92 



ON THE PERIODICITY OF THE AURORA BOREALIS. 



Moscow. Stritter. 



Kendal. Dalton. 



Peissenberg. Schwaiger. Sagan. Preus. 



Salem. Holyoke. Lovering. 



Jlnissels. Mann. 



Cambridge. Wigglesworth. Lovering. 



Salem. Holyoke. Lovering. 



Kendal. Dalton. 



Stockholm. Nicander. 



St. Petersburg. Euler. 



Kendal. Dalton. 



Kendal. Dalton. 



Stockholm. Nicander. 



Kendal. Dalton. 



Peissenberg. Schwaiger. 



Stockholm. Nicander. 



Kendal. Dalton. 



Stockholm. Nicander. 



Cambridge. Wigglesworth. Lovering. 



Salem. Holyoke. Lovering. 



Hingham, Mass. Ware. 



Stockholm. Nicander. St. Petersburg. Euler. 



Kendal. Dalton. Cuba. Poey. 



Beziers. Betholon. 1 Sagan. Preus. 



Pome. Calandrelli. Stockholm. Nicander. 



Stockholm. Nicander. 



Brussels. Mann. 



Sagan. Preus. Kendal. Dalton. 



Sagan. Preus. 



St. Petersburg. Euler. 



Stockholm. Nicander. Kendal. Dalton. 



Stockholm. Nicander. 



Sagan. Preus. Kendal. Dalton. 



Kendal. Dalton. 



Stockholm. Nicander. 



Stockholm. Nicander. 



Stockholm. Nicander. 



St. Petersburg. Euler. 



Montmorenci. Cotte. 



Sagan. Preus. 



Salem. Holyoke. Lovering. 



Salem. Holyoke. Lovering. 



Sagan ? Preus. Kendal. Dalton, 



Sagan ? Preus. 



Sagan ? Preus. 



( 'ambridge. Wigglesworth. 



Sagan ? Preus. 



Peissenberg. Schwaiger. • 



Stockholm. Nicander. 



Mannheim. Hemmer. Sagan 1 ? Preus. 



Eneyc. Method. I. 368. 



Kendal. 

 Kendal. 



Kendal. 



Dalton. 

 Dalton. 

 Dalton. 



Lovering. 



Dec. 23. 



" 24. 

 " 26. 

 " 27. 



Jan. 2. 



" 9. 



" 10. 



" 14. 



" 15. 



« 18. 



" 19. 



" 26. 



" 28. 



" 29. 



" 29. 

 Feb. 1. 



9. 



" 10. 



" 11. 



" 11. 



" 12. 



" 12. 



" 13. 



" 14. 



" 15. 



" 18. 



" 27. 

 Mar. 3. 



" 7. 



" 8. 



" 8. 



" 10. 



" 11. 



" 14. 



" 15. 



" 16. 



" 16. 



" 17. 



" 17. 



" 18. 



" 18. 



" 19. 



" 20. 



" 23. 



" 24. 



Stockholm. Nicander. 



New Haven. Stiles. Loomis. Paris. Cassini. 



Stockholm. Nicander. 



Stockholm. Nicander. 



1790. 



Stockholm. Nicander. 

 Sagan. Preus. 

 Sagan. Preus. 

 Stockholm. Nicander. 

 Stockholm. 

 Mannheim. 

 Stockholm. 

 Stockholm. 



Kendal. Dalton. 



Nicander. 



Hemmer. Sagan. Preus. 



Nicander. 



Nicander. 

 Laon. Cotte. 



Mannheim. Hemmer. Sagan. Preus. 

 Jena. Zeissing. Prague. Strnad. 

 Sagan. Preus. 

 Kendal. Dalton. 

 Stockholm. Nicander. 

 Stockholm. Nicander. Kendal. Dalton. 

 Stockholm. Nicander. 

 Salem. Holyoke. Lovering. 

 Stockholm. Nicander. 

 Sagan. Preus. Stockholm. Nicander. 

 Salem. Holyoke. Lovering. 

 Sagan. Preus. Stockholm. Nicander. 

 Mannheim. Hemmer. Stockholm. Nicander. 

 Sagan. Preus. 



Stockholm. Nicander. Brussels. Mann. 

 Stockholm. Nicander. 

 Mannheim. Hemmer. 

 Stockholm. Nicander. 

 Peissenberg. Schwaiger. 

 Stockholm. Nicander. Brussels. Mann. 

 Stockholm. Nicander. Kendal. Dalton. 

 Stockholm. Nicander. Sagan. Preus. 

 Stockholm. Nicander. 

 Stockholm. Nicander. 

 Kendal. Dalton. Sagan. Preus. 

 Stockholm. Nicander. Ratisbon. Heinrich. 

 Sagan. Preus. Kendal. Dalton. 

 Stockholm. Nicander. 

 Mannheim. Hemmer. Kendal. Dalton. 

 Stockholm. Nicander. 

 Stockholm. Nicander. Kendal. Dalton. 

 Stockholm. Nicander. Kendal. Dalton. 

 Stockholm. Nicander. 

 Stockholm. Nicander. 



