164 TRANSACTIONS OF THE 



METEOROLOGICAL REPORT. 



BY THOMAS JI. LOGAN, M. D. 



METEOROLOGIST TO THE BOARD OF AGRICULTURE, 



In order to aflFord the agriculturist, as far as practicable, a succint and 

 accurate idea of the prominent features of the climate of California, the 

 accompanying tables have been prepared. Through this means, in keep- 

 ing with the spirit of the age, rather than by tedious comnientjuy, -vve 

 are the better enabled to demonstrate, at a glance, intensities, amounts, 

 and results, with an infinite saving of time, and whnt is fur more desira- 

 ble, with numerical precision and truth. Meteorology is a very young 

 science — far from being regarded in the light of an exact one — and until 

 observations for a long series of years shall have been made at many 

 stations, we will not be in possession of trustworthy facts on which to 

 ground absolutely correct reasoning about the weather and its changes. 

 Nevertheless, although we cannot, like the astronomer, who deduces the 

 laws under which the celestial bodies move, and ap])lies them with uner-. 

 ring certitude to the prophesying of future events, foretell the everchang- 

 ing phase of the atmosphere, or prepare an almanac like "Old Moore's," 

 to show what weather is to be expected at any given date, still we may, 

 even now, with the data in hand, obtain a clue to the climate of the 

 region we inhabit, which, we trust, will become more and more available 

 with the increasing experience of every added year. 



Tl>e tabulated series of thermometi-ic monthly means, with the varia- 

 tions therefrom, at the hours of the three daily observations, give, with 

 their graphic representative, the range of the temperature during the 

 Seasons of the 3'ear, and when viewed connectedly, show the difference 

 of the climate of the places whence they are derived. They also show 

 the variations of the hours of the day. As observations two p. M., give 

 nearly the greatest temperature, at that time, dui'ing the month, and as 

 the mean of the seven A. M., two P. M., and nine v. M. observations gives 

 nearly the mean of the month, so when it is shown that the mean, at two 

 p. M., in a month, or scries of months, is -}-5° 7'. it expres.ses the fact 

 that the thermometer during twenty-four houi's has a range of 5° 7', 

 above and below the mean. Many other facts of value may be gathered 

 from these tables, by tho.sc familiar with meteorological studies. 



In the comparative tal)le, the results of the annual averages of tem- 

 perature for the whole period observed, together with the range derived 



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