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.

Jos.

1851 1852 1853 1854 1855 1856 1857 1851 1852 1853 1854 1855 1856 1857 1851 1852 1853 1854 1555 1856 1857

J41 7 44 6 47 642-344 7 43 4 15 7 56 9 57 0 56 5 64 2 57 3 54 1 56 7 49 350 8 52 0 48 251 0 48 8 51.2 F42 0 45 7 48 247 9 50 347 346 1 60 050 460 159 263 3 60 156 661 0 53 154 153 6 56 8 53 7 51 4 M44 0 45 2 49 6 47 251 8 47 9 49 1 63 7 60 7 62 161 067 063 962 753 8 52 955 954 1 59 4 55 9 55 9. A 48 2 45 451 751 150 648 7 51 4 67 3 55 4 64 8 68 464 963 1 66 1 577 55 4 58 359 8 577 55 958 8 M 49 6 47 853 4 49 0 50 1 49 350 564 362 368 0,64 664 463 3 64 657 055 160 7 56 8 57 7 56 3 57 5 J50 9 51 952 750 152 0 50 9 53 4 66 7 68 971 166 867 967 368 5 58 860 461 958 459 959 1 61 0 J51 5 53 152 551-954-952 052 6 64 3 69 768 1 70 6 67 566 8 65 7 57 961 460 361 361 2 59 459 2 A 55 053 6 52 952 455 3 52 9 52 5 69 468 767 0 68 369 666 3 65 662 261 260 0 60 4 62 559 659·1 S54 052 955 153 355 0 53 9 52 569 373 470 2 677 69 9 69 169 061 663 1 62 7 60 562 461 5,60*7 053 450 054 653 354 850 152 6 70 4 674 70 9 68 1 68 365 1 68 7 61 9 58 7 62 760 761 6 57 6 60 6 N 53 449 850 95) 746 6 47 4 46 6 63 6 61 3 63 0 65 159 259 3 62 556 355 557 057 952 9 53 3 54 5 D46 146 246 747 0 43 342 0 42 9 56 655 4 57 4 60 7 52 2 52 056 251 350 852 153 847 847 0 49 5 M48 848 951 349 750 8 49 350.5 64 4 64·264 9 64 664 462 663 6 56 6 56 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.

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.

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.

Jun

July

78 49 80 49 87 50 74 47 82 49
73 47 79 49 78 51 87 46 90 51 78 48 72 50 86 48

74 46 87 50 77 44

Aug

82 50 76 49 76 51 85 50 79 53

80 49 83 50

Sept

75 50 98 45 88 50 87 46

84 50

85 51 93 50

Oct.

83 47 78 46 85 49 83 46

79 51

79 41 83 45

Nov
Dec.

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.

แ

..30 May..7

66

21.94 22 13

..23

แ ..31

6.32 18.68 32 34 6.32 18.68 32.37 21.94 22 13 15 6.32 18.68 32.65 21.94 23.87 7.01 18.98 32.65 21.94 24-27 20.63 20.20 21.81 20.94 7.01 18.98 32.69 21.94 24-27 20.71 20 22 21 81 20.95

19 87

20 16

21 47 20 61

19 87

20 16

21 47 20 62

19.87 20 20

21 47

20 87

6. TABLE OF DAILY RAINS,

Showing the Date and Amount of every Rain from Summer of 1850 to Summer of 1858.

TOTALS.-In 1851, 7·11 in; '52, 17·98; '53, 33·12; '54, 22′04; '55, 24-02; '56, 21-73; '57, 18'00; '58, 19-05.

Showing the Amount of Rain, in inches, in each Month, from the Autumn of 1850 to the Summer of 1858; also, the mean quantity for each Month of the Year in that period.

1850.

1851. 1852. 1853. 1854. 1855. 1856. 1857. 1858. Mean.

Months.

January

February.

March

65 58 4.11 4.27 4.52 8.44 207 4.36 3.63 35 12 1.16 8.41 4.64 43 8.66 1.32 3.14 1.88 6.40 4.81 3.17 4.31 1.64 1.56 3.94 3.46

V.-CONTRIBUTIONS TO THE CLIMATOLOGY OF CALIFORNIA.

BASED UPON FIVE YEARS' METEOROLOGICAL OBSERVATIONS AT SACRAMENTO.

[By Thos. M. Logan, M. D.]

THE physical features of California present every diversity of character, and this difference of conformation is a powerful cause of the variety of climate met with within its area. As a whole we cannot speak intelligibly of its climate, as we do of that of Cuba, or of our Southern, Middle, or the New England States, for it has many climates, anomalously distributed in abrupt contrast, and setting at naught our accepted notions of the effects of latitude and altitude.

In no other portion of the globe, therefore, are the requisite facts and statistics of meteorology more absolutely necessary than here for a correct understanding of the climatology. When the measures of heat, rain, wind and other conditions necessary to make up our knowledge of what is understood by the word "climate," are determined in a sufficient number of stations, we may then, by a comparison of these facts, and from the relation they bear to each other, reach inductively the processes by which the combinations and varieties are formed. As subservient to this end, the accompanying results of observations made at Sacramento have been prepared. The statistics of greatest value in climatology are the monthly summaries of the measurements of the conditions just referred to, giving the averages, or the fixed quantities, and these we have compressed into the smallest possible compass, in tabular form, purposing, when treating on any special subject to which they appertain, to comment thereon textually.

The results are most of them calculated from five years' observations made in accordance with the uniform system adopted by the Smithsonian Institution, at 7 A. M., 2 P. M., and 9 P. M.; and although the period is too short to meet the rigid exactions of meteorological science, in deducing positive conclusions, still an approximation may be arrived at that will be sufficiently near to afford a very just appreciation of the climatic features of that great valley, which constitutes, what may be topographically considered, the middle portion of California, and of which the city of Sacramento is the center.