HEIGHT OF THE GREATEST OR SPRING TIDES IN 1848. Computed by the Formula of Laplace, (Mécanique Celeste, 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 1848 will be those of March 7, April 5, May 4, September 14, October 14, and November 12. 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 anoth er, 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, sufficient, perhaps, to cause damage. 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. DARKNESS OF THE NIGHTS DURING THE YEAR 1848. For Boston, New York, Philadelphia, Washington, &c. The number of hours at the top of the page denotes the average time for the month from the end of the evening twilight to the beginning of the morning twilight. The dots in the table denote the hours of entire darkness, when there is neither sun, moon, nor twilight; and their disposition denotes the hours before or after midnight. Sun's upper limb rises and sets, (corr. for refract.) M. Time. High Water. M. Time. 20th day, 6h. 56 6 50.4 M. M. 7 19 4 49 4 50 7 45 19 51 45 19 51 1 S. rises. sets. rises. sets. rises. sets. rises. sets. rises. sets. 7 30 4 38 25 4 43 7 19 2 Su. 7 30 4 39 7 25 4 44 3 M. 4 Tu. 30 40 7 3 5 5 6 57 5 11 3 5 6 6 57 5 12 3 9 Su. 7 30 4 45 7 25 4 50 7 19 4 56 7 3 5 12 6 58 5 17 16 Su. 7 27 4 53 7 22 4 58 7 17 5 3 7 2 5 17 6 57 5 23 &c. 6 30m 4 10m 2 30m 23 24 25 25 11 31 26 27 29 10 6 10 40 30 Su. 7 16 5 10 7 12 5 14 7 8 5 18 6 57 5 30 6 52 5 35 Passage of the Meridian (mean time) and Declination of the Planets. 7 29a+14 47 7 14a+15 32 6 59a +15 18 6 45a +17 7 8 50 -16 12 8 54 Dec. о 11 34m-22 13 -21 38 9 10m-21 3 6 32a +17 56 0 4 -22 48 11 54m-22 41 11 44m-22 29 11 24m-21 51 2 10 -12 48 1 58a-12 22 1 45a-11 51 1 32a-11 18 1 19a-10 41 4 16m-18 26 3 55m -18 14 3 34m-17 53 3 11m +13 49 2 48m-16 21 4 3 +22 53 10 39a23 3 5 1912 40 5 6 +12 50 4 46 +22 39 0 4 22 4511 32a +18 4 4 24 -17 15 +13 23 0 32 Days of Month. EJ+UKO+0+α Moon Souths. Mean Time. 4 1a-10 6 3 39a H6 115 4 5 48 Moon + 5 65 24 h. m. 18 3m 2 37m S. 8 49m 3 33m 3 31m rises. rises. h. m. + 5 8 5 ∙1 N. Or's, &c. rises. 6 48a + 5 11 4 395 15 PHENOMENA AND OBSERVA- 8 52a 1st Sunday after Epiphany. 6 10 21m 80 6 10 2a 6 9 7 58m 6vm 10 2 4m in 8 10 7 31mh 3 30m 3 22m 3 11m 3 11m 3 sm 2d Sunday after Epiphany. 4 8 10 9 313 in Aphelion. 5 5 11 0 52axOphi. *0 31 N. rises. 12 4 47a6H h. m. h. m. h. m. 2 24m 2 22m 3938 2 9 28m 69 750 5 9 17a 8 38a 8 41a 8 43а 8 48a 77 21a 18 10 58 1911 52 20 8 4 32 4 24 5 30 4 11 4 11 5 9 rises. 0 25m 0 23m 0 20m 0 14m 0 12m 27 2 25m 6 1 21 1 18 1 17 1 8 1 5 29 0 52m Sup. 6 ¥O S. 7 28m 2 17m 2 14m 2 11m 2 0m 1 57m 4th Sunday after Epiphany. 31 8 17 3 14 3 10 3 6 2 54 2 50 31 8 6mgr. Hel. Lat. S. 10 29 11 20 22 11 40m |