304 METEOKOLOGY. 



the 26tli the temperature of the earth at 53 feet below the surface 

 (the depth then obtained in an artesian well) was 60°, the thermometer 

 having fallen about a degree and a half for every 10 feet from the 

 depth of 15 feet, at the time of reaching which latter depth it read 66°. 



September. — This month was characterized by variable weather. 

 The barn swallow made its last appearance on the 5th. On the 10th, 

 at 5^ o'clock p. m., we were suddenly visited with a high wind fromi 

 a heavy bank of clouds in the southwest horizon, which at one time 

 presented indications of approaching rain, but was intercepted by the 

 arid mountains and high lands of Santa Cruz, Alameda, and Sam 

 Francisco, where the accompanying lightning and thunder are reported' 

 to have been extremely violent. 



For several days previous to the equinox a regular declension of 

 atmospheric pressure was experienced, attended with a stagnant, 

 sultry condition of the air. This was succeeded by a sprinkle of rain 

 (the first of the season in this locality) at daylight on the 20th, when 

 the lowest reading of the barometer, as above, was recorded. As the 

 sun entered Libra, however, the weatlier presented one of the most i 

 favorable specimens of our autumnal climate, a fresh circulation of' 

 air being kept up by southerly breezes. 



The most remarkable feature of the month was the brilliant ?erolite( 

 which appeared on the evening of the 11th, at about 8 o'clock. As ■ 

 it was seen simultaneously in an area of several hundred miles, 

 bounded by Red Bluffs, Iowa Hill, Stockton, San Francisco, and i 

 Santa Cruz, the probabilities are that at the time of its brief appear- 

 ance it was in the upper regions of our atmosphere, and that, judging [ 

 from the interval that elapsed between its explosion and the reaching 

 of the report here, which resembled distant thunder, its distance then 

 was between thirty and thirty-five miles. After comparing all the 

 different accounts that have reached us, it would seem that its course 

 was on the southern side of the zenith, from SE. to NW., and that 

 its relative position to the point of aspect here was at first about forty 

 degrees above the horizon, and twenty when it vanished. When first 

 seen it appeared but little larger than Venus, but as it approached i 

 the earth it increased in size as suddenly as it diminished again just t 

 before bursting into brilliant corruscations of light that reflected all I 

 the prismatic colors. The moon was near the close of ils second I 

 quarter at the time, and the atmosphere clear and transparent. 



The Sacramento river fell to a lower point than has ever been before ; 

 observed, which will be the zero of the scale of a new river gauge 

 about to be constructed by the city. Its present mean temperature 

 twelve feet below the surface reads 70°, while that of well water at 

 the same depth is 60°. The temperature in the artesian well at 

 sixty-five feet below the surface is 59^^°. 



October. — The mean temperature of this month was 5°. 47 minus 

 the average. On the 1st the flight of wild geese southwardly, which i 

 had been observed since the 8th September, prepared us to expect the 

 rain that fell on five different days — the 7th, 15th, 17th, 19th, and 

 24th ; and though not amounting to much in quantity, it was sufficient 

 to indicate that the atmospherical changes which characterize the 

 rainy season had set in. The first frost occurred on the 20th, and ice 



