網頁圖片
PDF
ePub 版

II. LATITUDE AND LONGITUDE.

[graphic]

LATITUDE AND LONGITUDE

Of the Principal Points on the Pacific Coast, determined by George Davidson, U. S. Coast Survey.

[ocr errors]
[ocr errors]
[ocr errors]
[ocr errors]
[ocr errors]
[ocr errors]
[ocr errors]
[ocr errors]

NOTE.-Primary astronomical

stations in SMALL CAPITALS; the series of observations at these sta

tions extend through not less than two or three lunations. Positions determined by trigonometrical connection with astronomical stations, in Italics. All other determinations by chronometric connecThe localities of the astronomical stations and observatories can be more definitely determined by tion with primary astronomical stations for longitude, and independent observations for latitude. reference to the published maps, etc.

III.-TIDES AT SAN FRANCISCO, CAL.

[By Prof. A. D. Bache, Superintendent U. S. Coast Survey.]

Besides the ordinary changes in the time and hight of the tides known to all navigators, it is important to note the following, generally applicable to the Western Coast, and particularly to San Francisco Bay. They relate to peculiarities in the tides which occur on the same day, the necessity for knowing which is shown by the fact that a rock having three and a half feet of water upon it at low tide, may, on the same day, at the succeeding low water, be awash:

1. The tides at Rincon Point, in San Francisco Bay, consist generally of a large and small tide on the same day; so that of two successive high waters in the twenty-four hours, one is much higher than the other, and of the two successive low waters, one is much lower than the other.

2. The difference in hight of two successive tides, either high or low waters, varies with the moon's declination. When the declination is nothing, the difference is nothing or very small. When the declination is greatest, whether North or South, the difference is greatest. When the moon's declination is nearly nothing, the intervals between two successive high, or two successive low waters, are nearly twelve hours, and differ most from this when the moon's declination is greatest.

3. The inequalities in the hights of successive low waters are more considerable than those of successive high waters; while, on the contrary, the inequalities in the times of high water are more marked than those of low.

4. The average difference between the hights of two successive high waters is one foot four and a half inches, and of two successive low waters two feet four inches. The average difference of these same hights, when the moon's declination is greatest, is for the successive high waters two feet, and for the low waters three feet six inches.

5. The average variation from twelve hours, in the interval between two successive high waters, is three-quarters of an hour, and between two successive low waters, half an hour. The average variations of the same intervals when the moon is furthest from the Equator, are, respectively, one hour, and three-quarters of an hour.

6. When the moon's declination is North, the higher of the two high tides of the twenty-four hours is the one which occurs about eleven and a half hours after the moon crosses the meridian; and when the moon's declination is South, the one which occurs about one and a half hours after the moon's meridian passage.

6. Bis. Or, the following rule may be used, which applies when the moon crosses the meridian between midnight and 11 A. M., or between noon and 11 P. M.

If the moon is South of the Equator and passes the meridian in the morning, the high water will be higher than the afternoon high water; if it passes the meridian in the afternoon, the afternoon high water will be the higher. If the moon is North of the Equator, and passes the meridian in the morning, the afternoon high water will be the higher.

7. The lower of the two successive low waters of the twenty-four hours, occurs about seven hours after the higher of the two high waters.

8. The average difference between the hight of the higher high water and of the lower low water, is five feet eleven and a half inches, and the greatest difference is seven feet ten inches.

The above rules were drawn up so as to avoid technical terms.

IV.—METEOROLOGICAL OBSERVATIONS,

MADE AT SAN FRANCISCO, FROM JANUARY, 1851, TO JANUARY, 1858. [By Henry Gibbons, M. D.]

