RECORD OF AURORAL PHENOMENA. 29 



which remained until 45 minutes after midnight, and then disappeared at bearing 99°. Motion 

 of the needle westward. 



10th. At midnight, an arch resembling a horse-shoe, the extremities of which bore 99° and 76°. 

 From each of these points streams were projected across the zenith towards 290°, but they did 

 not reach the opposite horizon. They were of a faint grayish-yellow color. The stars shone 

 brilliantly through the columns of light. Moon very bright. The needle was not the least 

 affected. I have observed that the needle is usually most disturbed by the appearance of the 

 Aurora in dense hazy weather. 



11th. At 3h. p. m., a cloud extended in an arch from 99° to 279°, elevated 30°, which bore a 

 strong resemblance to the Aurora, particularly at the end at 279°, from whence some beams 

 were projected towards the zenith. The needle was not affected. 



12th. At 8h. 30m. p. m., faint curved streams in the zenith. At 9h., an arch from 99° to 279°, 

 exactly similar in shape to the cloud seen yesterday. The color resembled the halo round the 

 moon. The needle was not affected. At llh. 40m., the coruscations occupied a considerable 

 portion of the northern part of the sky, lying in parallel arches from 76° to 279°. The centre 

 one was brilliant, and the motion, resembling a volume of smoke, passed from the former bearing 

 towards the latter. Some arches appeared in the zenith lying 65° and 245°, and flashes darted 

 with instantaneous motion from these towards the point to which their extremities were directed. 

 The needle betrayed a slight motion eastward. At 12h., a broad band of light from 302° to 

 54°, elevated 20°. 



13th. The atmosphere was so dense this night that the stars were completely obscured, and the 

 edges of the moon could only be faintly traced through the haze. At 9h. p. m., there was not 

 any appearance of the Aurora, and the needle rested at 348° 30', its usual position at this hour 

 when undisturbed by the Aurora. At llh. 30m., faint streams of light gleamed through a 

 large portion of the heavens, both in the zenith and near the horizon, and immediately afterwards 

 brilliant coruscations burst forth of the most agitated kind. At llh. 40m., a horizontal stream 

 extended from 279° to 31°, and the anterior motion, similar to rolling smoke, passed from the 

 first point to the latter. The needle was now drawn 3° 30' to the eastward, or as far as 345° 

 00'. At llh. 50m., there appeared another stream of irregular shape, which proceeded from 

 279° in a line nearly parallel to the horizon, until it curled round at 9°, or near the direction of 

 the magnetic meridian. The interior motion flashed along this stream with the utmost rapidity. 

 The needle moved now to 343° 50', or 4° 40' eastward of its first position; and, during the 

 appearance of this coruscation, I perceived the needle to oscillate between 343° 50' and 344° 

 40' ; and it may be remarked this was the only occasion on which a vibratory motion was 

 observed. On the disappearance of this display, brilliant semicircular curves were presented in 

 the same quarter, ornamented with all the prismatic colors. At llh. 55m., the needle had 

 receded westward as far as 347° 00'. The important fact of the existence of the Aurora at a 

 less elevation than that of dense clouds, was evinced on two or three occasions this night, and 

 particularly at llh. 50m., when a brilliant mass of light, variegated with the prismatic colors, 

 passed between an uniform, steady, dense cloud and the earth; and, in its progress, completely 

 concealed that portion of the cloud which the stream of light covered until the coruscation had 

 passed over it, when the cloud appeared as before. 



The observations of this evening seem to corroborate the remark which I had previously made, 

 that the direction in which the needle moves appears to depend on the position in which streams 

 of Aurora are placed, and the quantity of the effect upon its proximity to, or distance from, the 

 earth. When the extremities of arches lay near the bearings of 234° and 54°, the needle moved 

 eastward; and when near the bearings 324° and 144°, or 279° and 99°, the motion of the 

 needle was westward. Both of these facts were shown to-night. At the first display, when the 

 extremities of the arches pointed near 234° and 54°, and the interior motion followed the 

 same direction, the needle moved eastward as far as 345° 00' ; but after midnight, the corusca- 

 tions ceased to appear in that direction, and, at 12h. 10m., were presented in three arches, 

 traversing the zenith, whose extremities pointed 121° and 302°; the needle then receded towards 

 the west, and rested at 349° 30', having varied its position 5° 40' in the course of twenty 

 minutes. 



