44 



OF THE PERIODICITY OF THE AURORA BOREALIS. 



Italy. Beccari. Mairan. 



St. Petersburg. Kraft. 



St. Petersburg. Kraft. 



St. Petersburg. Kraft. 



St. Petersburg. Kraft. 



Lincopice. Sparschuch. 



Lincopim. Sparschuch. 



Plymouth. Huxham. 



Plymouth. Huxham. Lincopice. Sparschuch. 



Plymouth. Huxham. 



Plymouth. Huxham. 



Lincopice. Sparschuch. 



St. Petersburg. Kraft. 



Lincopice. Sparschuch. 



Wittemberg. TTeidler. Mairan. 



St. Petersburg. Kraft. 



Lincopice. Sparschuch. 



Lincopice. Sparschuch. 



Lincopice. Sparschuch. 



Lincopice. Sparschuch. 



Lincopice. Sparschuch. 



Lincopice. Sparschuch. 



Lincopice. Sparschuch. 



1739. 



Lincopice. Sparschuch. 



Lincopice. Sparschuch. 



Mairan and Short. 



Frobes and Mairan. 



Upsal. Celsius. 1 



St. Petersburg. Kraft. 2 



Frobes and Mairan. 



St. Petersburg. Kraft. 



Upsal. Celsius. 



Mairan, Short, and Phil. Trans. 



Frobes and Mairan. 



Upsal. Celsius. St. Petersburg. Kraft. 



Wittemberg. Weidler. Frobes and Mairan. 



Upsal. Celsius. 



Upsal. Celsius. Mairan and Phil. Trans. 



Plymouth. Huxham. Short. 



Mairan and Phil. Trans. 



St. Petersburg. Kraft. 



Bologna. Zanotti and Beccari. 



Frobes and Mairan. 



St. Petersburg. Kraft. 



Plymouth. Huxham. Upsal. Celsius. 



1 Mem. Etrang. Paris, IV. 137. Svenska Vetensk. Acad. I. 

 256. 



2 Comm. Petrop. XI. 255. 



Aug. 13. 



" 19. 

 Sept. 4. 



" 19. 

 Oct. 12. 



" 27. 



" 28. 



Nov. 1. 



4. 



5. 



" 7. 



" 14. 

 Dec. 2. 



" 4. 



" 4. 

 6. 



" 7. 

 9. 



" 10. 



" 15. 



" 17. 



" 19. 



" 27. 



Jan. 2. 



St. Petersburg. Kraft. Mairan. 

 Frobes, Short, and Phil. Trans. 

 St. Petersburg. Kraft. Siberia. Gmelin. 1 

 / r psal Celsius. St. Petersburg. Kraft. 

 St. Petersburg. Kraft. 

 Frobes and Mairan. 

 Plymouth. Huxham. 

 I'jisal. Celsius. 



Bologna. Zanotti and Beccari. Oliva. 2 

 ( 'helsea. Martyn. Phil. Trans. 

 Padua. 3 Poleni. Frobes and Mairan. 

 St. Petersburg. Kraft. Siberia. Gmelin. 

 Upsal. Celsius. Siberia. Gmelin. 

 Upsal. Celsius. 

 Upsal. Celsius. 

 I 'psal. Celsius. 



Philadelphia, Breintnal. Kahn. 

 Plymouth. Huxham. Siberia. Gmelin. 

 Wittemberg. Weidler. Mairan. 

 St. Petersburg. Kraft. 

 / psal. Celsius. 

 I 'psal. Celsius. 

 I'jisul. Celsius. 



Plymouth. Huxham. St. Petersburg. Kraft. 

 Upsal. Celsius 

 Upsal. Celsius. 



Bologna. Zanotti. Matteucci and Mairan. 

 Philadelphia. Breintnal. Kahn. 

 Upsal. Celsius. 

 Upsal. Celsius. 

 Upsal. Celsius. 

 Ipsa!. Celsius. 

 St. Petersburg. Kraft. 

 Upsal. Celsius. 

 St. L'etersburg. Kraft. 

 Upsal. Celsius. 



Upsal Celsius. St. Petersburg. Kraft. 

 I psal. Celsius. 

 I 'psal. Celsius. 

 iSif. Petersburg. Kraft. 



Plymouth. Huxham. Cambridge. Winthrop. 5 

 Philadelphia. Breintnal. Kahn. 

 St. Petersburg. Kraft. 

 Plymouth. Huxham. 

 Mairan, Short, and Phil. Trans. 



1 N. Comm. Petrop. VI. 458. 



2 Comm. Bonon. II. Pt. I. 479. 

 8 Comm. Petrop. VIII. 440. 



1 Comm. Bonon. II. Pt. III. 496. 

 5 Amer. Journ., XL. 206. 



