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ECLIPSE

slightly less in former centuries, and will increase a little in a.d. 733, August 14 (annular). A.D. 1133, August 1, C. 764, June 4 (annular). 1140, March 20, C. the future owing to the acceleration of the moon’s motion. 878, October 29, C. 1185, May 1, C. When this motion is assigned to the circle eclipses will always 1191, June 23, C. (annular). 885, June 15. take place at one or the other of these 223 points, but will, 1330, July 16. 1023, January 24. Besides these, the tables show that the shadow of the moon of course, be confined to those which lie near the moon’s passed over some part of the British Islands on 1424, June 26 ; node. The latter will now move over the system of points 1433, June 17 1598, March 6 1652, April May 2 ; at the rate of 0° 476 per period. This will carry the node 1724, May 22. The next dates are 1927, June 829,; 1715, when a barely from one conjunction-point to the next in about 61 years. total eclipse will be seen soon after sunrise in the northern We may classify eclipses according to the conjunction- counties near the Scottish Border, and 1999, August 11, when point at which they occur. As any one such point slowly the moon’s shadow will graze England at Land’s End. approaches the node the successive eclipses, separated by an We give below, in tabular form, a list of the principal interval of one Saros, which occur at that point, will fall total eclipses between 1800 and 1970, omitting a few continually nearer the node until the conjunction-point visible only in the extreme polar regions, and £C]Jpses of passes it, near which time they will be central. After some others of which the duration is very short, the 19th passing the node a certain distance the eclipse will cease to The eclipses are classified in the table according and 20th be central, and become partial until at length the distance to their position in the eighteen-years period,centunesof the point from the node will be such that the series so that the table shows the successive eclipses occurwill cease. The entire duration of each series is more ring at this interval. In this way it is possible for the than a thousand years. The introduction of the period in reader to continue the table, with a considerable degree of question would have no special significance but for one approximation, for several periods, wliile the law of recurimportant circumstance. It happens that the lapse of one rence and the gradual change in the character of the eclipse Saros brings together not only the sun and moon, but are made evident at sight. The .first column gives the date approximately the lunar perigee and the mean anomaly of of the point on the earth’s surface at which the eclipse is the sun. The change in the former is less than three central at noon. The next two columns give the position degrees, in the latter between ten and eleven degrees. of this point to the nearest degree. As the date in the The character of an eclipse, whether annular or total, and, first column changes at 180° long, from Greenwich, the if total, the duration of the total phase, depend on the integer dates are not at equal intervals, and therefore the position of the lunar and solar perigees relatively to the con- fourth column shows the Greenwich astronomical time of junction-point. It follows that each recurring eclipse will conjunction in longitude. The next column gives the be of the same general character as that which preceded it. duration of the total phase at the noon-point; this is someIf the duration of totality of the latter is remarkably long, times 0mT less than the greatest duration. The eclipses the same will be true of the recurring eclipse. This fact of each period occur near the same node of the noon, which enables us, by the aid of suitable tables, to select almost is indicated at the head of the series. By the central date of the series is meant that date when an eclipse occurred, in at sight eclipses of long duration in the past or future. The following is a brief chronological enumeration of the mean, nearest to the node. This is, of course, one of those total eclipses of the sun which are of interest, either the dates of the series. from their historic celebrity or the nature of the Total Eclipses of the Sun, 1800 to 1970, classified by the Years Period.1 eclTses derivedthe from them. era In numbering ec pses. conclusions yearg before Christian the astronomical nomenclature is used, in which the number of the year is one less than that used by the chronologists. The Chinese eclipses are passed over, owing to the generally doubtful character of the records pertaining to them. 762 b.c., June 14 ; a total eclipse recorded at Nineveh. Computation from the modern tables shows that the path of totality passed about 100 miles or more north of Nineveh. 584 b.c., May 28 ; the celebrated eclipse of Thales. An account of this eclipse will be found in the article Thales (Ency. Brit. vol. xxiii.). 556 B.c., May 19 ; the eclipse of Larissa. The modern tables show that the eclipse was not total at Larissa, and the connexion of the classical record with the eclipse is doubtful. 430 b.c., August 3 ; eclipse mentioned by Thucydides, but not total by the tables. 399 b.c., June 21 ; eclipse of Ennius. Totality occurred immediately after sunset at Rome. The identity of this eclipse is doubtful. 309 b.c., August 14 ; eclipse of Agathocles. This eclipse would be one of the most valuable for testing the tables of the moon, but for an uncertainty as to the location of Agathocles, who, at the time of the occurrence, was at sea on a voyage from Syracuse to Carthage. Ginzel (Spczieller Kanon der Finsternisse) has collected a great number of passages from classical authors supposed to refer to eclipses of the sun or moon, but the difficulty of identifying the phenomenon is frequently such as to justify great doubt as to the conclusions. In a few cases no eclipse corresponding to the description can be found by our modern table to have occurred, and in others the latitude of interpretation and the uncertainty of the date are so wide that the eclipse cannot be identified. Of mediaeval eclipses we mention only the dates of those visible m England, referring for details to the works mentioned in the bibliography. The letter C following a date shows that the eclipse is mentioned in the Anglo-Saxon Chronicles. The dates in question are a.d. 538, February 15, C. (partial). a.d. 603, August 12. 639, September 3. 540, June 12, C. (partial). 664, May 1, C. 594, July 23.

