612 



APPENDIX. 



[No. III. 



At 1 Oh. 45', bright moonlight. The sky, which had previously been very 

 clear, was suddenly overspread by a thin stratum of fleecy clouds. They 

 were in general orbicular, but were much crowded, so as to leave small 

 interstices of clear blue sky. A few stars were visible through the rarer 

 parts. About 7° or 8° above the northern horizon, there existed a mass of 

 cloud rather more dense, which began, soon after its formation, to emit a faint 

 yellowish light. In two minutes the light became brighter, and spread towards 

 the S.W., by a slow waving motion, like an increasing volume of smoke, 

 rolling parallel to the horizon. It continued sweeping round the sky in this 

 manner, until the produced end bore N.W., and then became irregularly 

 elevated in the middle, assuming an arched form. At the instant at which this 

 elevation took place, a stream of light issuing from the S.W. formed an arch 

 about 2° higher than the other, and parallel to it. The second arch exhibited 

 nearly the colours of the rainbow. 

 The red colour occupied its under edge, and it darted down towards the inferior 



J * 



arch a number of light-red fringe-like processes. The two arches were scarcely 

 formed when they disappeared, but instantly appeared again, and continued to 

 do so in rapid succession for a minute or two, the upper one retaining its 

 prismatic tints, and the under one an uniform pale yellow colour. The motion 

 of the light by which the arches were re-produced, was sometimes from right 

 to left, sometimes in the opposite direction. The upper arch too was occa- 

 sionally split into narrow parallel streams, which had not only a rapid lateral 

 motion in the direction of the arch, but were also lengthened out, both upwards 

 and downwards, by sudden flashes. At such moments the coloured tints were 

 most vivid ; the red always predominating. 



About five minutes after the first appearance of the Aurora, a bright mass 

 of light was observed bearing N.N.W. ; from which a column, possessing 

 prismatic tints, shot up as high as the zenith, a similar column at the same 

 time springing to meet it, from the site of the two arches which had now 

 disappeared. A brilliant arch was thus formed, whose extremities bore 

 W.N.W. and S.S.E. In an instant thereafter, the whole sky was covered with 

 small arcs, and irregular masses of light, mostly composed of short parallel 

 beams. These masses moved rapidly from the horizon towards the zenith, 

 and back again. The duration of this phenomenon was about seven or eight 

 minutes,, when the light wholly disappeared. . 



