1G0 



ON THE PERIODICITY OF THE AURORA BOREALIS. 



« 



u 



Aug 



June 5. 

 « 5. 

 " 5. 

 " 11. 

 « 27. 

 « 27. 

 " 27. 

 " 27. 

 July 2. 

 " 7. 

 " 13. 

 " 16. 

 « 17. 

 " 17. 

 « 17. 

 " 26. 



26. 



26. 



29. 



J- 8 - 

 " ~ 24. 



" 24. 



" 25. 



« 26. 



" 29. 



" 29. 



" 30. 



" 31. 



Sept. 1. 



« 3. 



« 4. 



« 4. 



« 4. 



« 4. 



« 6. 



« 6. 



6. 



" 7. 



« 7. 



« 7. 



« 7. 



" 7. 



« 7. 



" 10. 



« 13. 



Providence. Caswell. New York. Hough. 



New Haven. Herrick. Newton and Loorais. 



Litchfield. Hendrick. 



Litchfield. Hendrick. 



Cambridge. Bond. Lovering. 



New Haven. Bradley. Newton and Loomis. 



Litchfield. Hendrick. 



Providence. Caswell. New York. Hough. 



New York. Hough. 



Litchfield. Hendrick. 



New York. Hough. 



New York. Hough. 



Cambridge. Bond. Lovering. 



New Haven. Bradley. Newton and Loomis. 



Litchfield. Hendrick. New York. Hough. 



Cambridge. Bond. Lovering. 



New Haven. Bradley. Newton and Loomis. 



New York. Hough. 



New York. Hough. 



New York. Hough. 



Litchfield. Hendrick. 



Leipsic. Keller. Jahn. 



Lot. 61° N. Long. 54° W. Sutherland. 



Davis's Strait. Sutherland. 1 



Cambridge. Bond. Lovering. 



Litchfield. Hendrick. New York. Hough. 



Litchfield. Hendrick. 



New York. Hough. 



Newberry. Johnson. 



New Haven. Olmsted. 2 New York. Hough. 



Cambridge. Bond. Lovering. 



New Haven. Bradley. Newton and Loomis. 



Worcester. Chandler. Rochester. Dewey ? 



Christiania. Hansteen. Yakoutsk. Kupffer. 



Cambridge. Bond. Lovering. 



New Haven. Olmsted and Bradley. 



Litchfield. Hendrick. New York. Hough. 



Cambridge. Bond. Lovering. 



Worcester. Chandler. New York. Hough. 



New Haven. Bradley. Newton and Loomis. 



Litchfield. Hendrick. 



Yakoutsk and Barnaoul. Kupffer." 



Christiania. Hansteen. 



New Haven. Bradley. Newton and Loomis. 



New York. Hough. 



Oct. 



Sept. 14. 

 " 15. 

 " 16. 

 " 16. 

 " 24. 

 " 26. 

 " 27. 

 " 28. 

 " 29. 

 " 29. 

 « 29. 

 29. 

 29. 

 30. 

 30. 

 30. 

 1. 



" 1. 

 " 2. 

 2. 

 2. 

 2. 

 3. 

 " 3. 



" 4 - 



" 18. 



" 18. 



" 19. 



" 20. 



" 20. 



" 20. 



« 20. 



" 21. 



" 21. 



" 22. 



" 23. 



" 23. 



" 23. 



" 24. 



" 26. 



" 28. 



" 29. 

 Nov. 11. 



" 1 5. 



" 17. 



Litchfield. Hendrick. 



Jahn. 



« Journal of a Voyage, &e. II. 346. 

 2 Amcr. Journ. Sci. Second Series, XII. 442. 

 » Annal. do l'Obsenr. Phys. Centrale de Russie, 1851, p. 213 

 and p. 575. 



New York. Hough. 



New York. Hough. 



Newberry Johnson. 



New York. Hough. 



New York. Hough. 



Aix-la- Chapelle. Heis. 



Hammerfest. Noodt. 



New York. Hough. 



New Haven. Olmsted. Providence. Caswell. 



Worcester. Chandler. South Carolina.Gibbes. 



St. Petersburg. Kupffer. 1 Rochester. Dewey. 



Newberry. Johnson. Georgia. LeConte. 2 



Christiania. Hansteen. 



St. Petersburg. Kupffer. 



Kamens. Vogel. Jahn. Prague? 



Neunkirchen. Lichtenberger. Jahn. 



New Haven. Bradley. Newton and Loomis. 



New York. Hough. 



Cambridge. Bond. Lovering. 



New Haven. Herrick. Newton and Loomis. 



New York. Hough. Providence. Caswell. 



Brussels. Quetelet. Yakoutsk. Kupffer. 



Bonn. Schmidt. Dresden. Jahn. 



Heis. Jahn. 



Hammerfest. Noodt. 



Newberry. Johnson. New York. Hough. 



Bonn. Schmidt. 



New York. Hough. Christiania. Hansteen. 



Cambridge. Bond. Lovering. 



Worcester. Chandler. Providence. Caswell. 



New Haven. Herrick. Newton and Loomis. 



Litchfield. Hendrick. Newberry. Johnson. 



Worcester. Chandler. 



New York. Hough. Christiania. Hansteen. 



New York. Hough. 



Cambridge. Bond. Lovering. 



New Haven. Herrick. Newton and Loomis. 



Litchfield. Hendrick. Providence. Caswell. 



Hammerfest. Noodt. 



New York. Hough. 



New Haven. Herrick. Newton and Loomis. 



Batty Bay. Kennedy. 4 



New York. Hough. 



Cambridge. Bond. Lovering. 



Jahn. 



1 Annnl. de 1'Observ. Phys. Centrale de Russie, 1851, p. 57. 



2 Amcr. Journ. Sci. Second Series, XIII. 128. 

 « Kreil's Jahrbuch fur Prag. III. 126-7. 



4 Procedings of Mr. W. Kennedy, &c. p. 86. 



