The sign is prefixed to the latitude, or declination, of the Sun, or other heavenly body, when north, and the sign when south; but the former prefixed to the hourly motion of the Moon in latitude indicates that she is approaching, and the latter that she is receding from, the north pole of the ecliptic. The letters M. A., m. a., denote Morning and Afternoon. Dominical Letter, CHRONOLOGICAL CYCLES. G| Solar Cycle, 16 12 Roman Indiction, . 13 6568 Lunar Cycle, or Golden Number, 13 | Julian Period,• [The anniversaries marked with an asterisk (*) are to be strictly observed.] 16th, *Second Feast, or Morrow of the Passover, Apr. 4, " 66 22d, *End of the Passover,. "18th, Lag Beomer, 66 6th, *Feast of Weeks or Pentecost, Thammuz begins, 66 17th, Fast for the taking of the Temple, "9th, Fast for the burning of the Temple, 5616 Tisri begins, *Feast for the New Year, "10th, *Fast of the Reconciliation or Atonement, Apr. 10, " Apr. 19, " May 6, " May 18, " May 23, " July 3, " Year. Names of the Months. 5616 Tisri 16th, *Second Feast of the Huts, 66 "21st, Feast of Palms or Branches, 66 22d, *End of the Hut or Congregation Feast, "23d, *Rejoicing for the Discovery of the Law, Marchesvan begins, Chisleu begins, 66 25th, Consecration of the Temple, The Jewish year generally contains 354 days, or 12 lunations of the Moon; but in a cycle of 19 years, an intercalary month (Veader) is 7 times introduced, for the purpose of rendering the average duration of the year nearly or quite correct. The Mahometan Era dates from the flight of Mahomet to Medina, July 16th, A. D. 622. The Mahometan year is purely lunar; it consists of 12 synodical periods of the Moon, or of 354 days 19 times in a cycle of 30 years, and of 355 days 11 times. The average length of this year is therefore 35411 days, which differs only thirty-three seconds from the truth; a degree of exactness that could only have been attained by a long series of observations. But as no allowance is made for the excess of 11 days in the length of a tropical year over the time of 12 revolutions of the Moon, it is obvious that once in about 33 years the above months will correspond to every season and every part of the Gregorian year. HEIGHT OF THE GREATEST OR SPRING TIDES IN 1855. Computed by the Formula of Laplace (Mécanique Céleste, Vol. II. pp. 289, Paris ed., and [2858] Bowd. ed.). The unit of altitude at any place is the height at that place of that tide which arrives about a day and a half after the time of New or Full Moon, when the Sun and Moon, at the moment of conjunction or opposition, are at their mean distance from the Earth, and in the plane of the celestial equator. This unit of altitude, which must be derived from observation for each place, multiplied by the quantities in the above table, gives the height of the spring tides at that place during the present year. By the above table it appears that the highest tides of 1855 will be those of Feb. 18, March 19, April 17, Aug. 28, Sept. 27, and Oct. 26. The actual rise of the tide, however, depends so much on the strength and direction of the wind, that it not unfrequently happens that a tide, which would, independently of these, have been small, is higher than another, otherwise much greater. But when a tide, which arrives when the Sun and Moon are in a favorable position for producing a great elevation, is still further increased by a very strong wind, the rise of the water will be uncommonly great. The formula from which these tides were computed is, however, strictly true only for Brest and its vicinity, and must be regarded as a very uncertain approximation for the coast of the United States. 19 67 51 48 19 53 7 Su. 7 30 4 44 7 25 4 49 7 19 4 54 7 4 5 10 6 57 5 16 7 16 4 57 50 19 55 rises. sets. rises. sets. rises. sets. rises. sets. rises. sets. rises. sets. 1 M. 7 30 4 38 7 25 4 43 7 19 2 Tu. 30 4 Th. 5 F. 6 S. 49 7 3 5 5 6 56 5 12 7 15 4 52 11 sa 3 56 13 15 53 3 57 13 16 54 8 3 57 14 16 55 0 51m 3 4 57 4 54 18 59 3 14 57 20 15 14 Su. 7 27 4 51 7 23 4 56 7 18 5 17 3 5 16 6 57 5 22 7 15 5 4 27 52 16 Tu. 27 17 W. Th. 25 21 58 57 17 58 17 21 Su.7 24 5 0 7 19 5 4 7 15 5 9 7 15 22 6 55 5 28 7 12 5 11 24 W. 25 Th. 21 26 F. 27 S. 19 58 4 13 H2345 12 11 57 17 16 58 3 53 57 18 16 59 4 34 57 19 16 5 0 5 15 57 19 16 1 5 57 3 15 57 21 15 23 2 6 41 7 29 28 Su. 7 18 5 8 7 14 5 12 7 10 5 17 6 58 5 29 6 53 5 34 7 8 5 19 |
