260 On the Aurora Borcalis. 



Several of the Auroras affected the electrometer and the mag- 

 netic needle, causing in the former marked and increased diver- 

 gence of the gold leaves, and considerable oscillation and varia- 

 tion in the movements of the latter. I will copy from my 

 journal the notice of one Auroral exhibition: — "Dec. 17th, 

 1857, at 6*30 p.m., observed a faint Aurora from S.S.E. to B ; 

 nothing particular in its appearance, it died out about 7*15. 

 At 10 p.m. observed a bright Aurora extending from S. to 

 N.N.E. ; a low bank of fog, 5° above the horizon, formed the 

 edge of an arc about 1° broad ; 2° above this another arc 

 was situated, about 4° broad ; these changed into broad lumin- 

 ous clouds at times, and then again formed one thin long arc, 

 extending continuously from S. to N.N.E., with streamers 

 ascending 8° to 10° towards the zenith; the colour generally 

 a yellowish-green, but once it was quite reddish in the E., at 

 which point the Aurora was most intense and constant. I 

 again noticed the pulse wave; it oscillated from S.S.E. to E. ; 

 the ' merry dancers ; sometimes was the form assumed ; once 

 or twice there was an instantaneous intensity in the light of the 

 whole mass, and as quick a relapse to the original. 



" In the thick body of the Aurora the light was so intense as 

 completely to hide the appearance of stars of the first magni- 

 tude, — through the streamers the stars showing, although but 

 dimly. At 11 o'clock, I noticed a shooting star of a very bright 

 character; it descended from 85° degrees above the horizon, 

 and below Saturn towards the horizon, but on approaching the 

 Aurora it was dimmed and then completely obscured; it fell 

 very slowly, when it came to the thick band it left a tail 2° be- 

 hind it. No sounds were heard with the Aurora ; those bands 

 which did appear were as luminous as those of last night, but 

 were more confined to one part of the sky. 12 p.m. : still con- 

 tinues, more concentrated and a little brighter ; dense streamers 

 longer and altogether higher above the horizon. Since the 

 appearance of the Aurora, the wind has increased. Tempera- 

 ture — 21°. 4 a.m. : the Aurora still brilliant and in the same 

 direction, forming more of an aeriform shape, and changing 

 sometimes to a reddish hue. 9 a.m.: still apparent, now crosses 

 the zenith, not in streamers but in shapeless patches of thin 

 light, from S.W. across the zenith to W. and W.S.W. ; also 

 from E. to N.W. a broad band, about 70° above the horizon in 

 E., is very persistent against the blue background ; the stars 

 are visible through it. Minute spicules of snow visible through 

 the atmosphere. As the daylight increased the Aurora became 

 less visible, and at 10 a.m. it was not seen, but in its place thin 

 fleecy clouds appeared, just as if it had been the cloud which 

 had been rendered luminous. At 10 30 a.m., whilst the cloud 

 still remained, I connected an electrometer with the copper 



