(J04 APPENDIX. 



The needle was perfectly steady at 0° 12' E., but on 

 returning to the house, I could not avoid remarking a 

 dull reddish beam that darted up from E. b. N., and to 

 which the others near it seemed attracted. It increased 

 in brightness at its nearest point to the horizon, which 

 was about 8° high. The western part of the arch 

 previously mentioned became faint, and though dis- 

 tinctly perceptible, yet it was evident by its streaming 

 towards the red beam that it was concentrating at the 

 east. I immediately returned to the needle, and found 

 it had changed from 0° 12' E. to 0° 24/ E., where it 

 remained, as did the aurora also in the same place. 



January 15th. — At l h p.m., on looking at the needle 

 it appeared to be stationary at 0° 8' W., but on con- 

 tinuing to look, without altering my position, I could 

 detect it moving with the utmost steadiness, and so 

 gently as would have escaped common observation : it 

 was a full minute in retrograding to 0° 00', and it again 

 advanced to 0° 5' W. The weather was almost calm, 

 or there might be said to be the lightest air from 

 E. N. E. ; the sky was blue, perfectly clear, and the 

 sun so bright, as to make 16° difference between the 

 thermometer exposed to its rays and that in the shade, 

 which was —46°. As I wished to convince myself if 

 my own person had not caused the motion, though I 

 could not see how it should, since the motion was hori- 

 zontal, and my position was in almost a direct line with 

 the axis of the needle, I applied my finger to the 

 glass immediately before and on a level with the needle, 

 and the instantaneous effect was that of a violent per- 

 pendicular, or what I have hitherto called a tremulous, 

 action, which dipped half the depth of the needle below 

 the graduated arc of the instrument. This did not 

 affect the reading, which was still the same, viz. 0° 5' W. 



