ON THE PERIODICITY OF THE AURORA BOREALIS. 



133 



July 3. 

 " 6. 

 " 9. 

 " 11. 

 « 12. 

 " 13. 

 " 20. 

 " 31. 

 Aug. 5. 



7. 

 " 9. 

 " 9. 

 " 10. 

 " 14. 

 " 23. 

 " 24. 

 Sept. 2. 



2. 

 " 2. 

 " 2. 

 " 2. 

 " 3. 

 " 4. 

 « 5. 

 " 8. 

 " 9. 

 " 10. 

 " 11. 

 « 12. 

 " 13. 

 " 14. 

 « 15. 

 " 18. 

 " 19. 

 " 20. 

 " 23. 

 " 25. 

 « 28. 

 " 28. 

 « 28. 

 29. 

 30. 



2. 



3. 



7. 



7. 



8. 



a 



a 



Oct. 



Brussels. Quetelet. 



New York. Hough. 



New York. Hough. 



New Haven. Herriok. Newton and Loomis. 



Toronto. Sahine. 



Neio York. Hough. 



Sitka. Kupffer. 



New York. Hough. Canada. Hough. 



New York. Hough. Canada. Hough. 



Christiania. 



Cambridge. 



Christiania. 



Christiania. 



Christiania. 



Neio Haven 



Gothaab. 



New Haven. 



Hough 



Hansteen. 

 Lovering. 



Hansteen. 



Hansteen. 



Hansteen. 



Herrick. Newton and Loomis. 1 

 Block. 



Herrick. Newton and Loomis. 

 Sahine. 



New York. Hough. Toronto. 

 Philadelphia. Bache. 

 Christiania. Hansteen. Sitka. Kupffer. 

 Hobarton. Sabine. Gothaab. Block. 

 Gothaab. Block. 

 Gothaab. Block. 

 Gothaab. Block. 

 Gothaab. Block. 

 Gothaab. Block. 

 Gothaab. Block. 



Gothaab. Block. Jakobshavn. Rudolph. 

 Jakobshavn. Rudolph. 

 Gothaab. Block. 

 Block. 

 Block. 

 Block. 



Hough. Gothaab. Block. 

 Hansteen. 

 Rudolph. 

 Rudolph. 

 Bond. Lovering. 

 Herrick. Newton and Loomis. 

 Hansteen. 



Gothaab. 



Gothaab. 



Gothaab. 



New York. 



Christiania. 



Jakobshavn. 



Jakobshavn. 



Cambridge. 



New Haven. 



Christiania. 



New York. 



Christiania. 



Gothaab. Block. 



Jakobshavn. Rudolph. 



France. Marcel. 2 Hough. 



Christiania. Hansteen. 



Christiania. Hansteen. Jakobshavn. Rudolph. 



Hough. 

 Hansteen. Gothaab. Block. 



i Bull, de l'Acad. Brux. X. Pt. II. p. 111. 

 2 L'lnstitut. Sci. Math. Phys. &c. X. 443. 



Oct. 9. 



" 13. 



" 15. 



" 16. 



" 17. 



" 18. 



" 23. 



" 27. 



" 28. 



" 29. 



" 29. 



" 30. 



" 81. 

 Nov. 1. 



" 2. 



" 3. 



" 3. 



" 4. 

 6. 



" 7. 



" 8. 



" 9. 



" 10. 



" 10. 



" 11. 



" 12. 



" 13. 



" 14. 



" 21. 



" 21. 



" 21. 



" 21. 



" 21. 



" 22. 



" 23. 



" 24. 



" 24. 



" 25. 



" 27. 



" 28. 

 Dec. 1. 



" 2. 



" 5. 



" 5. 



" 6. 



« 6. 



" 7. 



Gothaab. Block. 

 Neo York. Hough. 

 Christiania. Hansteen. 

 Parma. Colla. 

 Geneva. Wartmann. 1 

 Brussels. Quetelet. 

 Gothaab. Block. 

 Christiania. Hansteen. 



Christiania. 



New York. 



Christiania. 



Christiania. 



Gothaab. 



Gothaab. 



Hansteen. 

 Hough. 

 Hansteen. 

 Hansteen. 

 Block. 

 Block. 



Gothaab. Block. 

 Gothaab. Block. 



Gothaab. Block. 



New Haven ? Herrick. Newton and Loomis. 



Christiania. Hansteen. Jakobshavn. Rudolph. 



Christiania. Hansteen. 



New Haven'} Herrick. Newton and Loomis. 



Jakobshavn. Rudolph. 



Gothaab. Block. 



New York. Hough. Jakobshavn. Rudolph. 



Christiania. Hansteen. Gothaab. Block. 



Jakobshavn. Rudolph. 



Sitka. Kupffer. Jakobshavn. Rudolph. 



Gothaab. Block. 



Gothaab. Block. 



Gothaab. Block. 



Worcester, Mass. Woodward. 2 



New Haven. Herrick. Newton and Loomis. 



Philadelphia. Bache. 



New York. Hough. Newberry. Johnson. 



Christiania. Hansteen. 



Gothaab. Block. 



Gothaab. Block. 



New York. Hough. Paris. Bouvard. Arago. 8 



Gothaab. Block. 



Gothaab. Block. 



New York. Hough. 



Cambridge. Bond. Lovering. 



Gothaab. Block. 



Gothaab. Block. 



Christiania. Hansteen. 



Gothaab. Block. Jakobshavn. Rudolph. 



Christiania. Hansteen. Toronto. Sabine. 



Gothaab. Block. 



Gothaab. Block. 



1 L'lnstitut. Sci. Math. Phys. &c. X. 443. 



a Med. and Surg. Journ. XXVII. 324. 



8 L'lnstitut. X. 443. Connaiss. de Terns. 1846, p. 412. 



