34 



ON THE PERIODICITY OF THE AURORA BOREALIS. 



May. 29. 

 " 81. 



June 15. 



« 26. 

 July 7. 

 Aug. 29. 

 Sept. 10. 



" 12. 



" 15. 



" 15. 



" 20. 



« 21. 



" 22. 



" 22. 



" 22. 



« 23. 



" 26. 

 Oct. 2. 



" 11. 



" 13. 



'• 13. 



" 17. 



" 21. 



" 22. 



" 22. 



" 24. 



" 25. 



" 25. 

 Nov. 16. 



« 16. 



" 16. 



" 16. 



" 17. 



" 18. 



" 19. 



« 20. 



" 30. 

 Dec. 17. 



« 22. 



" 27. 



" 30. 



Paris ? Mairan. Pilgram. 



Frobes and Mairan. 



Paris ? Mairan. Frobes. 



Paris ? Mairan. Frobes. 



Berlin. Kirch. Mairan. 



St. Petersburg. The Delisles. Mairan. 



St. Petersburg. Kraft. The Delisles. Mairan. 



Sweden. Celsius. Frobes and Mairan. 



Oustiong. Croyere. Sioeden. Celsius. 1 



Paris. Mairan. Frobes. 



Frobes, Mairan, and Pilgram. 



St. Petersburg. Kraft. The Delisles. Mairan. 



St. Petersburg. Kraft. The Delisles. 



Paris. Mairan. Pilgram. 



Sweden. Celsius. Frobes. 



Plymouth. Huxham. Mairan and Short. 



Berlin. Kirch. Mairan. 



Sweden. Celsius. Mairan. 



Frobes and Mairan. 



Berlin. Kirch. Sweden. Celsius. 



Paris. Mairan. Frobes and Pilgram. 



Frobes and Mairan. 



Phil. Trans. Mairan. 



Berlin. Kirch. Mairan. 



Sweden. Celsius. Frobes. 



Sweden. Celsius. Frobes and Mairan. 



Plymouth. Huxham. Short. 



Paris. Cassini. Mairan. 2 



St. Petersburg. Kraft. The Delisles. 



Plymouth. Huxham. Phil. Trans. 



Berlin. Kirch. Paris. Mairan. Pilgram. 



Celsius. Frobes and Short. 



Celsius. Frobes and Mairan. 



Celsius. Frobes and Mairan. 



Celsius. Frobes and Mairan. 



Celsius. Frobes and Mairan. 



Celsius. Frobes and Mairan. 

 Kirch. Frobes and Mairan. 



Sweden. 



Sweden. 



Sweden. 



Sweden. 



Sweden. 



Sweden. 



Berlin. 



Sweden. 



Sweden. 



Sioeden. 



Celsius. 

 Celsius. 

 Celsius. 



1730. 



Frobes and Mairan. 

 Frobes and Mairan. 

 Frobes and Mairan. 



Jan. 8. Wittemberg. Weidler. Mairan. 



" 8. Sweden. Celsius. Frobes. 



" 9. Mairan, Pilgram, and Phil.Trans. 



" 16. St. Petersburg. Kraft. The Delisles. 



1 Acta Lit. Sueeite, II. 611. 



2 Me"m. de l'Acad. 1729, p. 321. 



Sweden. Celsius. 



Sweden. Celsius. 



Sweden. Celsius. 



Sweden. Celsius. 



Frobes and Mairan. 

 Frobes and Mairan. 

 Frobes and Mairan. 

 Frobes and Mairan. 



Paris. Mairan. Pilgram. 



Frobes and Mairan. 



Sweden. Celsius. Frobes and Mairan. 



Sweden. Celsius. Frobes and Mairan. 



St. Petersburg. Kraft. The Delisles. Mairan. 



Geneva. Cramer. 1 Italy. Beccari. 



Sweden. Celsius. 2 Frobes and Pilgram. 



Berlin. Kirch. Mairan. 



Betw'n Schleusselb'g S; St. Petersb'g. Croyere. 



Sweden. Celsius. Frobes. 



Frobes and Mairan. 



Sweden. Celsius. Frobes and Mairan. 



Berlin. Kirch. Mairan. 



Sweden. Celsius. Frobes. 



Italy. Beccari. Mairan. 



St. Petersburg. Kraft. The Delisles. 



Plymouth. Huxham. Abo. Sporing. 8 



Paris. Bouillet. 4 Italy. Beccari. 



Celsius, Frobes, Mairan, and Pilgram. 



Short and Phil. Trans. 



Sweden. Celsius. Frobes and Mairan. 



St. Petersburg. Kraft. The Delisles. Mairan. 



Bologna. Zanotti. 6 Mairan. 



St. Petersburg. Kraft. The Delisles. Mairan. 



Bologna. Zanotti and Beccari. 



St. Petersburg. Kraft. The Delisles. Mairan. 



Abo. Sporing. Celsius and Frobes. 



St. Petersburg. Kraft. The Delisles. 



Mairan and Thompson. 



Frobes and Mairan. 



St. Petersburg. Kraft. The Delisles. 



Bologna. Zanotti. Frobes and Mairan. 



Plymouth. Huxham. Mairan and Short. 



Bologna. Zanotti. Mairan. 



Sweden. Celsius. Frobes. 



Abo. Sporing. Mairan. 



Boue and Mairan. 6 



Phil. Trans. Mairan. 



St. Petersburg. Kraft. The Delisles. Mairan. 



1 Phil. Trans. XXXVI. 279. 



2 Acta Lit. Sueciae, HI. A. 106. 

 8 Acta Lit. Sneciffi, III. A. 109. 

 1 Mem. de l'Acad. 1730. 



6 Comm. Bonon. II. Pt. III. 489. 

 6 Not in any special catalogue. 



