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APPENDIX. 



[No. III. 



Aurora at this time were sluggish, but large masses of light were frequently 

 generated almost instantaneously. 



At 7h. 30', a number of arches sprung from the horizon in the N.W.b.N., 

 and sweeping across the sky in various directions suddenly curved in, to ter- 

 minate in the S.E. b. S. The arches were in general about 6° broad, and their 

 middles were distant enough from each other to spread on each side of the 

 zenith to the distance of 50°. 



From 9h. to midnight, the Aurora formed many arches of light, very various 

 in breadth and density, all having a common origin and termination in the 

 N.W. and S.E., but crossing the heavens in a variety of directions, so as to 

 occupy about three-fourths of the space on each side of the zenith. 



The middle portions of some of these arches ran horizontally across the sky, 

 whilst their extremities, making sudden curves, arrived at the common origin 

 and termination of all the arches, which were seated for the greater part of the 

 night about 4° above each horizon. At one time the light was arranged in a 

 series of curves, including each other, and having their convexities turned to- 

 wards the north on both sides of the zenith. In short, their arrangement was 

 continually varying, but the breadth of the arches at all times was greater in 

 the zenith. Large and diffuse columns of light sometimes shot up at right 

 angles from the convex side of the arches, and portions of broken arches were 

 occasionally seen in various parts of the sky, lying obliquely across the gene- 

 ral line of direction. The changes of form were not produced by a quick flash- 

 ing motion, but by the different parts of a new arch appearing simultaneously 

 but faintly, then gradually brightening up in a manner that could be traced only 

 by keeping the eye steadfastly fixed on a clear part of the sky, and watching 

 the evolution of the light there. 



At midnight a clear blue sky surrounded the zenith to the distance of about 

 20°, the rest of the sky had a light-grayish appearance, resembling the light of 

 the milky-way, many stars shining brightly at the time. In some spots this 

 diffuse light brightened up for a moment or two, assuming at the same time a 

 yellowish hue. 



At 12h. 30', there was an arch in the south about 15° high, and various irre- 

 gular masses of light in the north, the rest of the sky being of a deep blue. 

 At 2h. the sky very clear. At this time the Aurora was very brilliant, and 



