METEOROLOGY. 



' THE CUMATE OF SACRAMENTO, CALIFORNIA, BY THOMAS M. LOGAN, M. D. 

 Latitude SS'i 3i' 41" N, Longitude 12 1° 27' 44" W. 



As supplementary to the abstract of meteorological observations for 

 il8o3, 1854, and 1855, published in the reports of the Smithsonian 

 Institution, the accompanying tables for 1856-'57, together with the 

 results of the aggregate five years, have been prepared. 



It may not meet the exactions of a rigid science to deduce a positive 

 view of the climate from a series of observations extending through 

 only five years, still an approximation may now be arrived at that 

 "will be sufficiently near to afford a very just appreciation of some of 

 the climatic features of this portion of the great valley of the Sacra- 

 mento, due allowance being made for irregularities and disturbing 

 causes. Owing chiefly to the difficulty of procuring reliable instru- 

 ments and proper tables and instructions, the records, which were 

 made in various forms and with differing calculations, required re- 

 arrangement and tabulation to render them comparable with each 

 other. These considerations will be a sufficient apology with those 

 who have much experience in arranging statistical tables for a certain 

 amount of inaccuracy which has crept into our former publications. 

 In the present instance we have used every possible precaution while 

 rectifying former errors,* which are herewith specified, that the advan- 

 tages already received may be rendered more valuable hereafter. 



BAROMETER. 



The series of barometric observations have not been, in one respect, 

 continuous. Had they been conducted with one and the same instru- 

 ment doubtless some valuable deductions might have been gathered 

 from their analysis ; as it is we can only note some of the most obvious 

 ■ results. During 1853 the'ordinary ship barometer, (the only one to 

 be had then,) which was used, appears to have ranged entirely too 

 |low. The readings from this instrument, as well as those which were 

 registered from a common open cistern, and a siphon of Gay Lussac, 



• Errata in former ptiblications. — The latitude and longitude of Sacramento are correctly 



given above, and are erroneous in the previous reports. 



1853.— Car. Mean for January, for 29.65 read 29.75 ; annual mean, for 30.01 read 30.02 



inches Therm. Mean maximum, for 800.40 read 800.04; mean minimum, for 49O.00 read 



490.08; mean for October, for 780.00 read 730.00. Winds. SE., total, for 101 read 111. 

 . 1854.— Bor. Mean of January, for 29.11 read 30.11; minimum of May, for 29.00 read 

 f!29.60; mean minimum, for 29.76 read 29.81; annual mean, for 29.98 read 30.07 inches. 

 ' Therm. Mean maximum, for 790.54 read 790.29; mean minimum, for 420.72 read 42.73 



Rainy days. March, for 9 read 4. Inches of rain, for 8.25 read 3.25. Annual total of clear 



days, for 223 read 228. Total rainy days, for 60 read 55. 

 ' 1855. — Bar. Maximum of July, for 29.85 read 30.15; mean maximum, for 30.09 read 30.14 



inches. Dew point. Annual mean, for 470. 52 read 460. 69. 