Most of the subjoined tables explain themselves sufficiently. Those relating to rain being of the greatest interest and importance to California, are given in detail. Table 6 shows every rain that has fallen since 1850. December appears to have been the most rainy month, but there is one day, the 8th of December, on which no rain fell in the entire period of seven years. A marked abatement of rain is observable from about the middle of January to the middle of February. One-third of the average yearly rain falls before the first of January, one-third in January and February, and the remaining third subsequent to the first of March. March and April supply nearly as much rain as any other two months. In 1853, there was nearly five inches in April, and in 1855 upwards of five and a half inches. In the latter year more than two inches fell in May.

1.

TABLE OF MEAN TEMPERATURE,

Showing the Mean Temperature of each Month at Sunrise and at Noon, and the Mean of the extremes for each Month, from 1851 to 1857, inclusive; also, the Mean Temperature for each Year.

Sunrise.

Noon.

Mean of Extremes.

1851 1852 1853 1854|1855) 1856 1857 1851 1852 1853 1854 1855 1856 1857 1851 1852 1853 1854 1555 1856 1857 J41 7 44 647 642 344 7 43 4 45 756 9 57 0 56 564 257 354 156 749 350 852 0 48 251 0 48 8 51.2 F42 0 45 7 48 247 950 347 346 1 60 0 60 4 60 159 263 360 1 56 661 053 154 153 6 56 8 53 751 4 M44 045 2 49 6 47 251 8 47 9 49 163 7 60 7 62 161 067 063 962 7 53 8 52 955 954 1 59 4 55 9 55 9 A48 2 45 451 751 150 648 7 51 4 673 65 464 8 68 464 963 1 66 157 755 458 359 857 7 55 958 8 M 49 6 47 8 53 4 49 0 50 1 49 350 5 64 3 62 3 68 0 64 664 463 3 64 657 0 55 1 60 756 8 57 7 56 357 5 J50 951 9 52 7 50 1 52 0 50 953 4 66 7 68 971 166 867 9 67 368 558 860 461 958 459 959 1 61 0 J51 5 53 152 551·954·952 052 6 64 3 69 7 68 1 70 6 67 566 865 7 57 9 61 460 361 361 2 59 4 59 2 A 55 0 53 6 52 9 52 4 55 3 52 9 52 5 69 4 68 7 67 0,68 3 69 666 3 65 662 261 260 060 4 62 5 59 6 59 1 S54 052 9 55 1 53 355 0 53 952 5.69 373 470 267 769 969 169 061 663 162 760 562 461 5 60 7 053 450 054 653 354 8 50 1 52 6 70 4 67 470 9 68 1 68 365 1 68 7 61 958 7 62 760 7 61 6 57 6 60 6 N53 449 850 95) 746 6 47 4 46 663 6 61 363 0 65 1 59 259 3 62 556 355 557 057 9 52 9 53 3 54 5 D46 146 246 7 47 0 43 3 42 0 42 9 56 6 55 457 460 752 252 056 251 350 8 52 153 847 8 47 0,49 5 M48 848 951 349 750 849 350.564 4 64 264 9 64 664 462 663 6 56 656 5 58 157 157 6 56 0 57'0

2. TABLE OF CLOUD AND MIST FOR 1857,

Showing the proportionate Time in each Month when the Sky was Clear and Cloudy, given in Days; the number of Days when the Sky was Clear, from Sunrise to Sunset, and the number Cloudy; the number of Days on which Rain fell, and the number of Days on which there was more or less Mist.

[merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small]

3. TABLE OF WINDS FOR 1857.

The direction of the Wind is noted three times a Day, so that three Observations in the Table are equal to one Day. The proportion of Land Winds and Sea Winds is given in Days, the Land Winds being from N. W. to E., and the Sea Winds from S. E. to W. The number of Days when the Wind was high is given in the last Column.

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors]

4. TABLE OF EXTREMES OF HEAT AND COLD, Showing the greatest degree of Heat and the greatest degree of Cold in each Month, from December, 1850, to July, 1858.

1850.

1851.

1852.

1853.

1854.

1855.

1856.

1857.

1858. Mos. Max Min. Max Min. Max Min. Max Min. Max Min. Max Min. Max Min. Max Min. Max Min.

Jan

Feb

Mar

Apr May Jun July Aug Sept

Oct.

