218 ON THE PERIODICITY OF THE AURORA BOREALIS. 



Quetelet 1 Las given careful attention to the inquiry, whether any relation exists be- 

 tween the periodicity of the aurora and of shooting stars. He draws attention to the 

 fact that while Mairan rejected the idea of any relationship between the two classes of 

 phenomena, because he supposed auroras to be cosmical and shooting stars terrestrial 

 in their origin, at the present day the shooting stars are believed to be of a planetary 

 character and the aurora to be comparatively near to the earth's surface. Quetelet ad- 

 mits tbat the periodicity of auroras conforms to the recurrence of the seasons, and 

 exhibits nearly the same periods of maxima and minima now as formerly, whereas the 

 periodicity of the shooting stars stands in a less definite relation to the seasons, and the 

 November period of maxima appears to have come in ancient times as early as the last 

 days of October, and the August period between July 25 and 30. He rests his argument 

 in favor of some affiliation between phenomena apparently disconnected on the fact that, 

 out of twenty-eight unusual exhibitions of shooting stars since 1830, fifteen have been 

 accompanied or preceded by auroras; viz., December 7 and 12, 1830; August 10 

 1831; November 13 1832; December 12, 1833; August 12, 1834; August 10 and 

 November 15,1836; November 15,1837; October 18, November 13, and December 

 7,1838; January 2,1839; January 2,1840; and August 11, 1841. Moreover, on 

 August 15, 1830, and on November 12 and 14, 1839, when the expected display of 

 shooting stars nearly failed, its place seemed to have been taken by an exhibition of 

 aurora. Quetelet arrives at the following judicious conclusion: — 



" Ces rapprochements ne prouvent sans doute pas que les etoiles nlantds et les aurores boreales doivent etre rangee"s 

 dans une nieme classe et ont une nieme origine : mais on peut raissonablement supposef que les causes qui arnenent les 

 unes peuvent favoriser la naissance des autres." 



"Wartmann 2 has also argued in favor of the common origin of shooting stars and the 

 aurora, resting his proof on a few coincidences, such as those which happened on Decem- 

 ber 16, 1830; October 18, 1836, July 28, 1837; May 7, September 2, and October 22, 

 1839 ; July 5 and September 21, 1840. Facts such as the following have been quoted 

 by others as indicating a relationship between the shooting stars and the aurora. Von 

 Wrangel 3 observed, while in Siberia, that when shooting stars crossed the path of the 

 aurora fiery beams started up in the space traversed. Airy 4 saw a single star shoot 

 from the auroral beams of March 13, 1833. Bravais, while in Scandinavia, recorded one 

 example of stars shooting from the region of the aurora. 5 



iNouv. Mem. de l'Acad. Royale de Bruxelles. XV. 14. 



2 Bibliotheque Universelle, XXX. 206 ; and Quetelet's Correspond. Math, et Phys. XI. 182. 



'Edinburgh New Phil. Journal, 1827, III. 381. 4 London Philosophical Magazine, 3d Series, II. 316. 



6 See also on the same subject Wochenschrift fiir Astronomie, &c, II. 287. 



