ON THE PERIODICITY OF THE AURORA BOREALIS. 



127 



May 29. 



" 30. 



" 30. 

 June 1. 



" 10. 



" 22. 



" 25. 



" 26. 



" 28. 

 July 4. 



" 16. 



" 21. 



" 25. 



" 25. 



" 29. 



" 29. 



" 29. 

 Aug. 9. 



" 10. 



" 19. 



" 19. 



" 19. 



" 20. 



" 21. 



" 23. 



" 24. 



" 24. 



" 25. 



" 26. 



" 26. 



" 28. 



" 28. 



" 28. 



" 28. 



" 28. 



" 29. 



" 31. 

 Sept. 1. 



" 2. 



" 19. 



" 21. 



" 21. 



" 21. 



" 21. 



" 21. 



" 22. 



" 23. 



Toronto. Sabine. Paris. Bouvard. 1 

 New Haven. Herrick. Newtoi. and Loomis 



Hough. Canada. Riddcll. 

 Bond. Lovering. 



Hough. 



Bond. Lovering. 



Hough. 

 Lovering. 



Hough. 

 Lovering 



1 Mem. Amer. Acad. II. 52. 



2 Amer. Journ. Sci. XXXIX 194 and 383. XL. 337. 



New York. Plough. 



New York. 



Cambridge. 



New York. 



Cambridge. 



New York. 



Cambridge. 



New York. 



Cambridge. 



New Haven. Herrick. Newton and Loomis. 



Toronto. Sabine. 



New Haven. Herrick. Newton and Loomis. 



New York. Hough. 



Cambridge. Lovering. Bond. 



New Haven. Herrick. Newton and Loomis. 



Providence, R. I. Caswell. New York. Hough. 



New York. Hough. 



Hough. 

 Lovering. 

 Herrick. Newton and Loomis. 



Hough. Toronto. Sabine. 



Hough. 

 Hough. 

 Hough. 

 Herrick. Newton and Loomis. 



Gilliss. 



New York. 

 Cambridge. 

 New Haven. 

 New York. 

 New York. 

 New York. 

 New York. 

 New Haven. 

 Toronto. Sabine. 

 New York. Hough. 

 New York. Hough. 

 Christiania. Hansteen. 

 Cambridge. Lovering. Washington. 

 Boston. Hale. Lovering. 

 New Haven. Herrick. Newton and Loomis. 

 New York. Hough. Toronto. Sabine. 2 

 Hansteen. 

 Herrick. Newton and Loomis. 



Bond. Lovering. 



Hough. Newberry. Johnson. 

 Toronto. Sabine. 

 New Haven. Herrick. Newton and Loomis. 



Bond. Lovering. 

 Herrick. Newton and Loomis. 



Hough. Washington. Gilliss. 

 Toronto. Sabine. Paris. Bouvard. 

 Christiania. Hansteen. Brussels. Quetelet. 

 New Haven. Herrick. Newton and Loomis. 

 New York. Hough. Washington. Gilliss. 



Christiania. 

 New Haven. 

 Cambridge. 

 New York. 



Cambridge. 

 New Haven. 

 New York. 



1 Connaiss. de Terns. 1844, p. 408. 



2 Compt. Rend. XIU. 724-5. 



