THE

AMERICAN ALMANAC,

FOR THE YEAR

1861,

Being the latter part of the 85th, and the beginning of the 86th year of the Independence of the United States of America;

the 6574th year of the Julian Period;

the latter part of the 5621st, and the beginning of the 5622d year since the creation of the world, according to the Jews; the 2614th year (according to Varro) since the foundation of

Rome;

the 2608th year since the era of Nabonassar, which has been as-
signed to Wednesday, the 26th of February, of the 3967th
year of the Julian Period, which corresponds, according to
the chronologists, to the 747th, and, according to the astrono-
mers, to the 746th year before the birth of Christ;

the 2637th year of the Olympiads, or the first year of the 660th
Olympiad, beginning in July, 1861, if we fix the era of the
Olympiads at 775 years before Christ, or at or about the
beginning of July of the year 3938 of the Julian Period;
the latter part of the 1277th, and the beginning of the 1278th
year (of twelve lunations) since the Hegira, or flight of Ma-
homet, which, as is generally supposed, took place on the 16th
of July, in the year 622 of the Christian era.

6 Conjunction, or having the same Longitude or Right Ascension.

Quadrature, or differing 90° in

8 Opposition, or differing 180° in

66
66

The ascending, & the descending node.

4

CHRONOLOGICAL CYCLES, SIGNS OF THE ZODIAC, ETC. [1861.

The sign is prefixed to the latitude, or declination, of the Sun, or other heavenly body, when north, and the sign — when south. The letters M. A., m. a., denote Morning and Afternoon.

Dominical Letter,

Epact,

CHRONOLOGICAL CYCLES.

F | Solar Cycle,

18 Roman Indiction, .

Lunar Cycle, or Golden Number, 19 | Julian Period,

SIGNS OF THE ZODIAC.

'[The anniversaries marked with an asterisk (*) are to be strictly observed.]

16th, *Second Feast, or Morrow of the Passover, Mar. 27,
21st, *Seventh Feast,

66

Apr. 1,

66 6th, *Feast of Weeks, or Pentecost,

Thammuz begins,

17th, Fast for the taking of the Temple,. June 25,

"9th, Fast for the burning of the Temple,

66 "Elul begins,

5622 Tisri begins, *Feast for the New Year,

"2d, *Second Feast for the New Year,
"4th, Fast of Gedaljah,

Apr. 28, May 10, " May 15, "

66

May 16,

66

June 9,

66

"10th, *Fast of the Reconciliation or Atonement,

Sept. 20, "

Year. Names of the Months.

5622 Tisri 21st, Feast of Palms or Branches,

Sept. 25, 1861

"22d, *End of the Hut or Congregation Feast, "23d, *Rejoicing for the Discovery of the Law, Marchesvan begins,

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 354 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.

d. h.

0.83

HEIGHT OF THE GREATEST OR SPRING TIDES IN 1861.

Computed by the Formula of La Place (Mécanique Céleste, Vol. II. pp. 289, Paris ed., and [2858] Bowd. ed.).

Washington Mean Time of

New or Full Moon.

New Moon, Jan. 10, 10 A.

Full 66

26, 0 A.

0.98

New 66

Aug. 6, 8 M.
66 20, 7 M.

0.97

0.91

Sept. 4, 5 A.

1.08

18, 9 A.

0.88

Full 66

New 66

66 26, 9 M. April 10, 2 M.

1.16

New 66

66 18, 2 A.

0.83

Full 66

24, 5 A.

New 66

Full 66

May 9, 6 A.
24, 1 M.

0.78

Full

0.96

New 66

Full 66
22, 9 M.
New 66 July 7, 9 A.

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 1861 will be those of Feb. 23, March 26, April 24, Sept. 4, Oct. 4, and Nov. 2.

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.