1-18 Mr William Sturgeon un the Autoiu Burecdis. 



which presented phenomena of very rare occurrence, a description of 

 them, as they appeared at this place, can hardly fail to be interest- 

 ing to philosophical inquirers, more especially as data are still want- 

 ing to establish a foundation for a true theory of the meteoi-, a phy- 

 sical problem of long standing, and, hitherto, without any satisfactory 

 solution. 



The first grand display of the aurora horealis, in this list, occurred 

 on Wednesday evening, 18th October 1848. It began with the 

 close of the day, and lasted, with various degrees of brilliancy, till 

 ten o'clock, or probably later ; for, labouring under the effects of a 

 severe cold, I could not watch it closely out of doors. It consisted 

 of an extensive arch of light, wliich crossed the magnetic meridian 

 at nearly right angles (which, liowever, was not its invariable posi- 

 tion, but tliat which it assumed during the greater part of the dis- 

 play), and immense floods of lambent streamers, which occasionally 

 flowed gently upwards and downwards, from various parts of the arch. 

 The avera'^fe colour of the light was that of a candle-flame, though 

 in some parts, and especially towards the eastern extremity, the 

 colour was red, inclining to violet. I observed nothing extraordinary 

 in these streamers, nor in the general aspect of the aurora; but for 

 reasons already stated I could not make a minute survey. 



For several days previous to this aurora, the atmosphere had been 

 highly charged with the electric fluid. On the preceding Saturday, I 

 had the electrical kite elevated about 400 yards, from the string of 

 which a small jar was rapidly and frequently charged ; a steel needle 

 was magnetized, and its poles reversed several times, by the dis- 

 charge of the jar, and also by sparks direct from the kite-string. The 

 magnetic polarity of the needle indicated a downward current in the 

 string, which was the case in other experiments on several days pre- 

 viously, though not to the same extent of power. 



This auroi-a was obseivtd at many places wide apart, which shewed 

 that it occupied an immense space in the heavens. It has been dif- 

 ferently described by different observers, to whom it appears to have 

 presented different aspects. The brief description given above, is 

 copied from my journal, the particulars being written down on slips 

 of paper as the phenomena occurred, and afterwards copied into the 

 journal, which is my usual mode; for it is next to impossible to re- 

 member all the varied features which the meteor presents during the 

 several hours that is sometimes required to watch its manifold and 

 rapid transformations. 



The next display of the aurora borealis, of any consequence, oc- 

 curred 27th October. During the morning and all the forenoon we 

 had continuous rain, which cleared oft' about two p.m. I had been 

 looking out for the aurora all the evening, and about six o'clock an 

 arch of dim light appeared in the northern heavens. It was very 

 low, and not of that extensive horizontal span occupied by the aui'ora 

 of the 18th instant. The western extremity reached a little west- 



