ON THE PERIODICITY OF THE AURORA BOREALIS. 



21 



1571. Mar, 



1572. 



1573. 



1574. 



1575. 



1577. 



1580. 



14. 



30. 



22. 



27. 



11. 



12. 

 " 13. 

 " 14. 

 April 26. 



Jan. 

 Jan. 

 Mar. 



Jan. 

 Feb. 



April 



1. 



6. 

 16. 

 23. 



9. 

 9. 

 " 21. 

 Nov. 28. 

 Jan. x. 

 Aug. 30. 

 Nov. 24. 

 " 24. 

 " 25. 

 " 25. 

 28. 

 23. 

 " 23. 

 " Oct. 8. 

 " " 8. 



" 8. 

 1. 

 2. 

 27. 

 4. 

 4. 

 " 15. 

 " 16. 

 " 17. 

 " 18. 

 Dec. 28. 



Dec. 



Feb. 



1576. Jan. 



" Feb. 



" June 



" Dec. 



Mar. 16. 



" 16. 

 April 16. 



" 16. 



" 19. 



" 19. 



Kirch, Mairan, 1 and Acad. Coll. 



Pilgram. 



Kirch, RJairan, and Acad. Coll. 



Zurich. Wolf. 



Kirch and Mairan. 



Kirch, Mairan, and Acad. Coll. 



Kirch, Mairan, Pilgram, Acad. Coll. 

 Kirch, Mairan, and Acad. Coll. 



Constantinople. Frobes, M'n., A. C. 



Befort. Berk, Frobes, and Mairan. 2 



Gemma, Mairan, and Pilgram. 



Zurich.? Wolf. 



Zurich.? Wolf. 



France. Scheuchzer. 



Frobes, Mairan, and Acad. Coll. 



Kirch, Mairan, and Acad. Coll. 



Liejiand, Russia. Frobes, M'n., A. 



Gemma, Mairan, and Pilgram. 



Zurich. Wolf. 



England. Camden, 8 Stow. 



Frobes, Mairan, and Acad, Coll. 



England. Camden, Stow, 4 Kirch. 



Frobes, Mairan, and Acad. Coll. 



Zurich. Wolf. 



Brabant. Gemma, Frobes, Mairan. 



Pilgram, Acad. Coll. Thompson. 



Zurich. Wolf. Gemma. 



Gemma, Frobes, and Thompson. 



Kirch, Mairan, 6 and Acad. Coll. 



Zurich. Wolf. 

 Zurich. Wolf. 

 Zurich. Wolf. 

 Zurich. Wolf. 

 Zurich. Wolf. 

 Zurich. Wolf. 

 Zurich. Wolf. 

 Zurich. Wolf. 

 Zurich. Wolf. 



Kirch, Mairan, Moestlin, 6 Acad. Coll. 

 Baknang, Wurtemberg. Moestlin, F's. 

 Mairan, Pilgram, and Acad. Coll. 

 Wurtemberg. Moestlin, Frobes, M'n. 

 Halley, Pilgram, and Acad. Coll. 

 Wurtemberg. Moestlin, Frobes, M'n. 

 Halley, Pilgram, and Acad. Coll. 



1 This is given erroneously by Mairan as March 15. 



- Scheuchzer. Biblioth. Scrip. Hist. Nat. p. 75. 



8 Rerura Anglicarnm et Hybernicarum Annates, p. 263. 



4 A General Chronicle of England, p. 678. 



6 Mairan quotes this aurora from Frobes, as upon Sept. 28. 



G Consideratio et Observatio comette aetherei, &c. 



1580. Sept. 5. 



Botle. 



Wurtemberg. Moestlin, Frobes, M'n. 

 Halley, Kirch, Pilgram, Acad. Coll. 

 Wurtemberg. Moestlin, Frobes, M'n. 

 Halley, Pilgram, and Acad. Coll. 

 Kirch and Mairan. 

 Zurich. Wolf. 



Halley, Mairan, Moestlin, Pilgram. 

 Wurtemberg. Moestlin, Frobes, M'n. 

 Halley, Pilgram, and Acad. Coll. 

 Germany. Frobes, Kirch, Mairan. 

 Wurtemberg. Moestlin, Frobes, M'n. 

 Halley, Pilgram, and Acad. Coll. 

 Kirch, Mairan, and Acad. Coll. 

 Brabant. Frobes, Mairan, Acad. C. 

 Zurich. Wolf, Kirch, Mairan, Acad. 

 Kirch, Mairan, and Acad. Coll. 

 Zurich. Wolf. 



Kirch, Mairan, and Acad. Coll. 

 Kirch, Mairan, and Acad. Coll. 

 Zurich. Wolf. Meissen. Lehmann. 

 Frobes, Kirch, Mairan, Acad. Coll. 

 Kirch, Mairan, and Acad. Coll. 

 Prussia. Hennenberger. 1 

 Frobes, Kirch, Mairan, Acad. Coll. 

 Zurich. Wolf, Kirch, Mairan, Acad. 

 Kirch and Mairan. 

 Zurich. Wolf. 



Kirch, Mairan and Acad. Coll. 

 Zurich. Wolf. 



Zurich. Wolf, Kirch, Mairan, A. C. 

 Kirch, Mairan and Acad. Coll. 

 Zurich. Wolf. 



Kirch, Mairan, and Acad. Coll. 

 Kirch, Mairan, and Acad. Coll. 

 Kirch, Mairan, and Acad. Coll. 

 Brandenberg. Frobes. 2 

 Kirch, Mairan, and Acad. Coll. 

 Upsal. Celsius, Frobes, M'n., A. C. 

 Hondorff, Frobes, Mairan, A. C. 

 Hondorff, Frobes, Mairan, A. C. 

 Hondorff, Frobes, Mairan, A. C. 

 Kirch, Mairan, and Acad. Coll. 

 Kirch, Mairan, and Acad. Coll. 

 Berne. Wolf. 

 Zurich. Wolf. 



Kirch, Mairan, and Acad. Coll. 

 Kirch, Mairan, and Acad. Coll. 



1 Erklarung der Land-Tafel von Prcussen. 



2 Hondorfli Calendarium Sanctorum, &c, p. 102. 



