SOO On the supposed injiuence of the Aurora, ^c. 



in latitudes more northerly than his own, and this fact has 

 been triumphantly submitted to the Academy of Sciences as a 

 confirmation of the views that we have been controverting. 

 The opinions, however, which we maintain are not in the 

 .slightest degree affected by any such observations, the truth 

 of which we have no hesitation to admit ; but even if a thousand 

 observers on a thousand different meridians were to observe 

 similar coincidences, they could only prove that certain AurorcB 

 are attended with agitations of the magnetic needle, — a propo- 

 sition of very different import from those which were submit- 

 ted to the Academy of Sciences on the 22d of January. 



In taking a general view of the different facts to which we 

 have had occasion to refer, we may consider them in two points 

 of view. 



1. If we regard it as proved, and we thiiik there is no fact 

 in physical science better established, that Aurorae occur which 

 have no influence on the magnetic needle ; that agitations of 

 the needle take place when no Aurorae are seen ; and that these 

 two phenomena sometimes appear simultaneously, — we must 

 then view them as the separate though occasionally co-existent 

 effects of some more general cause. But even if their co- 

 existence were not occasional but constant, this could never 

 prove that the one was the producing cause of the other; and it 

 would still be as probable as before that they were both refer- 

 able to a more general cause. What this cause is we do not 

 pretend to know ; but it has been and is the opinion of many 

 eminent philosophers, that both the luminous meteor and the 

 developement of magnetical action may have their origin in 

 certain disturbances in the electrical equilibrium of the at- 

 mosphere. 



2. Although we should have been disposed, previous to the 

 voyage of Captain Parry, to adopt the preceding views, yet 

 the observations of this distinguished navigator and of Lieu- 

 tenant Foster seem to have embarrassed the question with a 

 new difficulty. In the two months during which 2S Aurorae 

 occurred, the mean monthly excursions of the magnetic needle 

 on each side of its mean position was only 1° 37}'; whereas 

 during the two months when there were no Aurorae, it was 



