OF THE PERIODICITY OF THE AURORA BOREALIS. 



Feb. 23? Upsal. Bergman. 



" 24. Upsal. Bergman. 



" 25 ? Upsal. Bergman. 



" 26. Upsal. Bergman. St. Petersburg. Braun. 1 



" 27. Hernosand. Gisler. Boue. Thompson. 



" 27. Upsal. Bergman. <Sif. Petersburg. Braun. 



" 28. Hungary. Weiss. Reuss. a 



" 28. Upsal. Bergman. St. Petersburg. Braun. 



Mar. 1. Upsal. Bergman. 



" 5. Upsal. Bergman. 



" 10. Cambridge. Wintbrop. Lovering. 



" 11. Cambridge. Wintbrop. Lovering. 



" 15. Upsal. Bergman. 



" 26. Upsal. Bergman. 



Apr. 3. Upsal. Bergman. 



" 4. Upsal. Bergman. 



" 5. Upsal. Bergman. 



" 6. Upsal. Bergman. 



" 7. Upsal. Bergman. 



" 8. Upsal. Bergman. 



" 12. Upsal. Bergman. 



" 13. Upsal. Bergman. 



May 2. Upsal. Bergman. 



Aug. 1. Greenland. Crantz. 8 Force. 



" 11. Marienstadt. Bergman. 



" 21. Greenland. Crantz. Force. 



" 27. Marienstadt. Bergman. 



" 29. St. Petersburg. Braun. 



" 30. Marienstadt. Bergman. 



Sept. 9. St. Petersburg. Braun. 



" 10. St. Petersburg. Braun. 



" 24. Marienstadt. Bergman. 



" 25. Hernosand. Gisler. Boue. 



" 25. St. Petersburg. Braun. 



" 25. Marienstadt. Bergman. 



" 25. Hernosand. Gisler. Boud and Thompson. 



" 26. Cambridge. Wintbrop. Lovering. 



" 26. Marienstadt. Bergman. 



" 26. St. Petersburg. Braun. 



" 27. Marienstadt. Bergman. 



" 28. Marienstadt. Bergman. 



Oct. 22. Marienstadt. Bergman. 



" 22. St. Petersburg. Braun. 



" 23. Marienstadt. Bergman. 



" 31. St. Petersburg. Braun. 



Nov. 6. Cambridge. Wintbrop. Lovering. 



1 N. Comm. Tetrop. XL 320. 



2 Mem. de l'Acad. 1761, p. 25. 



8 Hist, of Greenland. Also, Record of Auroral Phenomena, 

 by P. Force. Smith. Contrib. VIII. 22, I. 48. 



