ON THE PERIODICITY OF THE AURORA BOREALIS. 



257 



Nov. 12. Prague? Wolf. 1 

 " 23. Worcester. Woodward. 



1840. 



Baltischport. Kupffer. 

 Bussia. Wolf. 2 

 Worcester. Woodward.* 

 Worcester. Woodward. 

 Worcester. Woodward. 

 Worcester. Woodward. 

 Baltischport. Kupffer. 

 Baltischport. Kupffer. 

 Baltischport. Kupffer. 

 Baltischport. Kupffer. 

 Worcester. Woodward. 

 Baltischport. Kupffer. 

 Baltischport. Kupffer. 

 Baltischport. Kupffer. 

 Worcester. Woodward. 

 Worcester. Woodward. 

 Worcester. Woodward. 

 Philadelphia. Bache. 4 

 Worcester. Woodward. 

 Philadelphia. Bache. 

 Worcester. Woodward. 

 Worcester. Woodward. 

 St. Petersburg. Wolf. 5 

 Worcester. Woodward. 8 

 Philadelphia. Bache. 

 Worcester. Woodward. 

 Worcester. Woodward. 

 Worcester. Woodward. 

 Philadelphia. Bache. 

 Toronto. Sahine. Wolf. 

 Baltischport. Kupffer. 

 Worcester. Woodward. 

 Worcester. Woodward. 

 Worcester. Woodward. 

 Worcester. Woodward. 

 Worcester. Woodward. 

 Baltischport. Kupffer. 

 Baltischport. Kupffer. 



1 Prager Beobachtungen, 1839. 



2 Bull, de l'Acad. Brux. X. 9. 



s Med. and Surg. Journal, XXII. 20, 148, 212, 292, and 355. 



' Magnet, and Meteor. Obserr. Girard College, 51. 



5 Bull, de l'Acad. Brux. IX. 617. 



« Medical and Surg. Journal, XXIII., 87, 231, 296, and 376. 



vol. x. 33 



Dec. 



* a 



19. Worcester. Woodward. 



20. Baltischport. Kupffer. 



21. Worcester. Woodward. 

 21. Baltisclqwrt. Kupffer. 

 2S. Worcester. Woodward. 

 29. Worcester. Woodward. 



1841. 

 Wolf. 1 



Worcester. Woodward. 2 

 Worcester. Woodward. 

 Worcester. Woodward. 

 Toronto. Sabine. Wolf. 

 Toronto ? Sahine. Wolf. 

 Baltischport. Kupffer. 

 New Haven. Wolf. 8 

 Baltischport. Kupffer. 

 Prague ? Wolf. 

 Prague ? Wolf. 

 Prague? Wolf. 

 Prague ? Wolf. 

 Prague ? Wolf. 

 Prague ? Wolf. 

 Prague ? Wolf. 

 Prague. Wolf. 

 Worcester. Woodward. 4 

 Prague ? Wolf. 

 Prague? Wolf. 

 Prague? Wolf. 



1842. 

 ♦Jan. 1. Baltischport. Kupffer. 

 ♦March 17. Baltischport. Kupffer. 

 ♦April 10. Baltisc/q)ort. Kupffer. 

 ♦July 11. Toronto. Sabine. Wolf. 5 

 Sept. 16. Toronto. Sabine. Wolf. 



1843. 

 ♦Feb. 4. Sitka. Kupffer. 

 *April 17. Sitka. Kupffer. 6 



1 Bull, de l'Acad. Brux. X. 9. 



2 Med. and Surg. Journal, XXIV., 20 and 83. 



3 Bull, de l'Acad. Brux. VIII, 64 



* Med. and Surg. Journal, XXV., 295. 



5 Magnetic and Meteorolog. Observations, Toronto, I. 313. 



6 At Lougan, from the 16th of March for fifteen days, and 

 from 5 p.m. to midnight, a white light, similar to the aurora 

 borealis, was observed extending in a column from S.E. to 

 N. W. — Annuaire Magnet, et Meteor, de Russie, 1843, p. 451 

 See, also, pp. 508 and 533. 



