me., 70° 15′ 45′′ W., than at Portland, Oregon, 122° 27′ 30′′ W.?

7. A ship at sea finds that it is 3 hr. 34 min. p. m. by its