158 Meteorological Observations for December 1830. 



METEOROLOGICAL OBSERVATIONS FOR DECEMBER 1830. 



Gosport: Numerical Results Jbr the Month. 



Barom. Max. 30-45. Dec. 15. Wind W. Min. 28-86. Dec. 0. Wind S.E. 

 Range of the mercury 1-59. 



Mean barometrical pressure for the month 29-607 



Spaces described by the rising and falling of the mercury 8-130 



Greatest variation in 24 hours . Number of changes 22. 



Therm. Max. .r, >0 . Dec. 6. Wind S.E. Min. 16. Dec. 24. Wind N. 

 Range 36. Mean temp.of exter. air 38'26. For 29 days with in 41-53 

 Max. var. in 24 hours 20 0> 00. -Mean temp, of spring-water at 8 A.M. 51-58 



De Luc's Whalebone Hygrometer. 



Greatest humidity of the atmosphere, in the morning of the 29th ... 92 

 Greatest dryness of the atmosphere, in the afternoon of the 24th... 59 



Range of the index 33 



Mean at 2 P.M. 74-4. Mean at 8 A.M. 80-8. Mean at 8 P.M. 787 



of three observations each day at 8, 2, and 8 o'clock 78'0 



Evaporation for the month 0-80 inch. 



Rain in the pluviameter near the ground 2-430 inches. 



Prevailing wind, N.W. 



Summary of the Weather. 



A clear sky, 2; fine, with various modifications of clouds, 12 ; an over- 

 cast sky without rain, 10^ ; foggy, 1 ; rain, 5. Total 31 days. 



Clouds. 



Cirrus. Cirrocuinulus. Cirrostratus. Stratus. Cumulus. Cumulostr. Nimbus. 

 16 4 31 14 10 18 



Scale of the prevailing Winds. 



N. N.E. E. S.E. S. S.W. W. N.W. Days. 

 5J 5 3 3 li 2.i 3 6 31 



General Observations. This month has been generally wet and windy, 

 and cold from the 10th to the 28th. In the night of the 5th a hard gale 

 blew here from the South-east with rain, and there was a considerable de- 

 pression of the mercury in the barometer. At Plymouth serious damage 

 was done among the shipping, and many lives were lost during the gale 

 from the same quarter : many merchant brigs were driven on shore, broken 

 to pieces, and their cargos destroyed. 



Early in the morning of the 17th an inch in depth of snow fell here, 

 which disappeared by the evening: there were also sprinklings of snow on 

 the following morning. 



On the 21st the maximum temperature occurred in the night, and was 

 followed by a little rain and wind from the South-west. In the afternoons 

 of the 23rd and 24th it again snowed. The icy efflorescences which accu- 

 mulated pretty thick on the inside of the windows in the night of the 23rd, 

 did not dissolve during the following day, even in rooms with fire. A 

 Fahrenheit's thermometer placed on the ground in the night of the 24th, 

 receded to fourteen degrees, and to sixteen degrees in the nights of the 

 23rd and 25th. There was a difference of twenty-five degrees in the maxi- 

 mum temperatures of the 22nd and 24th ! which was certainly a very great 

 change in forty-eight hours. About this time a heavy fall of snow took 

 place at Limerick in Ireland, which was succeeded by hard frost. In the 

 night of the 26th half an inch in depth of snow fell. 



The mean temperature of the external air this year (1830) is a quarter 

 of a degree lower than that of the coldest year since 1816, 



The 



