620 



APPENDIX. 



[No. III. 



zenith, to carry on the similitude, the folds of the curtain proceeded in se- 

 veral beautiful festoons towards the north and south, and had occasionally 

 a slow motion, as if it were folding and unfolding again and again. The 

 moon at this time shone with a bright light and illuminated several layers 

 of cloud (cirro-stratus) in the N.E,, every other part of the sky being un- 

 clouded. 



At 2h. a. m., a large homogeneous sheet of rare light was spread over 

 20 degrees on each side of the zenith, and near the horizon there were many 

 layers of cirro-stratus, some of them pretty dense, so as to obscure the 

 moon when they passed over its face. The rapid was quite inaudible at 

 this time. 



December 27th, 1820. 



Hour. Temp. Wind. 



9 —42 Calm, Slight fog, rapid very loud. 



10 -43 do. do. 



Noon —40 N.E. Light. Zenith cloudless — light grayish blue — stratus 



creeping along the valleys — fine day. 

 9 -45 N.E. Light. Clear. 



1 1 do. Rapid, very loud. 

 Midnt. -45 



At llh. p. m.,the sky clear, the moon not yet risen, but many stars visible. 

 A beam of light, about 8° broad, rose from 10° above the horizon in the 

 S.E.b.S., and gradually becoming fainter upwards, disappeared a little south 

 of the zenith. After continuing stationary for some time, it sent forth a beam 

 of light from its south-east end, which extended 11° more to the northward, 

 whilst its fainter end was at the same instant prolonged, so as to form a com- 

 plete arch, terminating in the N.W. b. W. horizon. A little haze was visible 

 at this time in the southern horizon. 



At midnight the Aurora formed a somewhat interrupted circle round the sky, 

 about 15° high, which sent down from its N.W. b. W. and S.E. points, several 

 pointed processes which nearly touched the horizon. Some large flexuose 

 streaks, and masses of light traversing the zenith, connected the northern with 

 the southern part of the circle ; and there were also a few detached irregular 



