APPENDIX. 623 



task to decide on the correct one ; and all that was 

 evident to me, may be simply called two currents in 

 direct opposition, sometimes along double bands or 

 arches, and as often existing in a single arch, though in 

 the latter case I remarked that the paramount motion, if 

 from the westward, for instance, did not cease until it had 

 passed the zenith of its arc, and was encountered and 

 borne away by a superior eastern current. In the midst 

 of these conflicting phenomena I ran to the needle, and 

 found it almost steady as regarded the minute, which 

 was 0° 45' W., but so tremulous (see-sawing perpen- 

 dicularly) that it dipped (by estimation) full 10' of 

 the graduated arc of the instrument. On going out 

 again the appearances had changed, but were still 

 brilliant, and more spread between E.b.N. and S.E. 

 The two currents, however, were still obvious, and 

 though the aurora was what I should say comparatively 

 high to what it had been on other occasions, yet it not 

 only excluded the stars, which it may be remarked 

 were previously particularly bright, but when visible it 

 made them appear to be at an immense distance. On 

 the other hand, their twinkling suffered only partially 

 from the interposition of the pale and flaky aurora 

 which was evidently much higher than the principal 

 streams ; and it may not be out of place to mention, 

 that had I been unacquainted with the locality, I should 

 have positively averred that I heard a whizzing noise 

 during the rapidity of the motion, but which noise I 

 knew was the faint murmur of Anderson's Fall in 

 the river to the N.W. On returning to the needle 

 it had moved to 0° 50' W., but was very tremulous, 

 which may lead to a supposition that the same effect 

 may be produced by a similar (though invisible) cause 

 during the day; I mean, counter-currents of aurora. 



