38 



ON THE PERIODICITY OF THE AURORA BOREALIS. 



Mar. 26. Paris ? Mairan. Frobes. 



27. Sweden. Celsius. Frobes and Mairan. 

 •' 28. St. Petersburg. The Delisles. 



" 28. Berlin. Kirch. Paris ? Mairan. 



28. Sweden. Celsius. Frobes. 



" 29. St. Petersburg. The Delisles. 



" 29. Sweden. Celsius. Frobes and Mairan. 



" 31. St. Petersburg. The Delisles. 



" 31. Sweden. Celsius. Frobes and Mairan. 



Apr. 1. St. Petersburg. The Delisles. Celsius. Mairan. 



" 2. Sweden. Celsius. Frobes and Mairan. 



3. St. Petersburg. The Delisles. Paris. Mairan. 



" 4. St. Petersburg. The Delisles. Mairan. 



" 16. Paris. Mairan. 



" 17. Paris. Mairan. Sweden. Celsius. Frobes. 



18. Sweden. Celsius. Paris. Mairan. Frobes 



" 19. Sweden. Celsius. Frobes and Mairan. 



20. Sweden. Celsius. Frobes and Mairan. 



" 22. Sweden. Celsius. Frobes and Mairan. 



" 24. Berlin. Kirch. Mairan and Phil. Trans. 



" 25. Paris. Mairan. 



" 26. Paris. Mairan. 



" 27. Paris. Mairan. 



May 14. Paris. Mairan. 



" 20. Paris. Mairan. 



" 23. Paris. Mairan. 



June 25. Frobes and Mairan. 



" 26. Paris. Mairan. Frobes. 



July 12. Paris. Mairan. 



•' 21. Italy. Beccari. Mairan. 



" 27. St. Petersburg. The Delisles. Mairan. 



Aug. 19. Meudon. Mairan. 



" 22. Witlemberg. Weidler. Berlin. Kirch. 



" 22. Sweden. Celsius. Phil. Trans. 



" 22. Paris. Mairan. Frobes. 



" 23. Celsius, Frobes, and Mairan. 



" 27. St. Petersburg. Kraft. 



" 30. Paris. Du Fay. Mairan. 



Sept. 1. St. Petersburg. The Delisles. 



" 1. Paris. Buache. Mairan and Thompson. 



" 5. Paris. Mairan. 



" 10. Berlin. Kirch. Breuillepont. Mairan. 



" 10. Frobes and Phil. Trans. 



" 11. Breuillepont. Mairan. 



" 18. St. Petersburg. Kraft. The Delisles. Mairan. 



" 18. Italy. Veratti. 1 



" 19. St. Petersburg. The Delisles. 



" 19. Breuillepont. Mairan. Frobes. 



« 20. St. Petersburg. The Delisles. 



» Comm. Bonon II. Pt. III. 493. 



Breuillepont. Mairan. Frobes. 

 St. Petersburg. Kraft. Breuillepont. Mairan. 

 Frobes and Mairan. 

 Frobes and Mairan. 

 Frobes and Mairan. 

 St. Petersburg. The Delisles. 

 Paris. Mairan. Frobes. 

 St. Petersburg. The Delisles. 

 Berlin. Kirch. Mairan. 

 St. Petersburg. The Delisles. Mairan. 

 Paris. Mairan. 

 Paris. Mairan. 

 Paris. Mairan. 

 St. Petersburg. The Delisles. 

 Berlin. Kirch. Paris. Mairan 

 Sweden. Celsius. Frobes. 

 Paris. Mairan. 



St. Petersburg. The Delisles. Mairan. 

 St. Petersburg. The Delisles. Mairan. 

 Paris. Mairan. 

 Paris. Mairan. Frobes. 

 Paris. Mairan. 

 Paris. Mairan. 



St. Petersburg. The Delisles. Paris. Mairan 

 St. Petersburg. The Delisles. Mairan. 

 Paris. Mairan. 



Berlin. Kirch. Paris. Mairan. 

 Sweden. Celsius. Frobes. 

 Wittemberg. Weidler. Paris. Mairan. 

 Berlin. Kirch. Phil. Trans. 

 Sweden. Celsius. Frobes. 

 Paris. Mairan. 



St. Petersburg. The Delisles. Paris. Mairan, 

 St. Petersburg. The Delisles. Paris'! Mairan. 

 St. Petersburg. The Delisles. Mairan. 

 St. Petersburg. The Delisles. Mairan. 

 St. Petersburg. The Delisles. Paris. Mairan. 

 Paris. Mairan. 



St. Petersburg. Kraft. The Delisles. 

 Paris. Mairan. 

 Sweden. Celsius. Mairan. 

 St. Petersburg. The Delisles. 

 Berlin. Kirch. Frobes and Thompson. 

 Copenhagen. Horrebow. Mairan. 

 St. Petersburg. The Delisles. Frobes. Mairan. 

 St. Petersburg. Kraft. The Delisles. Mairan. 

 St. Petersburg. The Delisles. Mairan. 

 St. Petersburg. Kraft. The Delisles. Mairan. 

 Italy. Beccari. Frobes and Mairan. 

 St. Petersburg. The Delisles. Mairan. 



