120 Notes to the Extra Observations of Magnetometers, January 26 — February 1, 1845. 



NOTES ON THE AURORA BOREALES SEEN AT MAKERSTOUN. 



d. h. in. 



Jan. 26 13 10. Very thin cirri radiating in bands, as on the 24th, from NW by N. and SE by S., forming a very 

 irregular halo roimd the moon ; the cirri seem to spring in tufts from the border of the halo, in 

 the direction of the radiations, namely, from SE by S. 

 25. The halo rather better defined, although still irregular. The colours of the interior corona are also 

 more distinct. There may be auroral light to N., but if so, it is completely masked by the cirri 

 and moonlight. 



14 10. Cirri much as before, very like a bank of auroral light from NW by N., eastward. There is some- 



thing decidedly peculiar about these cirri. At 14^ 10™ observed towards SW., altitude 45°, a series 

 of parallel narrow bands of cirri, some nearly 30' broad ; watched them very attentively, in order 

 to see if any pulsations occurred ; could not see that they moved excepting longitudinally ; at 14™ 

 they had arrived at the moon and broken the halo into bands ; they had thus moved bodily about 

 40° in less than 4™. It is conceived that the length of the bands are increased as well as their 

 number. It is to be remarked, that these bands did not lie in the same direction as the otlier 

 cirrous streaks, the latter lie nearly in the magnetic meridian, the bands lie nearly east and west. 

 The bands from NW by N. span the sky in complete arches. Were the cirri not seen plainly 

 near the moon, and the connection traced to the N., the appearance on the N. horizon would be 

 noted unhesitatingly as the common homogeneous bank of auroral light. 



15 10. Halo gone at present, but ciiTous bands nearly as before. A black patch of cirro-stratus near the 



NW. horizon ; this was also noticed at \2>^. 15™. It has been noticed throughout, that the decli- 

 nation magnet moves irregularly, by fits or jerks, the vibration often ceasing, or nearly so, suddenly. 

 30™. W. portion of halo visible ; many patches of cirro-stratus or scud risen on NW., N. and 

 SW. horizon. 45™. A rather thicker cirrus coming up to the meridian, moving slowly, with 

 patches of cirro-stratus. The clouds continued moving up more quickly, becoming more and 

 more dense till 16*^ 10™, when the moon was totally obscured, though thin cirri were still seen to E. 

 Light seen through the clouds to N. 

 Auroral light seen through the clouds to N. 



As far as the aurora can be seen it appears to be quite amorphous ; no pulsations or streamers. 

 Auroral light to N. 30™. Auroral light becoming fainter. 

 There seems a faint auroral light among the haze to N., but it is doubtful. 



The magnets having exhibited some slight ii-regularities in their motions, the observer looked to see 

 if he could detect any appearance of aurora, the sky being perfectly clear, but he could not ; 

 having again entered the Observatory for a minute, he returned at 9™, and found the sky suddenly 

 (in a minute or so) turned milky, with the exception of a streak of blue, reaching fi'om SW. to- 

 wards NE., another streak meeting it near the zenith (from NE. X) at the same time it became much 

 lighter to N. and especially to NE. There was now without doubt aurora, with faint pulsations. 

 12 20. A most strange aurora; one portion extends in a bank along the horizon from SW. to NE. to an 

 altitude of 45° above WNW., another similar portion to E. ; pulsations all round, especially to 

 SE. ; just now streaks with the bluish sky to E., altitude 45°. 

 25. The western bank brightest on the whole ; there is a sort of radiation from SW. and NE. ; six-tenths 

 of the sky covered by aurora, and as much to S. as to N. : at times no pulsations visible, but the 

 aurora seems to extend like a thin haze over the deeper blue of the sky ; the general position of the 

 great boundaries are pretty permanent for some time. 

 36. Very bright pulsation ; meteor shot rapidly towards the zenith from 60° altitude above NE. ; streaks 

 to E. still bright ; patch to SSW. with pulsations ; all the stars distinctly visible through the 

 aurora. 

 45. Much as before ; the Pleiades are immediately out of the W. bank, as they have been throughout the 



whole time. 

 50. Sky nearly covered with the milky aurora ; bank of cirro-stratus during the whole period to 

 SE. ; no other clouds visible ; streaks of blue sky to NW ; dark space throughout the observa- 

 tions in N. horizon. The edge of the cirro-stratus in E. and S. horizon, seems to be rather brighter 

 than the rest, just like the clouds in the N. horizon during aurora. 

 The observer watched the appearance of this aurora till 13** 10™. In its general features it con- 

 tinued much as before ; a rather wide streak of sky to NW. noticed at 50™ (which, it is believed 

 existed before that minute), passing immediately below the Pleiades seems very permanent in its 

 form and relation to the bank of aurora. The W. bank was on the whole brightest, although very 

 variable in its brightness throughout. The luminosity of each mass was rather uniform, excepting 

 a patch to SSW. which was much brighter than the surrounding aurora. The dark space on the 

 N. horizon mentioned at 50™, was something like that under the usual auroral arch, but ill formed, 

 and not easily separated in some places from the aurora. 



Jan. 



28 



7 



35. 







8 



30. 

 50. 



Jan. 



29 



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5. 



Jan. 



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10. 



Feb. 



1 



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Mi 



