1849] WRITINGS OF JOSEPH HENRY. 287 



ON THE AURORA BOREALIS.* 



(Proceedings American Association, Adv. of Science, vol. ii, pp. 11. 12.) 



August 14, 1849. 



Professor Henry said : The paper of Professor Secchi seems 

 to me to be one of considerable interest. It contains a num- 

 ber of ingenious suggestions, which may lead to new results. 

 One fact alluded to in this paper is highly important, and 

 though taken for granted since the days of Franklin, has 

 only lately been fully established. I allude to the connec- 

 tion of the Aurora with electricity. Besides the observation 

 mentioned in the preceding paper, I am informed by Mr. 

 Herrick, of New Haven, that an electrical action had been 

 observed at that place on the wires of the telegraph at the 

 time of the appearance of the Aurora. The same fact has also 

 been observed in England and on the continent, during the 

 last year. It is highly desirable to ascertain whether this 

 action is one of actual transfer of electricity from the space 

 at one end of the wire to that at the other, or whether it is 

 an inductive action of the Aurora at a distance, disturbing 

 for an instant the electrical equilibrium of the wire. This 

 could be readily determined by the character of the action 

 on the needle of a galvanometer. 



There was an Aurora last night visible at this place, which 

 exhibited some peculiarities not frequently observed, (so far 

 as I am informed) in this latitude. These were pointed out 

 to me by Dr. A. D. Bache, and are similar in a degree to the 

 appearances observed in Siberia. The Aurora, in these high 

 latitudes, frequently presents the appearance of a number of 

 concentric scrolls or curtains, the general axis of which is 

 parallel to the dipping-needle. The Aurora of last night 

 consisted, while we were observing it, of a number of par- 

 allel beams which together formed the skeleton of an arch 

 with an irregular curtain border at the lower edge. 



I may mention to the Association that the Smithsonian 

 Institution, in connection with an extended system of meteor- 



■* [Remarks on a conimunication by Professor Angelo Secchi, of George- 

 town College, D. C, to the Association, on "The Aurora Borealis."] 



