ON THE PERIODICITY OF THE AURORA BOREALIS. 



67 



Apr. 9. 



Holland and Brussels. Cotte. 

 St. Petersburg. Euler. 

 Cambridge. Winthrop. Lovering. 

 St. Petersburg. Euler. 

 Holland. Cotte. 



Franeker. Holland, Amsterdam, fyc. 

 Spain. Larrea. Rico. 

 Leicarden. Cotte. 



Van Swinden. Cotte. 

 Van Swinden. Cotte. 

 "Winthrop. Lovering. 

 Cotte. 



"Winthrop. Lovering. 

 Stiles. Looniis. 



Cotte. 



Franeker. 

 Franeker. 

 Cambridge 

 Franeker. 

 Cambridge 

 Portsmouth, N. H. 

 Franeker. Cotte. 

 Berlin. Beguelin. 

 Franeker and Breda. Cotte. 

 Montmorenci and Holland. Cotte. 

 Franeker, Montmorenci, and Holland. Cotte. 

 St. Petersburg. Euler. 

 St. Petersburg. Euler. 

 St. Petersburg. Euler. 

 Cambridge. Winthrop. Lovering. 

 Paris. Detienne. Boue. 1 

 Franeker and Montmorenci. Cotte. 

 St. Petersburg. Euler. 

 Cambridge. Winthrop. Lovering. 

 Portsmouth, N. H. Stiles. Loomis. 

 Berlin. Beguelin. St. Petersburg. Euler. 

 Franeker, Montmorenci, and Holland. Cotte. 

 Perpignan. Cotte. 

 Franeker. Cotte. 

 St. Petersburg. Euler. 

 Geneva. Deluc. 2 



Cambridge. "Winthrop. Lovering. 

 Franeker. Van Swinden. Cotte. 

 Franeker. Van Swinden. Cotte. 

 Spain. Larrea. Eico. 

 Franeker and Holland. Cotte. 

 Montmorenci. Cotte. 

 Franeker. Van Swinden. 

 Franeker. Van Swinden. Cotte. 

 Cambridge. Winthrop. Lovering. 

 Berlin. Beguelin. Jena. Zeissing. 

 Franeker, Montmorenci, and Austria. Cotte. 

 Vienna. Pilgram. Paris. Messier. Reuss. 8 

 Berlin. Beguelin. Jena. Zeissing. 



1 Jonrn. de Phys. X. 231-3. 



2 Bull, de l'Acad. Brux. 1842. Pt. 2. p. 6. 

 8 Mem. de l'Acad. 1770, p. 440. 



Nov. 3. Vienna. Pilgram. 



" 6. Holland. Cotte. 



" 7. Franeker and Holland. Cotte. 



" 9. Holland. Cotte. 



" 21. Franeker and Holland. Cotte. 



" 23. Holland. Cotte. 



" 27. Cambridge. WintHrop. Lovering. 



" 27. Portsmouth, N. H. Stiles. Loomis. 



" 27. Jena. Zeissing. St. Petersburg. Euler. Reuss. 1 



" 27. Franeker, Montmorenci, Holland, Sfc. Cotte. 



" 27. Virginia. Madison. 5 



" 28. Cambridge. Winthrop. Lovering. 



Dec. 1. Holland. Cotte. 



" 2. Cambridge. Winthrop. Lovering. 



" 2. Portsmouth, V. H. Stiles. Loomis. 



" 2. Holland. Cotte. 



" 3. Berlin. Beguelin. Jena. Zeissing. 



" 3. Franeker, Montmorenci, fyc. Cotte. 



" 3. Vienna. Pilgram. Beziers. Bertholon. 



" 3. Berlin. Schulze. Reuss. 8 Vienna. Pilgram. 



" 3. Gurzelen. Spriingli. Wolf. 4 



" 4. Berlin. Beguelin. 



" 6. Vienna. Pilgram. 



" 6. Franeker, Montmorenci, and Holland. Cotte 



" 17. Holland. Cotte. 



" 18. Fra?ieker and Holland. Cotte. 



" 21. Cambridge. Winthrop. Lovering. 



" 27. Mannheim. Pilgram. 



" 30. St. Petersburg. Euler. 



" 31. Chinon. Cotte. 



1778. 



Jan. 18. Cambridge. Winthrop. Lovering. 



" 18. Franeker. Van Swinden. 5 



" 18. Copenhagen. Cotte. St. Petersburg. Eoler. 1 



" 19. Portsmouth, N. H. Stiles. Loomis. 



" 19. Holland. Cotte. St. Petersburg. Euler. 



" 20. Franeker. Van Swinden. Holland. Cotte. 



" 20. St. Petersburg. Euler. 



" 21. Franeker. Van Swinden. 



" 21. Montmorenci and Holland. Cotte. 



" 21. St. Petersburg. Euler. 



1 Acta Sei. Acad. Petrop. 1777, Hist. Pt. II. p. 71. 



2 Amer. Phil. Trans. II. 123. 



3 Me'm. de l'Acad. Berlin. 1777, p. 106. 



4 Mitt. Naturforsch. Gcsell. Bern. 1855, p. 43. 



5 Me'm. de l'Acad. Brux. III. 449. 



s.Acta Sci. Acad. Petrop. 1778, Pt. II. p. 358. 



