258 



ON THE PERIODICITY OF THE AURORA BOREALIS. 



♦July 7. Toronto. Sabine. Wolf. 



Sept. 6. Bogoslowski. Kupffer. 1 



* " 27. Sitka. Kupffer. 

 *Oct. 15. Sitka. Kupffer. 



* " 19. Sitka. Kupffer. 

 Dec. 10. New Haven? Wolf. 2 



♦March 7. 



" 28. 



*April 16. 



« 24. 



June 20.' 



*Sept. 13. 



" 24. 



" 26. 



21. 



6. 



15. 



16. 



Dec. 13. 



*Oct. 



♦Nov 



* u 



* a 



May 4. 



" 15. 



" 30. 



Aug. 25. 



*Jan. 16. 



June 16. 



July 21. 



" 28. 



*Aug. 27. 



♦Sept. 11. 



22. 



24. 



25. 



12. 



15. 



19. 



17. 



# « 



# a 



# n 



♦Oct. 



# u 



# u 

 *Nov. 



Dec. 12. 



1844. 



Sitka. Kupffer. 



Sitka. Kupffer. 



Sitka. Kupffer. 



New Haven ? Wolf. 3 



Toronto. Sabine. Wolf. 



Hclsinrjfnrs. Nervander. Wolf. 4 



Sitka. Kupffer. 



Sitka. Kupffer, 



Sitka. Kupffer. 



Baltisch} tort. Kupffer. 



Sitka. Kupffer. 



Baltischport. Kupffer. 



Toronto. Sabine. Wolf. 



1845. 

 Helsingfors. Nervander 

 Helsingfors. Nervander. 

 Helsingfors. Nervander. 

 Wolf. 5 



1846. 



Baltischport. 



Baltischport. 



Helsingfors. 



Helshigfors. 



Baltischport. 



BaltischpoH. 



Baltischport. 



Baltischport. 



Baltischport. 



Helsingfors. 



Helsingfors. 



Baltischport. 



Baltischport. 



Helsingfors. 



Kupffer. 

 Kupffer. 

 Nervander. 

 Nervander. 

 Kupffer. 

 Kupffer. 

 Kupffer. 

 Kupffer. 

 Kupffer. 

 Nervander. 

 Nervander. 

 Kupffer. 

 Kupffer. 

 Nervander. 



1 Annuaire Magnet, et Meteor, de Russie,' 1843, p. 425. 



2 Bull, de l'Acad. Brux. XII. 533. 

 5 Bull, de l'Acad. Brux. XII. 534. 

 4 Observ. faites & Helsingfors. 



* Bull, de l'Acad. Brux. XII. 



Feb. 11. 



♦March 19. 



" 20. 



" 23. 



" 26. 



7. 



20. 



10. 



24. 



31. 



♦April 



# « 



Oct. 



# » 



* u 

 ♦Dec. 17. 



♦ " 29 



Feb. 



9. 

 ; " 20. 



* " 22. 



* " 24. 

 March 15. 



* " 19. 



* " 20. 



* " 20. 

 " 28. 



* " 29. 

 31. 



3. 



# « 

 ♦April 



♦ " v. 



♦ " 17. 



♦ " 29. 

 July 8. 



♦ " 11. 



♦ " 24. 

 ♦Sept. 4. 



♦ " 5. 

 " 7. 

 " 23. 



♦ " 30. 

 Oct. 11. 



♦ " 17. 



1847. 

 Helsingfors. Nervander. 

 Baltishport. Kupffer. 

 Helsingfors. Nervander. 

 Helsingfors. Nervander. 

 Gainsborough. Thompson. 1 

 Hartford. Conn. Wolf. 2 

 Helsingfors. Nervander. 



Helsingfors. 

 Baltischport 

 Christiania, 

 Baltischport. 

 Il( Isingfors. 



Nervander. 



Kupffer 

 Wolf. 3 



Kupffer. 

 Nervander. 



1848. 



Helsingfors. Nervander. Wolf. 



Greenwich. Glaisher. Durham.* 



Greenwich. Glaisher. Stone. 



At Sea, Lt. 53° 41' N. Lg. 16° 25' W. b 



Stonyh urst. Glaisher. 



Greemvich. Glaisher. Durham. Scarva. 



Greenwich. Glaisher. 



Durham. Stonyhurst. 



Leeds. Glaisher. 



Hurt wick, U. S. Glaisher. 



Greenwich. Glaisher. Stonyhurst. 



!/'/■<< ii a- id/ . Glaisher. 



Greemvich. Glaisher. 



Stone. Lefroy. 6 



Greenwich. Glaisher. 



V ip Creole, Lt. 52° 12 N. Lg. 6° 12' W. 



Sli ip Ash Icy, Lt. 46° 16' N. Lg. 34° 6' E. 



Banna. Colla. Wolf! 7 



Ship Liverpool, Lt. 42° 36' N. Lg. 50° W. 



Ship Liverpool, Lt. 43° 38' N. Lg. 46° TV. 



Frunconifi, New Hampshire. 



Ship Ohio, Lt. 51° 16' N. Lg. 10° W. 



Aix-la- Chapelle. Heis. 8 



Fart. Confidence ? Eichardson. 



Stonyhurst. Lefroy. 



1 Introduction to Meteorology, p. 355. 



2 Fortschritte der Physik. Jahrgang III. 179. 



3 Bull, de l'Acad. Brux. XXI. 289. 



4 Return of the Mortality in 117 Districts of England, VII., 

 No. 1, p. 10 ; No. 2, p. 17 ; No. 4, p. 20. 



■ ! Manuscript Records of the Smithsonian Institution. 

 s From his Manuscript Records. 



7 Bull, de l'Acad. Brux. XVI. 6. 



8 Bull, de l'Acad. Brux. XVI. 4. (Zodiacal Light ?) 



