Find the difference in time between : 3. Washington and Peking. 4. New York and San Francisco. 7. San Francisco and Berlin. 294. The difference in time between two places is 5 hrs. 30 mins. 25 secs. What is the difference in longitude? 5 hrs. 30 mins. 25 secs. 15 Since there are 15 times as many degrees, minutes, and seconds of longitude as there are hours, minutes, and seconds of time, 15 times the number representing the difference in time will give the difference of longitude in degrees, minutes, and seconds. EXERCISE 189.- WRITTEN 1. The difference in time between two places is 10 hrs. 16 mins. 24 secs. What is the difference in longitude? Find the difference in longitude between the following places and Greenwich, the difference in time being: 2. Athens, Greece, 1 hr. 34 mins. 54.9 secs. E. 5 hrs. 53 mins. 20.7 secs. E. 3. Calcutta, 4. Chicago, 5 hrs. 50 mins. 26.7 secs. W. 5. St. Petersburg, 2 hrs. 1 min. 13.5 secs. E. 6. What is the difference in longitude between St. Petersburg and Chicago? 7. When it is noon at Greenwich, it is 6.09 A.M. at Chicago. What is the longitude of Chicago? 8. When it is 6.09 A.M. at Chicago, it is 3.50 A.M. at San Francisco. What is the difference in longitude? STANDARD TIME 295. To use the exact sun time for each place brings about so many complications that another method has been devised by which the world is divided into 24 time belts, all places within the same belt using the same time. The time meridians of the time-belts of the United States are those of 75°, 90°, 105°, and 120°, as is shown in the accompanying map. Accordingly, the United States and Canada are divided into four belts extending north and south. All places in the same belt have the same time regardless of their exact longitude. In practice, these belts do not have regular boundaries; but the points of change are determined rather by the position of important cities. Time determined in this manner is known as Standard Time. EXERCISE 190.- ORAL 1. When it is noon at Greenwich, what time is it at New York, estimating the longitude at New York as 75°? 2. When it is 6 A.M. at New York, what time is it at Chicago? At Denver? At San Francisco ? EXERCISE 191.- WRITTEN 1. What is the difference between standard and local time at Chicago? 2. The longitude of Pittsburg is 80° 2' 0". What is the difference between standard and local time there? 3. What is the difference between standard and local time at New Orleans, longitude 90° 3′ 28.5′′ ? 4. The longitudes of St. Louis, Richmond, Denver, and Boston are respectively: 90° 15′ 15′′ W., 77° 26′ 4′′ W., 104° 59' 33" W., 71° 3' 30" W. At what time, standard, will an electric time signal sent from Washington at noon reach them? At what local time? REVIEW PROBLEMS EXERCISE 192.- WRITTEN 1. How many barrels of water will a trough hold, if it is 7 ft. long, 2 ft. wide, 16 ins. deep? 2. If a windmill pumps 2 gals. and 3 qts. each minute and pumps 4 hrs. in a day, how many cows will it supply if each cow consumes 1.5 cu. ft. of water daily? 3. How many pounds of water does each cow consume if one gallon weighs 8.35 lbs.? 4. A pound of timothy seed contains 1,170,500 seeds. Sowing 16 lbs. to the acre, how many seeds are sown to the acre? How many seeds are there in an ounce? 5. What is the value of a rectangular field 23 chs. 2 rds. 17 lks. 6 ins. long by 17 chs. 3 rds. 13 lks. 7 ins. wide at $37.50 an acre? 6. There are 15 steps on the hall stairs. The tread is 12", the rise 71". What will sufficient stair carpet cost at 62 cts. a yard, allowing 1 extra carpet for the projection of the tread? 7. In raising Irish potatoes three grades of seed were used: 1st, seed from the best hills to be found; 2d, seed from ordinary hills; 3d, seed from the very poor hills. The yields for each 100 hills planted with these seed were: ordinary seed 136 lbs. 14 ozs., best seed 172 lbs. 8 ozs., poor seed 75 lbs. 10 ozs. What was the average yield per hill? What was the increase in yield from seed No. 1 over that of No. 2? Of seed No. 2 over seed No. 3? 8. Sprayed grapes yielded 4 lbs. 5.8 ozs. to the row. Unsprayed grapes yielded 1 lb. 1.5 ozs. to the row. was the gain per row in pounds from spraying? What 9. Sprayed grapes yielded 3 lbs. 4.3 ozs. more per row than unsprayed grapes. What was the difference in yield on 177 rows? 10. Western Yellow Pine in Colorado, 20 years old, measured 1.2 ins. in diameter; at 30 years, 2.9; at 40, 4.9; at 50, 6.8; at 60, 8.6; at 70, 10.2; at 80, 11.7; at 90, 12.8; at 100, 13.8; at 110, 14.7; at 120, 15.5. What was its circumference at each of these ages? How much did the diameter increase from the fourth to the fifth decade? How much the circumference? How much did both the diameter and the circumference increase from the eleventh to the twelfth decade? 11. An ordinary milk pail is 114 ins. in diameter at the top; another pail has an opening only 7 ins. in diameter. What is the difference in the areas of the openings? If seven billion bacteria fall into the milk in the first pail in 15 mins., at the same rate how many would fall into the other pail in the same time? 12. Planting 7 ozs. of tomato seeds to the acre, how many pounds are needed for 19 A.? 13. Sowing 3 pks. of cow-peas to the acre, how many bushels of seed are needed for 40 A.? 14. Bordeaux mixture consists of 5 lbs. of bluestone, 5 lbs. of lime, and 50 gals. of water. Applying this to potatoes at the rate of 150 gals. of mixture to the acre, for each application, and making 3 applications: a. How many gallons will be needed on 40 A.? b. How many barrels? c. What will the bluestone cost at 6 cts. a pound? d. What will the lime cost at 14 cts. a pound? 15. To produce 1 T. of oats requires 376 T. of water. How many cubic feet of water are needed? How many barrels? How many hogsheads? How many quarts? 16. To produce a ton of wheat requires 338 T. of water. Solve for all the items of the last problem. 17. To produce a ton of dry matter, the average crop plant requires 325 T. of water. Solve as in problem 15. |