158 Meteorological Observations for December 1829. 



AURORA BOREALTS. 



At six o'clock P.M. Dec. 14tli, a bright light appeared abrut 

 the magnetic north, and gradually formed into a small segment of 

 a circle, from the base of which in the horizon fourteen perpendi- 

 cular columns of light emanated to altitudes of from ten to twenty 

 degrees; their breadths varied from half to one and a half degree, 

 and they showed a faint red colour. At a quarter past six a well- 

 defined flame-coloured arc arose from the aurora, and was three 

 degrees in width; its vertex, when at its greatest height, was about 

 sixteen degrees in altitude, and its extremities terminated in the 

 N. by E. and N.W. by W. points of the horizon ; but it suddenly 

 disappeared, or was apparently extinguished by a dense passing 

 mist. When the mist had cleared awa}^, a distant mild light, which 

 often varied in height, remained about the magnetic north till nine 

 o'clock, or twenty minutes after the moon rose. A very heavy dew 

 fell during this meteoric appearance, and several small meteors oc- 

 casionally appeared over the aurora. 



METEOROLOGICAL OBSERVATIONS FOR DECEMBKR 1829. 

 Gosport. — Numerical Results for the Month, 



Barom. Max. 30-58. Dec. 31. WindN.E.—Min. 29-60 Dec. 18. Wind E. 

 Range of the mercury 0-98. 



Mean barometrical pressure for the month 30-117 



Spaces described by the rising and falling of the mercury 4-380 



Greatest variation in 24 hours 0-530. — Number of changes 21. 

 Therm. Max. 53° Dec. 5. Wind S.— Min. 18° Dec. 27. Wind N.E. 

 Range 35°.— Mean temp.of exter. air 36°-13. For 30 days with in f 3972 

 Max. var. in 24 hours 18°-00 — Mean temp, of spring-water at 8 A.M. 51-12 



De Luc's Whalebone Hygrometer. 



Greatest humidity of the atmosphere in the evening of the 21st ... 96° 

 Greatest dryness of the atmosphere in the afternoon of the 26th... 65 



Range of the index 31 



Mean at 2 P.M. 79°-3.— Mean at 8 A.M. 84°-l.— Mean at 8 P.M. 82-4 



of three observations each day at 8, 2, and 8 o'clock 81-9 



Evaporation for the month 0-80 inch. 



Rain in the pluviameter near the ground 1-20 inch. 



Prevailing wind, N.E. 



Summary of the Weather. 

 A clear sky, 2; fine, with various modifications of clouds, '9; an over- 

 cast sky without rain, 15; foggy, 1 ; rain, 4.— Total 31 days. 



Clouds. 



Cirrus. Cirrocuraulus. Cirrostratus. Stratus. Cumulus. Cuniulostr. Nimbm. 



10 5 30 2 2 13 13 



Scale of the prevailing Winds, 



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

 5 Hi 4i IJ 2i I 2 31 



(jeueial 