DatePoint. at Noon-

Central Noon. at Greenwich ofM.T. Conj. Total Lat. i Long. in Long. Phase

Regions swept by Shadow.

Series I. Ascending Node ; Central date, 1731, Jan. 8. d. h. m. Pacific Ocean, Mexico. 136 W 21 9 20 1803, Feb. 21 Indian and Pacific Oceans. 96 E 3 17 50 1821, Mar. 4 South America, Africa, Egypt. 31W 15 2 14 1839, Mar. 15 Pacific Ocean, Mexico. 155 W 25 10 30 1857, Mar. 25 Indian Ocean, Siam, Pacific. 83 E 5 18 36 1875, Apr. 6 Venezuela to West Africa. 37 W 16 2 35 1893, Apr. 16 Australia, Polynesia. 155 W 28 10 26 1911, Apr. 28 Sumatra, Malacca, Philippines. 89 E 8 18 8 1929, May 9 Argentina, Paraguay, Central 25 W 20 1 44 1947, May 20 Africa. Pacific Ocean. 1965, May 30 4 S 137 W 30 9 14 Series II. Descending Node ; Central date, 2183, March 23. Pacific Ocean, Chile, Argentina. 1804, Aug. 5 38 S 66 W 5 4 6 Australia, Pacific Ocean. 1822, Aug. 16 36 S 176 W 16 11 22 Africa, Indian Ocean. 1840, Aug. 27 34 S 72 E 26 18 45 Peru, Southern Brazil, Uruguay. 1858, Sept. 7 33 S 41 W 7 2 16 Pacific Ocean. 1876, Sept. 17 33 S 156 W 17 9 54 East Africa, Indian Ocean. 1894, Sept. 29 34 S 86 E 28 17 34 Colombia, Ecuador, Brazil. 1912, Oct. 10 35 S 33 W 10 1 41 Pacific Ocean, Patagonia. 9 47 1930, Oct. 21 36 S 155 W 21 Central Africa, Congo. 82 E 31 18 3 1948, Nov. 1 37 S 43 Bolivia, Argentina, Brazil. W 12 2 27 1966, Nov. 12 33 S Series III. Descending Node ; Central date, 1626, Feb. 26. New England, Atlantic, Spain. 66 W 16 4 22 1806, June 16 42 N 175 Pacific Ocean, Japan, China. W 26 11 43 1824, June 26 47 N Spain, France, Russia to China. 77 E 7 19 2 1842, July 8 51 N 31 British America, Spain, Egypt. W 18 2 21 1860, July 18 56 N 139 United States. 1878, July 29 60 N 112 WE 298 179 402 North Europe, Siberia, Japan. 1896, Aug. 9 65 N Scandinavia, Russia, Asia Minor. 0 27 1914, Aug. 21 1 71 N 2 E 21 Canada, East United States. 1932, Aug. 31 78 N 105 W 31 7 55 i In addition to these, a series will commence 1938, May 29, and t>e continued 956, June 8, 1974, June 20. &c., with a duration of 4 or 5 m., but will ne dsible only in the Southern Hemisphere.