66 



ON THE PERIODICITY OF THE AURORA BOREALIS. 



Mar. 9. 



" 13. 



* 23. 



" 28. 



" 28. 

 Apr. 8. 



" 10. 



" 18. 



" 19. 

 May 3. 



" 21. 



" 23. 



" 25. 

 June 6. 



" 7. 

 July 7. 

 Aug. 14. 

 Sept. 3. 



" 4. 



" 4. 

 5. 



" 5. 



" 5. 



" C. 

 8. 



" 9. 



" 12. 



" 16. 



" 16. 



" 16. 



« 19. 



" 22. 



« 23. 



" 24. 



" 25. 



Oct. 3. 



6. 



« 7. 



" 27. 

 Nov. 16. 



Dec. 16. 



Jan. 13. 



" 28. 



" 28. 



" 28. 



" 28. 



Brussels. 



Franeker. 



Brussels. 



Brussels. 



Brussels. 



Brussels. 



Franeker. 



St. Petersburg. Euler. 



Montmorenci. Cotte. 



Franeker. Cotte. 



Montmorenci. Cotte. 



St. Petersburg. Euler. 



Montmorenci, Franeker, and Brussels. Cotte. 



Brussels. Cotte. 



Cambridge. Winthrop. Lovering. 



Franeker. Cotte. 



Cotte. 

 Cotte. 



Cotte. 



Cotte. 



Cotte. 



Cotte. 

 Cotte. 



Montmorenci and Franeker. Cotte. 

 St. Petersburg. Euler. 

 Cambridge. Winthrop. Lovering. 

 Franeker. Cotte. 

 Cambridge. Winthrop. Lovering. 

 Franeker and Montmorenci. Cotte. 

 Berlin. Beguelin. St. Petersburg. Euler. 

 Franeker. Cotte. 

 St. Petersburg. Euler. 

 St. Petersburg. Euler. 

 Franeker. Cotte. 

 Cambridge. Winthrop. Lovering. 

 Montmorenci, Brussels, and Franeker. Cotte. 

 St. Petersburg. Euler. Bordeaux. Cotte. 

 St. Petersburg. Euler. 

 Montmorenci and Brussels. Cotte. 

 Franeker. Cotte. St. Petersburg. Euler. 

 Franeker. Cotte. 

 Brussels. Cotte. 

 Franeker. Cotte. 

 St. Petersburg. Euler. 

 St. Petersburg. Euler. 

 Franeker. Cotte. 



Franeker. Cotte. Berlin. Beguelin. 

 Franeker. Cotte. 



1777. 



Montmorenci. Cotte. 

 Cambridge. Winthrop. Lovering. 

 Dighton, Mass. Stiles. Loomis. 

 Franeker and Holland. Cotte. 

 St. Petersburg. Euler. 1 



i Acta Sci. Acad. Petrop. 1777, Pt. 2, p. 395. 



" 8. 



8. 



9. 



Feb. 19. 



Holland. Cotte. 



Montmorenci and Franeker. Cotte. 



St. Petersburg. Euler. 



St. Petersburg. Euler. 



Holland. Cotte. 



Montmorenci and Holland. Cotte. 



St. Petersburg. Euler. 



Holland. Cotte. 



Berlin. Beguelin. Jena. Zeissing. 



Paris. Detienne and Pingre. Reuss. 1 



Montmorenci and Franeker. Cotte. 



Amsterdam. Cotte. 



Montmorenci. Cotte. 



Berlin. Beguelin. St. Petersburg. Euler. 



Dighton, Mass. Stiles. Loomis. 



Montmorenci. Cotte. 



St. Petersburg. Euler. 



Franeker, Brussels, and Holland. Cotte. 



St. Petersburg. Euler. 



Franeker. Van Swinden. Cotte. 



St. Petersburg. Euler. 



Franeker. Van Swinden. Cotte. 



Franeker and Amsterdam. Cotte. 



St. Petersburg. Euler. 



St. Petersburg. Euler. 



Franeker. Van Swinden. Amsterdam. Cotte. 



St. Petersburg. Euler. 



Berlin. Beguelin. 



Cambridge. Winthrop. Lovering. 



Franeker and Holland. Cotte. 



Berlin. Beguelen. 



Holland. Cotte. 



Brussels. Cotte. St. Petersburg. Euler. 



Berlin. Beguelin. Franeker. Van Swinden. 



Holland and Brussels. Cotte. 



St. Petersburg Euler. 



Berlin. Beguelin. Franeker. Van Swinden. 



St. Petersburg. Euler. 



Holland and Brussels. Cotte. 



Cambridge. Winthrop. Lovering. 



Montmorenci. Cotte. St. Petersburg. Euler. 



Franeker. Van Swinden. 



Holland and Brussels. Cotte. 



Franeker. Van Swinden. 



St. Petersburg. Euler. 



Holland and Brussels. Cotte. 



Franeker. Van Swinden. Berlin. Beguelin . 



Franeker. Cotte. 



■ Journ. de Phys. IX. 272 and 275. 



