ON THE PERIODICITY OF THE AURORA BOREALIS. 



135 



Apr. 4. 

 " 5. 

 " 5. 



5. 



6. 



6. 

 " 6. 

 " 6. 



7. 

 " 11. 

 " 14. 

 " 15. 

 " 17. 

 " 19. 

 " 22. 

 " 23. 

 " 25. 

 May 6. 

 " 6. 

 " 7. 

 " 9. 

 " 13. 

 " 17. 

 « 23. 

 " 25. 

 " 29. 

 June 3. 

 " 8. 

 " 13. 

 " 15. 

 " 22. 

 " 27. 

 " 29. 

 " 30. 

 " 30. 

 " 30. 

 July 1. 

 " 2. 

 " 4. 

 " 7. 

 " 19. 

 " 25. 

 " 25. 

 " 25. 

 " 30. 



New York. Hough. 



New York. Hough. Toronto. Sabine. 



Brussels. Quetelet. Hamburg. Schmidt. 



Makersloun. Broun. Edinburgh. 



New Haven. Herrick. Newton and Loomis. 



New York. Hough. Providence. Caswell. 



Toronto. Sabine. Brussels. Quetelet. 



Gotliaab. Block. 



Makerstoun. Broun. 



New York. Hough. 



Gothaab? Block. 



New York. Hough. 



Hansteen, 



Hough. 



Hough. 



Gothaab. Block. 



Christiania 

 New York. 

 New York. 

 Edinburgh} 

 Dunse. Stevenson. 

 Brussels. Quetelet. Greenwich. 

 Collingwood. Herschel. France 



Airy. 2 

 Arago. 8 



New York. Hough. Philadelphia. Bache. 



Brussels. Quetelet. 



New York. Herrick. Newton and Loomis. 



Litchfield, Conn. Herrick. Newton and L. 



Goshen, Conn. Herrick. New Haven. Bradlee. 



New York. Hough. 



New York. Hough. 



Hough. 



Hough. 



Hough. 



Hough. 



Hough. 

 Bache. 



New York. 



Neio York. 



New York. 



New York. 



New York. 



Philadelphia. 



New York. Hough. 



New Haven. Herrick. Newton and Loomis. 



Philadelphia. Bache. 



New York. Hough. 



New York. Hough. 



New York. Hough. 



New York. Hough. 



Philadelphia. Bache. 



New York. Hough. 



New Haven. Herrick. Newton and Loomis. 



New York. Hough. Newberry. Johnson. 



Philadelphia. Bache. Toronto. Sabine. 



New York. Hough. 



Toronto. Sabine. 



Toronto. 

 Toronto. 



Sabine. 

 Sabine. 



' Edin. Phil. Journ. 1844, p. 378. 



2 Greenwich Magnet, and Meteor. Observ. 1843, p. 251. 

 8 Compt. Rend. XVI. 1092. Athenaeum, 1843, p. 465. 

 4 Bull, de l'Acad. Brux. XII. Pt. I. 532. 



July 31. 

 Aug. 3. 



" 3. 



" 3. 



" 12. 



" 22. 



" 26. 

 Sept. 1. 



" 2. 



" 9. 



" 10. 



" 13. 



" 14. 



" 15. 



" 18. 



" 18. 



" 18. 



" 19. 



" 20. 



" 21. 



" 21. 



" 22. 



" 22. 



" 24. 



" 25. 



" 26. 



" 27. 



" 27. 



" 27. 



" 28. 



« 28. 



" 29. 



" 30. 



" 30. 

 Oct. 2. 



" 5. 



" 9. 



" 14. 



" 14. 



" 14. 



" 15. 



" 15. 



" 16. 



" 16. 



" 18. 



" 19. 



Neio York. 

 Cambridge. 

 New York. 

 Hamburg. 

 Neio York. 

 Neio York. 

 Gothaab 



Hough. 

 Bond. 

 Hough. 

 Schmidt. 

 Hough. 

 Hough. 

 Block. 



Lovering. 

 Toronto. 



Sabine. 



Edinburgh. Paul. 1 



Christiania. Hansteen. Gothaab. Block. 



Christiania. Hansteen. Gothaab. Block. 



New York. Hough. 



Gothaab. Block. 



New Haven. Herrick. Newton and Loomis. 



Gothaab. Block. 



Gothaab. Block. 



New Haven. Bradley. Newton and Loomis. 



New York. Hough. Toronto. Sabine. 



Christiania. Hansteen. Makerstoun. Broun. 



Christiania. Hansteen. Makerstoun. Broun. 



New York. Hough. 



Christiania. Hansteen. Gothaab. Block. 



Makerstoun. Broun. 



Christiania. Hansteen. Gothaab. Block. 



Jakobshavn. Rudolph. 



Gothaab. Block. 



Gothaab. Block. 



Christiania. 

 Cambridge. 

 New Haven 

 New York. 

 Cambridge. 

 Gothaab. Block. 

 New York. Hou 



Hansteen. 

 Bond. Lovering. 



Herrick. Newton and Loomis. 

 Hough. Providence. Caswell. 

 Bond. Lovering. 



Jakobshavn. Rudolph, 

 h. Toronto. Sabine. 



Johnson. 



New York. Hough. Neioberry. 



Gothaab. Block. 



Jakobshavn. Rudolph. 



New York. Hough. 



New York. Hough. 



Cambridge. Bond. Lovering. 



New Haven. Herrick. Newton and Loomis. 



Christiania. Hansteen. 



Lake Athabasca. Lefroy. 3 



Makerstoun. Broun. Christiania. Hansteen. 



Lake Athabasca. Lefroy. 



Makerstoun. Broun. 



Jakobshavn. Rudolph. 



New York. Hough. 



1 Edin. Phil. Journ. 1844, p. 378. 



2 Magnet, and Meteor. Observ. at Lake Athabasca, &c. p. 147. 



