ON THE PERIODICITY OF THE AURORA BOREALIS. 



71 



Nov. 18. Nanci. Cotte. 



" 25. St. Petersburg. Euler. 



" 27. Gurzehn. Sprungli. Wolf. 



Dec. 3. St. Petersburg. Euler. 



" 5. Brussels. Durondeau. Vienna. Pilgram. 



" 5. Montmorenci. Cotte. 



" 5. Franeher and Holland. Cotte. 



" 6. Montmorenci. Cotte. 



" 6. Franeher and Holland. Cotte. 



" 6. Brussels. Durondeau. 



" 8. Franeher. Cotte. 



" 9. Jena. Zeissing. St. Petersburg. Euler. 



" 10. Brussels. Durondeau. 



1780. 



St. Petersburg. Schroter and Euler. 1 



Franeher and Holland. Cotte. 



St. Petersburg. Schroter and Euler. 



Montmorenci. Cotte. 

 1 St. Petersburg. Schroter and Euler. 



All over Europe. Cotte. Spain. Rico. 2 



Jena. Zeissing. Beziers. Bertholon. 



Turin} Morozzo. Vienna. Pilgram. 



Padua. Toaldo. Reuss. 4 



Gurzelen. Spi'iingli. Wolf. 



Geneva. Deluc. 6 Berne. Studer. 



Turin. Morozzo. 6 Boue\ 



Perpignan. Cotte. 



Pleshow. De Brekling. 7 Reuss. Boue. 



New Haven. Stiles. Loomis. 



St. Petersburg. Schroter, and Euler. 



Montmorenci. Cotte. 



New Haven. Stiles. Loomis. 



Chinon. Cotte. 



Chinon. Cotte. 



Berlin. Beguelin. 



Jena. Zeissing. 



St. Petersburg. Schroter and Euler. 



D'Orbessan. Reuss and Boue. 8 



Montmorenci. Cotte. 



New Haven. Stiles. Loomis. 



' Acta Sci. Acad. Petrop. 1*80, p. 396. 



2 Mem. Acad. Cienc. Madrid. III. 77. 



8 Mem. de l'Aead. Toulouse. II. 20. 



4 Saggi Acad, di Padua. I. 78. 



6 Mitt. Naturforsch. Gesell. Bern. 1855, p. 44. 



• Me'm. de l'Aead. Turin. II. 328. 



' Acta Sci. Acad. Petrop. 1780, p. 15. 



8 Mem. de l'Aead. Toulouse. II. 26. 



June 24. 

 July 9. 

 " 11. 

 " 27. 

 " 28. 

 " 28. 

 " 28. 

 " 28. 

 " 28. 

 " 28. 

 " 29. 

 " 29. 

 Aug. 2. 

 " 27. 

 Sept. 2. 

 " 3. 

 " 4. 

 " 7. 

 " 10. 

 " 11. 

 " 21. 

 " 22. 

 " 22. 

 " 27. 

 Oct. 4. 

 6. 

 " 10. 

 " 24. 

 " 28. 

 " 30. 

 " 30. 

 Nov. x. 

 " 4. 

 " 14. 

 " 19. 



' 20. 



' 20. 



' 21. 



' 22. 



' 23. 



' 23. 



' 25. 



' 25. 



' 25. 



' 16. 



New Haven. Stiles. Loomis. 



New Haven. Stiles. Loomis. 



New Haven. Stiles. Loomis. 



New Haven. Stiles. Loomis. 



New Haven. Stiles. Loomis. 



Geneva ? Deluc. 1 Frankfort. Pilgram. 



Germany. Boeckman. 2 Spain. Rico. 



Jena. Zeissing. Reuss and Cotte. 



Italy. Volta. 8 Bildersael. Pilgram. 



Gurzelen. Sprungli. Wolf. Berne. Studer. 



New Haven. Stiles. Loomis. 



Europe. Cotte. 



New Haven. Stiles. Loomis. 



St. Petersburg. Schroter and 



Schroter 



Schroter 



Schroter 



Schroter 



Schroter 



Schroter 



and 

 and 

 and 

 and 

 and 

 and 



Euler. 

 Euler. 

 Euler. 

 Euler. 

 Euler. 

 Euler. 

 Euler. 



St. Petersburg. 



St. Petersburg. 



St. Petersburg. 



St. Petersburg. 



St. Petersburg. 



St. Petersburg. 



New Haven. Stiles. Loomis. 



Franeker and Montmorenci. Cotte. 



St. Petersburg. Schroter and Euler. 



Franeker and, Montmorenci. Cotte. 



St. Petersburg. Schroter and Euler. 



Jena. Zeissing. 



Barbadoes. Blane. Boue. 4 



St. Petersburg. Schroter and Euler. 



St. Petersburg. Schroter and Euler. 



New Haven. Stiles. Loomis. 



Franeker, Geneva, fyc. Cotte. 



New Haven. Stiles. Loomis 



Berlin. Cotte. 



Jena. Zeissing. 



New Haven. Stiles. Loomis. 



New Haven. Stiles. Loomis. 



St. Petersburg. Schroter and Euler. 



Franeker. Cotte. 



New Haven. Stiles. Loomis. 



New Haven. Stiles. Loomis. 



St. Petersburg. Schroter and Euler. 



New Haven. Stiles. Loomis. 



Gurzelen. Sprungli. Wolf. Berne. Studer. 



Franeker, La Eochelle, fyc. Cotte. 



St. Petersburg. Euler. 



i Bull, de l'Aead. Brux. IX. Pt. II. 6. 

 2 Me'm. de l'Aead. Berlin. 1780, p. 17. 

 8 Phil. Trans. LXXII. Pt. I. p.xv. 

 * Roy. Soc. Edin. I. 34. 



