344 Observations on the Aurora Borealis. 



Thirty-nine observations, on luminous appearances, rather 

 faint, were followed with rain in about thirty-six hours; wind, 

 generally s., very brisk. 



Forty-two manifestations, more vivid than the preceding, 

 with very brisk winds, principally s. w., and moderate rain 

 in about thirty hours. 



Sixteen still more vivid appearances, attended with corus- 

 cations and agitated motions, were succeeded with strong: 

 westerly winds, and rain in thirty hours. 



The average continuance of rain, succeeding the above 

 ninety-seven observations, was about eight hours. 



Twenty-four very vivid and brilliant appearances were fol- 

 lowed by strong gales of wind from s. w. in about twenty-six 

 hours, but no rain : the atmosphere mostly cloudy. 



Eleven exceedingly brilliant and beautifully coloured au- 

 rorae, with beautiful streams of variegated light, reaching up 

 to the zenith, were succeeded in about twenty-six hours with 

 very hard gales of wind, principally from the w,, accompa- 

 nied with very massy nimbose clouds, but no rain r these gales 

 continued about six hours in the above thirty-five observa- 

 tions. 



Twelve magnificent displays, with luminous arches, columns 

 of various colours darting sometimes to the zenith, and some- 

 times to the s. of the zenith, spreading themselves from N. e. 

 to N. w., attended by occasional flashes of lightning, meteors, 

 and shooting stars ; wind varying from s. w. to n. w., were 

 followed, in about twenty hours, with violent gusts of wind, 

 and heavy rains resembling thunder-showers; the average 

 continuance of the wind and rain being about four hours. 



Four still more magnificent displays than the preceding 

 twelve, attended with almost every variation of colour, mo- 

 tion, &c, were succeeded by very strong gales of wind; namely, 

 one from the w., a very hard gale ; two from s. w., still more 

 powerful, the wind being more by gusts ; and one from the 

 n. w., a perfect hurricane, tearing up trees, &c. These were 

 all succeeded on the following days by thunder, lightning, and 

 torrents of rain, for about four hours. 



Sixteen other manifestations, resembling the dawn of day, 

 the wind w. or n. w., were followed on succeeding days by 

 frosts. 



Twenty still more faint resemblances were not succeeded 

 by any apparent change of weather, which was generally mild 

 and calm. 



Hence it appears that the wet and changeable weather that 

 succeeds aurorae is, to the dry and unchangeable, as 164 to 20, 

 91* 8£ to 1 ; a ratio which must go far to prove that aurorae 