Nov

Dec.

69 25 72 33 60 33 67 32 62 29
69 38 72 41 70 40 68 31 70 29
72 38 78 44 80 41 74 41 73 34
83 45 78 40 69 40 73 40 80 38
73 43 83 44 69 43 75 43 87 40
74 47 82 49 74 46 87 50 77 44
87 46 90 51 78 48 72 50 86 48
85 50 79 53 80 49 83 50
87 46 84 50 85 51 93 50
83 46 79 51 79 41 83 45

64 30 64 35 62 41
71 33 65 40 67 42
74 34 81 36 77 41
84 42 82 37 75 46
71 45 67 41 81 47
78 49 80 49 87 50
73 47 79 49 78 51
82 50 76 49 76 51
75 50 98 45 88 50
83 47 78 46 85 49
73 41 80 40 73 44 72 47 67 42 74 40 72 31
64 28 61 35 63 36 69 40 71 38 61 29 58 35 60 34

84 30 98 35 88 40 87 25 90 29 85 33 93 31

From the foregoing table it appears that the greatest degree of cold at San Francisco, in seven years, was twenty-five degrees, or seven below the freezing point. This may be set down as nearly the extreme cold ever felt here. In three of the years the mercury did not fall to the freezing point. In 1853 the lowest point was eight degrees above freezing.

The extreme of heat was ninety-eight degrees-a very unusual temperature for San Francisco, though much below the greatest heat in the interior. In 1856 the highest temperature was eighty-five, and in 1851 the thermometer did not rise above eighty-four.

5. TABLE OF COMPARATIVE RAINS,

Showing the amount of Rain fallen at stated times, in every Rainy Season from 1850 to 1858; four stated Periods in each Month being given.

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][ocr errors][merged small][merged small][merged small][ocr errors][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small]

66 14

10 45

[ocr errors][merged small][ocr errors][merged small][merged small]

66

.28

March.7 ..15

..23

April .7

แ ..31

..15

"..23 "..30

66

May .7 6.32 18.68 32.37 21.94 22.13
..15
6.32 18.68 32.65 21.94 23.87 19.87 20 20 21 47

3.05 12 02 21.59
14 69
3 20 12 04 21.59 11.48
15.09 14:55
3.30 12.09 22.75 15:46 12.23 15.09 17.89 14.27 14 15
3.30 16.79 22.75 15.66 13.81 15 09 18 44 14.27 15.01
3.30 17.95 23 71 18.43 14 24 16.04 18.60 14.79 15.88
4.05 17.95 23.71 18.56 14 24 16.04 18.94 15 10 16 07
5.18 18.49 27.56 18.63 16.54 16.93 20 16 19.92 17.93
5.67 18.49 27.56 18.63 16.61 16.99 20 16 21.33 18 18
6.12 18.49 28.68 18.92 21.67 19.22 20.16 21 47 19 34
6.32 18 64 32 19 19.62 22.07
6.32 18.68 32.34 21.94 22 13

8 19
8 19

11 68

12.82

11.81

14 27

12.56

[ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small]

..23 7.01 18.98 32.65 21.94 24.27 20.63 20.20 21.81 แ ..31

20.94 7.01 18.98 32.69 21.94 24.27 20.71 20 22 21.81 20.95

1857 To'l

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][ocr errors][merged small][merged small][ocr errors][ocr errors][merged small][merged small]

6. TABLE OF DAILY RAINS, Showing the Date and Amount of every Rain from Summer of 1850 to Summer of 1858. 1854 1855 1856

Date 1850 1851 1852 1853

Sept.7

10

1.00

08

Date. 1850 1851 1852 1853 1854 1855 1856 1857 To'l

1.00 Oct 24

[blocks in formation]
[blocks in formation]

06 Nov.3

16

20

20

20

8

11119

1*50

12

33

[blocks in formation]
[blocks in formation]
« 上一頁繼續 »