Mr Potter on the Aurora Borcalis. 23 



that he did not, as he promised, " attempt to perform it indepen- 

 dent of every hypothesis, hy a direct appeal to experiment and 

 observation. 11 * I remain, my Dear Sir, ever most truly yours, 



James D. Forbes. 

 5th March 1831. 

 To Dr Brewster. 



Art. III. — Obse?vations on the Meteor called the Aurora Bo* 

 realisywith Calculations, Trigonometrical and Analytical, to- 

 wards determining the position and the course of the Arches, 

 with respect to the surface of the Earth. By It. Potter, 

 Esq. Junior. Communicated by the Author. 



T.HE magnificent meteor called the Aurora Borealis has been 

 one which has awakened throughout all ages the feelings of 

 wonder and astonishment in the minds of mankind. Amongst 

 the superstitious it has been always regarded as an omen of 

 fearful portent, betokening the most awful calamity to the in- 

 habitants of the earth ; and though we now look at it with a 

 philosophic eye, and speculate on its connections with electricity 

 and magnetism, its wonderful and ever-varying forms of 

 shining nebulous masses, of spiring evanescent streamers, or 

 more lasting and not less magnificent arches, with the brilliant 

 tints which it occasionally assumes, excite still in us amaze- 

 ment and delight whilst viewing it as an exhibition of one of 

 nature"^ operations on a scale which our imagination in vain 

 endeavours to grasp. It is no matter of surprise, then, that 

 since the revival of learning, this meteor should have often at- 

 tracted the attention of philosophers to consider its nature and 

 causes, and, in connection with these, its position in space, or 

 its height above the surface of the earth : indeed, until we can 

 with some precision determine its locality, it is in vain to spe- 

 culate on the extent of its dependence, either on the atmo- 

 sphere or even the more ponderable parts of our planet; and 

 hence to determine its height is the first step we can take in 

 the investigation, and it is a matter of disgrace to science at 

 this day that such discordant opinions should prevail amongst 

 scientific men on the subject. 



Polai Regions, p, ;. 



