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OBSERVATIONS ON THE AURORA BOREALIS.

discharge of the jar, and also by sparks direct from the kite string. The magneticpolarity of the needle indicated a downward current in the string, which was thecase in other experiments on several days previously, though not to the same extentof power.

This Aurora was observed at many places wide apart, which showed that it occu-pied an immense space in the heavens. It has been differently described by differentobservers, to whom it appears to have presented different aspects. The brief descrip-tion given above is copied from my journal, the particulars being written down onslips of paper as the phenomena occurred, and afterwards copied into the journal,which is my usual mode; for it is next to impossible to remember all the varied fea-tures which the meteor presents during the several hours that is sometimes requiredto watch its manifold and rapid transformations.

The next display of the Aurora Borealis, of any consequence, occurred Oct. 27th.During the morning and all the forenoon, we had continuous rain, which cleared offabout two p.m. I had been looking out for the Aurora all the evening, and aboutsix 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 Aurora of the 18th instant.The western extremity reached a little westward of Arcturus , the star being muchhigher than the auroral arch; but, as it was fast descending towards the horizon, itpassed through the arch; whilst the latter remained stationary, or nearly so. Somefine groups of lambent streamers occasionally flowed upwards from different parts ofthe glowing bow; and also another feature which the Aurora displays—the gentleblushes of pale soft light were frequently seen in the dim haze that almost invariablyaccompanies the Aurora Borealis. Between seven and eight o’clock, a few stragglingclouds came floating across the Aurora. Such interruptions to the observer’s vieware exceedingly interesting events ; for they never fail to show that the auroral lightis at a greater distance from the place of observation than the clouds themselves, whichis one step, at least, gained towards obtaining a true true theory of the cause of themeteor; but should nothing further be ascertained, by the interposition of theseclouds, than the locality or region of the atmosphere in which the Aurora is situated,it would be the means of setting at rest an inquiry of great interest concerning thereal height of the meteor.

There are other features occasionally conspicuous in the Aurora Borealis, whichhave long been noticed and recorded as the most astonishing appearances of thewhole. I allude to the colours that sometimes adorn the meteor. They have for along time appeared to me to arise from a decomposition of the true auroral light(white light, or rather that of a soft pale candle flame), accomplished by refractionsand reflections amongst the abundance of aqueous particles hanging in the regionsof air where the electric fluid is in motion, or between those regions and the eye of