54 



NOTES ON THE AURORA AtlSTRALIS OF THE Htu JUNE, 18M. 

 By F. Abuott, F.ll.A.S. 



At 8 hours p.m., .1 distinguished foaturo of a rich and nire Aurora appeared, 

 commencing in <^he horizon about 20" E.S,E., forming an angle of about 20° to 

 the equator, at which point it took a path bordering on the ecpuitor nearly due 

 east and west. At 8 hours 20 minutes it formed an inverted cone with the 

 apexap]>arently lh° wide, i)ointing to the horizon, and the base about y.;^" wide, 

 with an altitude of 60". At this period it became very peculiar in its external 

 properties ; forming a large column of a clear silvery lustre, destined to H})au 

 the heavens in one entire arch. Its progress in this form became steady and 

 regular, but slow, until it reached the meridian, when it commenced to 

 form another inverted cone, with the apex pointing due west. At about 8 

 hoiu's 40 minutes it became a most superb object, the brightness of its white 

 light was so excessive as to drown the Via Lactea, and its form a double cone, 

 each cone with a slight curve — best described as resembling the form 

 of the Diatom Gyrosiyma domjatum tinder the microscope, the Aurora having 

 a dark line, as in the Navicula, running along its centre, in diameter about 

 5*:!:. At 8h. 45m. the Aurora band reached from a Capricornus to a Leo, 

 passing over a portion of Sagittarius, Scorpius, Libra, Virgo, and Jupiter to 

 Leo — the stars in each constellation being distinctly seen. 



On the apex of each cone reaching the two extreme points they both as of 

 one accord, began siinultaneousty and gradually to disappeai, and by a slow 

 process the cones, receded with a fluttering and rolling motion, an-iving at the 

 base nearly together. At about 8I1. 55m., the whole had vanished from sight. 



On the same evening, and during the time of the above phenomenon, a 

 very strong Aurora, or Southern light, illuminated the horizon for a space of 

 20°, on each side of the Pole, but it was quite distinct from, and had no 

 apparent connection with, the very peculiar and interesting band that formed 

 a path along the Zodiac. 



The meteorological state of the atmosphere at the time was humid. Rain 

 fell on seven out of the first eight days in June, but the sky was clear and 

 almost cloudless during the Aurora. 



Atmospheric pressure 29*681. 



Temperature 45°. 



Private observatory, 

 Hobart Town, 

 13th June 1864. 



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