No. III.] Da. RICHARDSON ON THE AURORA. 617 



for a short time. Neither continued above two or three minutes, and they 

 exhibited no quick motions, but merely brightened a little, undergoing at the 

 same time a slight dilatation. They appeared, however, and disappeared at 

 intervals until 2Jh. (a. m. 23,) when a haziness overspread the sky. 



Hour. Temp. Wind. 



December 23, 1820. 



9 -36 W.N.W. Moderate. Hazy. 

 10 -37 do. do. do. 



Noon —36 do. do. Clearer, bright sun. 



3 — 40 W. do. Clear, thick mist over the rapid. 



9 —41 do. do. Hazy in the horizon, clear in the 



zenith, rapid rather quiet. 

 Midnt. —45 do. do. clear. 



At 11 p. m., a faint arch of pale greenish light, about 10° broad, rose to the 

 height of 30°, one of its limbs, bearing S.E.b. S., sprung from a collection of 

 whitish clouds, (cirri,) situated about 10° above the horizon. The other, 

 bearing W.b. N., faded away imperceptibly in a dark part of the sky, where 

 there were neither clouds nor stars visible. 



The moon was surrounded by a bur, and did not give much light. At 1 2, 

 the arch was still visible, but several strata of pretty dense white clouds 

 now occupied the southern part of the sky to the height of 20°, and the extre- 

 mities of the arch, which were broader and fainter than before, bore S.b. E. 

 and W.N.W. In the middle of the arch there were several gentle elevations 

 and depressions ; but although the light occasionally brightened up in some 

 spots, there were no quick motions amongst its parts. 



The state of the atmosphere continued, as before, pretty clear in the zenith, 

 but the bur round the moon, of a faint gray colour, with a slight tinge of orange 

 on its outer edge, remained. A similar bur was formed round a candle, its dia- 

 meter enlarging rapidly as the observer receded from it. 



Hour. Temp. Wind. 



December 24th, 1820. 



A.M. 9 —43 N.W. Light. Clear. Bur round the moon. Thin 



mist from the rapid. 



Noon. —37 S.W.b.S. do. Hazy. Sun seen obscurely. Rapid 



very great. 



P.M. 9 —40 W. Moderate zenith. Clear, horizon hazy. 



Midnt. —39.8 do. ' do. do. 4 k 



