ON THE PERIODICITY OF THE AURORA BOREALIS. 



69 



Sept. 23. Copenhagen and Dijon. Cotte. 



" 24. Cambridge. Winthrop. Lovering. 



" 24. Neic Haven. Stiles. Loomis. 



" 24. Dijon, $c. Cotte. 



" 25. New Haven. Stiles. Loomis. 



" 27. Holland. Cotte. 



" 30. St. Petersburg. Euler. 



" 30. Berlin. Beguelin. 



Oct. 9. Holland. Cotte. 



" 14. Franeler. Van Swinden. Berlin. Beguelin. 



" 14. Montmorenci, Holland, &rc. Cotte. 



" 14. Louvain. Chevalier. 



" 15. Holland. Cotte. 



" 19. Holland. Cotte. 



" 23. Franeler. Van Swinden. Cotte. 



" 25. Spain. Rico. 1 



" 26. Holland. Cotte. 



" 27. Holland. Cotte. 



Nov. 20. St. Petersburg. Euler. 



« 24. Holland. Cotte. 



Dee. 3. Bertholon. 2 



" 6. St. Petersburg. Euler. ■ 



" 7. Holland. Cotte. 



" 8. Franeler. Van Swinden. Cotte. 



" 10. St. Petersburg. Euler. 



" 13. Jena. Zeissing. St. Petersburg. Euler. 



" 14. Troies. Cotte. 



" 15. Holland. Cotte. 



" 17. Franelcer. Van Swinden. 8 Cotte. 



■ 17. St. Petersburg. Euler. 



" 26. Montmorenci. Cotte. 



1779. 



Jan. 6. Brussels. Durondean. 4 



" 9. Franeler. Cotte. 



" 10. Holland and Brussels. Cotte. 



" 12. Holland. Cotte. 



Jan. 13. Franeler. Cotte. 



" 14. Saint Saturnin. Cotte. 



« 19. St. Petersburg. Euler. 5 



Feb. 4. Franeler. Cotte. 



1 Mem. Acad. Cienc. Madrid. III. 77. 



2 Jonm. de Phys. XI. 269. and XII. 359. 

 8 Van Swinden suspected auroras on Apr. 27, May 19, 26 



and 28, June 12 and 14, Sept 12 and 18, and Oct. 13 and 17, of 

 this same year. There were twenty-three auroras at Brussels in 

 this year. Mem. de 1'Acad. Brux. III. Table. 



4 Me'm. de l'Acad. Brux. III. Appendix. 



6 Acta. Sci. Acad. Petrop. 1779, Pt. II. p. 414. 



Franeler and Holland. Cotte. 



St. Petersburg. Euler. 



Holland, fyc. Cotte. Brussels. Durondeau. 



Spain. Rico. 1 



Cambridge. Winthrop. Lovering. 



Bordeaux. Cotte. Spain. Rico. 



Berlin. Beguelin. Jena. Zeissing. 



St. Petersburg. Euler. 



Cambridge. Winthrop. Lovering. 



Montmorenci, Holland, fyc. Cotte. 



St. Petersburg. Euler. 



Gurzelen. Spriingli. Wolf. 



Franeler, Holland, ifc. Cotte. 



St. Petersburg. Euler. 



Cambridge. Winthrop. Lovering. 



Berlin. Beguelin. Beziers. Bertholon. 



Holland, fyc. Cotte. St. Petersburg. Euler. 



Gurzelen. Spriingli. Wolf. 



Jena. Zeissing. Vienna. Pilgrara. 



Marseilles, Sfc. Cotte. Jena. Zeissing. 



Montmorenci. Cotte. St. Petersburg. Euler. 



Jena. Zeissing. Spain. Rico. 



Franeler and Copenhagen. Cotte. 



Berlin. Beguelin. Beziers. Bertholon. 



Berlin. Beguelin. 



Nanci. Cotte. 



Dieppe. Cotte. 



St. Petersburg. Euler. 



Franeler. Cotte. 



St. Petersburg. Euler. 



St. Petersburg. Euler. 



St. Petersburg. Euler. 



Nanci, fyc. Cotte. Vienna. Pilgram. 



Spain. Rico. 2 Gurzelen. Spriingli. Wolf. 



St. Petersburg. Euler. 



Franeler and Brussels. Cotte. 



Montmorenci. Cotte. 



Franeler, Holland, SfC. Cotte. 



St. Petersburg. Euler. 



Jena. Zeissing. Brussels. Durondeau. 



Copenhagen and Montmorenci. Cotte. 



Copenhagen. Cotte. 



Nanci. Cotte. 



Franeler. Cotte. 



Cambridge. Winthrop. Lovering. 



Montmorenci. Cotte. 



Brussels. Cotte. St. Petersburg. Euler. 



Acad. Cienc. Madrid. III. 77. 

 Acad. Cienc Madrid. III. 77. 



