ON THE PERIODICITY OF THE AURORA BOREALIS. 



95 



Dec. 13. Keytdal. Dalton. 



" 17. Stockholm. Nicander. 



« 19. Kendal. Dalton. 



" 23. Bmssels. Mann. 



" 26. New Haven. Stiles. Loomis. 



" 26. Brussels. Mann. Kendal. Dalton. 



" 27. Salem. Holyoke. Lovering. 



" 27. New Haven. Stiles. Loomis. Sagan. Preus. 



" 28. Brussels. Mann. 



" 29. Brussels. Mann. 



1792. 



Kendal. Dalton. 



Sagan. Preus. 



Kendal. Dalton. 



Sagan. Preus. Kendal. Dalton. 



Montreal} 



Sagan. Preus. 



Brussels. Mann. 



Stockholm. Nicander. 



Kendal. Dalton. 



Stockholm. Nicander. 



Stockholm. Nicander. 



Stockholm. Nicander. Kendal. Dalton. 



Stockholm. Nicander. 



Stockholm. Nicander.' 



Stockholm. Nicander. 



Kendal. Dalton. 



Mount St. Andex, Bavaria. Hochholzer. 



Stockholm. Nicander. 



Kendal. Dalton. 



Saga7i. Preus. 



Sagan. Preus. 



Stockholm. Nicander. 



Saga7i. Preus. 



Mannheim. Hemmer. 



Stockholm. Nicander. 



Mannheim. Hemmer. 



Kendal. Dalton. Isserstadt. Zeissing. 



Sagan. Preus. Stockholm. Nicander. 



Montmorenci. Cotte. 3 



Sagan. Preus. Stockholm. Nicander. 



Kendal. Dalton. 



Sagan. Preus. 



Mannheim. Hemmer. 



Sagan. Preus. 



Mannheim. Hemmer. Kendal. Dalton. 



Stockholm. Nicander. 



1 Mem. Amer. Acad. II. 115. 



2 Journ. de Phys. XL. 450. 



May 4. 



6. 



" 7. 



" 8. 



" 9. 



" 14. 



« 15. 



" 20. 



" 22. 



" 27. 



June 2. 



« 30. 



July 7. 



" 11. 



" 18. 



" 19. 



Aug. 2. 



" 4. 



" 17. 



" 23. 



" 27. 

 Sept. 1. 



" 6. 



" 14. 



« 22. 



" 28. 

 Oct. 2. 



" 12. 



" 13. 



" 13. 



« 13. 



" 13. 



" 13. 



" 14. 



" 14. 



" 15. 



" 16. 



" 17. 



" 18. 



" 19. 



" 23. 



« 31. 

 Nov. 7. 



" 13. 



" 14. 



" 17. 



« 29. 

 Dec. 2. 



Stockholm. Nicander. 

 Kendal. Dalton. 

 Stockholm. Nicander. 

 Brussels. Mann. 

 Sagan. Preus. 

 Sagan. Preus. 

 Mannheim. Hemmer. 

 Brussels. Mann. 

 Montmorenci. Cotte. 

 Brussels. Mann. 

 Sagan. Preus. 

 Kendal. Dalton. 



Salem. Holyoke. Lovering. 



Salem. Holyoke. Lovering. 



Salem. Holyoke. Lovering. 



Brussels. Mann. 



Mount St. Andex, Bavaria. Hochholzer. 



Kendal. Dalton. 



Mount St. Andex, Bavaria. Hochholzer. 



Kendal. Dalton. 



St. Petersburg. Euler. 1 



Mannheim. Hemmer. 



Mannheim. Hemmer. 



Mannheim. Hemmer. 



Kendal. Dalton. 



Mannheim. Hemmer. 



Stockholm. Nicander. 



Kendal. Dalton. 



Salem. Holyoke. Lovering. 



New Haven. Stiles. Loomis. Kendal. Dalton. 



New Haven. Stiles. Loomis. Sagan. Preus. 



Isserstadt. Zeissing. St. Petersburg. Euler. 



Marseilles. St. Jacques. Brussels. Mann. 



Salem. Holyoke. Lovering. 



Preus. Kendal. Dalton. 



Sagan. 

 Sagan. 

 Sagan. 

 Sagan. 

 Sagan. 



Preus. 



Preus. 



Preus. 



Preus. 

 Stockholm. Nicander, 

 Kendal. Dalton. 

 Kendal. Dalton. 

 Stockholm. Nicander. 

 Sagan. Preus. 

 Sagan. Preus. 

 Stockholm. Nicander 

 Kendal. Dalton. 

 Moscow. Stritter. 3 



Kendal. Dalton. 



i Nova Acta. Sci. Acad. Pctrop. X. 505. 

 2 Nova Acta. Sci. Acad. Petrop. X. 505. 



