Exercise 2 (Refer to figure, Sec. 11, in answering the questions of this exercise; answer as many as possible orally.) State how many degrees and in what direction by the shorter arc is: If A and B stand for two cities, and A is west of B, A's time is 1 hour earlier (slower) than B's for every 15° that A is west of B. If A and B stand for two cities, and B is east of A, B's time is 1 hour later (faster) than A's for every 15° that B is east of A. What is the time at: 17. 90° E. when the time at 30° E. is 6 P.M.? On what meridian is the time: 23. 3 P.M. when the time at 60° W. is 6 P.M.? Illustrative Examples The longitude of Chicago is 87° 34' 8" W., and of Boston 71° 3' 30" W. When it is 10 A.M. at Boston, what is the time at Chicago? 87° 34' 8" W. is the longitude of Chicago. 71° 3' 30" W. is the longitude of Boston. of the number of degrees, minutes, and seconds in the difference of longitude of two places equals the number of hours, minutes, and seconds in the difference of their time. 15)16 30 38 .. 1 hr. 6 min. 2.5 sec. is the difference of time, correct to the nearest tenth of a second. The difference of time is subtracted from the time of Boston, since Chicago is west from Boston, and, therefore, has earlier time than Boston. 2. When it is 3 hr. 45 min. A.M. Wednesday at Paris, longitude 2° 20′ 30′′ E., it is 9 hr. 11 min. 57.5 sec. P.M. Tuesday at Omaha. Find the longitude of Omaha. 15 times the number of hours, minutes, and seconds in the difference of time of two places equals the number of degrees, minutes, and seconds in the difference of their time. Since the time is later at Paris than at Omaha, Omaha must be west of Paris. 98° 15' 37.5" is the distance of Paris from Omaha. 2° 20′ 22 "' is the distance of Paris east from the prime meridian. 95° 55′ 15.5" is the distance of Omaha west from the prime meridian. ... 95° 55′ 15.5" W. is the longitude of Omaha. 1. The longitude of Haven, 72° 55' 34" W. the time at St. Louis? Exercise 3 St. Louis is 90° 15′ 16" W., and of New 2. The longitude of Philadelphia is 75° 9' 5" W., and of San Francisco 122° 26' 15" W. What is the time in Philadelphia when it is noon at San Francisco? 3. The longitude of Rome is 12° 27' 14" E., and of New York 74° 3" W. When it is 11 P.M. Tuesday at New York, what time is it at Rome? 4. The time at Galveston, Texas, is 6 hr. 9 min. 9.9 sec. earlier than the time on the prime meridian. What is the longitude of Galveston, Texas? 5. The longitude of Jerusalem is 35° 32' E., and of Edinburgh is 3° 12' W. When it is 6 A.M. at Edinburgh, what is the time at Jerusalem? 6. When it is 1 P.M. at Oxford, England, it is 1 hr. 58 min. 45.3 sec. P.M. at Berlin. If the longitude of Oxford is 1° 15' 6" W., what is the longitude of Berlin? Standard Time 12. For the convenience of business in general and of railroads especially, a system of standard time has been adopted; it was put in force in the United States on Sunday, Nov. 18, 1883. This system practically divides the country into four belts and adopts the local time of a meridian in each belt as the common time for all places in that belt. 13. The standard belts are: (1) Eastern, whose standard time is the local time of the 75th meridian. (2) Central, whose standard time is the local time of the 90th meridian. (3) Mountain, whose standard time is the local time of the 105th meridian. (4) Pacific, whose standard time is the local time of the 120th meridian. 14. It is evident that within each of these belts the standard time is uniform, and that the time of each belt differs from that next to it by exactly one hour. NOTE 1. It was intended that each standard meridian should govern the belt 7 degrees on each side of it, but there have been some slight variations from this, due to the fact that railroad companies often change time at important railroad centers near a boundary when such centers are not located on the boundary. NOTE 2. The Eastern belt includes all territory between the Atlantic and an irregular line drawn from Buffalo to Central Junction, Ga., the latter city being its southernmost point. The Central belt includes all the territory between this eastern line and another irregular line drawn from Bismarck, N.D., to El Paso, Tex. The Mountain belt includes all the territory between the last named line and nearly all the western boundaries of Idaho, Utah, and Arizona. The Pacific belt includes all the territory of the United States between the western boundary of the Mountain belt and the Pacific coast. NOTE 3. It is evident that in any belt the local time of places east of the standard meridian is faster, and that of places west slower, than the standard time. Exercise 4 1. When it is noon in the Eastern belt, what is the time in each of the other belts ? 2. When it is noon by Mountain time, what is the time in each of the other belts ? 3. Find the difference between the standard time of New York and that of Chicago, longitude 87° 34' 8" W. 4. In traveling from Philadelphia to San Francisco would a traveler find his watch too slow or too fast, and by how many hours? 5. How much slower is local, or sun, time than standard, or railroad, time at longitude 77° 30′ W.? 6. When it is noon at the 75th meridian west, is the local time of places that are east of the 75th meridian and in the Eastern belt later or earlier than noon? 7. A traveler that left San Francisco at noon Sunday, Pacific time, arrived in New York at noon Friday, Eastern time. How long did it require to make the journey? PUBLIC LANDS 16. Most of the public lands north of the Ohio River and west of the Mississippi are laid out by lines running north and south and east and west. Principal Meridian Base Line Fig. 1. A 17. The method is to select a point in a tract and through it establish a north and south line called a principal meridian, and an east and west line called a base line. Lines are run parallel to the principal meridian and to the base line at intervals of 6 miles, thus dividing the tract into townships. that are approximately 6 miles. square. A series of townships ex |