154 



ON THE PERIODICITY OF THE AURORA BOREALIS. 



May 26. Kingston. Lefroy. 



" 27. Montreal. Lefroy. 



June 5. Dorpat. Miidler. Jahn. 



" C. Quebec. Lefroy. 



" 8. Kingston. Lefroy. 



" 10. New York. Hough. 



" 12. Neio Haven. Herrick. Newton and Loomis. 



" 14. New York. Hough. Quebec. Lefroy. 



" 1 6. Quebec ? Lefroy. 



" 17. New York. Hough. Montreal. Lefroy. 



" 18. Montreal. Lefroy. 



" 19. New York. Hough. 



" 20. Toronto and London. Lefroy. 



" 20. Newfoundland and Quebec. Lefroy. 



" 22. Toronto. Lefroy. 



" 24. Kingston and London. Lefroy. 



" 25. Halifax? Lefroy. 



" 26. Warren Centre, Connecticut. Hough. 



" 27. Quebec. Lefroy. 



" 29. New York. Hough. 



July 3. Halifax. Lefroy. 



" 4. Halifax. Lefroy. 



" 5. Toronto. Lefroy. 



" 9. New York. Hough. 



" 9. Newfoundland and Toronto. Lefroy. 



" 10. Toronto. Lefroy. 



" 12. New Haven. Herrick. Newton and Loomis. 



" 12. New York. Hough. London, C. W. Lefroy. 



" 13. Cambridge. Bond. Lovering. 



" 14. New York. Hough. 



" 20. Toronto. Lefroy. 



" 21. Newfoundland. Lefroy. 



" 22. New York. Hough. 



" 22. Quebec and Toronto. Lefroy. 



" 23. New Haven. Herrick. Newton and Loomis. 



" 23. New York. Hough. 



" 23. Montreal, Kingston, and Toronto. Lefroy. 



" 23. Newfoundland and Quebec. Lefroy. 



" 23. Halifax and London, C. W. Lefroy. 



" 24. New York. Hough. 



" 26. Toronto. Lefroy. 



" 31. Montreal and Quebec. Lefroy. 



" 31. Kingston, Toronto, and London. Lefroy. 



" 31. Newfoundland. Lefroy. 



" 31. Christiania. Hansteen. 



Aug. 2. Toronto. Lefroy. 



" 4. Newfoundland and Kingston. Lefroy. 



" 12. New York. Hough. 



" 12. Fenelon Falls and London. Lefroy. 



" 12. Newfoundland and Toronto. Lefroy. 



New York. Hough. 



Middlebury, Yt. Herrick. Newton and Loomis. 



Kingston and Newfoundland. Lefroy. 



Montreal. McGinn. Lefroy. 1 



New York. Hough. 



New York. Hough. 



Toronto and London. Lefroy. 



Newfoundland. Lefroy. 



Kingston and Toronto. Lefroy. 



Halifax and Quebec. Lefroy. 



New York. Hough. 



New York. Hough. 



Quebec. Lefroy. 



New York. Hough. Christiania. Hansteen. 



Fort Macpherson. Hooper. 



New Haven. Herrick. Newton and Loomis. 



New York. Hough. 



Newfoundland and Toronto. Lefroy. 



Fort Macpherson. Hooper. 



New York. Hough. Newberry. Johnson. 



Kingston, Toronto, and London. Lefroy. 



New Haven. Herrick. Newton and Loomis. 



New York. Hough. Montreal. Lefroy. 



New York. Hough. Providence. Caswell. 



Pittsfield. Herrick. Newton and Loomis. 



Near Portland.Herrick. Newton and Loomis. 



Newfoundland and Kingston. Lefroy. 



Halifax and Toronto. Lefroy. 



Fort Macpherson. Hooper. Sitka. KupfFer. a 



New York. Hough. 



New Haven. Herrick. Newton and Loomis. 



New York. Hough. 



Newfoundland and Montreal. Lefroy. 



Fort Macpherson. Hooper. 



New York. Hough. 



Fenelon Falls and Toronto. Lefroy. 



Fort Macpherson. Hooper. 



Makersioun. Broun. 



Worcester. Chandler. Newberry. Johnson. 



Providence. Caswell. New York. 'Hough. 



New Haven. Herrick. Newton and Loomis. 



Montreal, Kingston, and Toronto. Lefroy. 



Halifax and Fenelon Falls. Lefroy. 



Newfoundland and Quebec. Lefroy. 



Makerstoun. Broun. 



New York. Hough. 



Quebec and Montreal. Lefroy. 



i Phil. Mag. Third Series, XXXVX 545. 



2 Annal. de l'Observ. Phys. Centrale de Russie, 1849, p. 377. 



