100 



ON THE PERIODICITY OF THE AURORA BOREALIS. 



Oct. 31. Muncke, Arago, and Quetelet. 1 

 " 31. Near Sunderland. Kennie. 2 



1819. 3 



Paris ? Arago. 



Boston. Hale. Lovering. 



Salem. Holyoke. Lovering. 



New Haven. Day. Loomis. Aberdeenshire.* 



Boston. Hale. Lovering. 



Salem. Holyoke. Lovering. 



Salem. Holyoke. Lovering. 



At sea, Lat. 59° N. Long. 59° W. Franklin. 6 



At sea, Lat. 74° N. Long. 111° Jr. Parry.' 



Upper Portage, Lat. 55° N.L'g. 94°. Franklin. 



Zurich. Gilbert. 8 



Gilbert." 



Fhnsburg, Siceden. Boue. 10 



Lake Winnepeg. Franklin. 



Boston. Hale. Lovering. 



New Haven. Day. Loomis. 



G. Britain or Ireland. Dalton. 



Cedar Lake, Lat. 53° N. L'g. 100°. Frauklin. 



Winter Harbor. Parry. 



Suffolk. Forster. 



Barton Mills. Muncke, Arago, and Quetelet. 11 



Gosport. Burney. Scotland. Forster. 12 



G. Britain or Ireland. Dalton. 



Near Diss. Muncke, Arago, and Quetelet. 18 



Wittier Harbor. Parry. Arago. 



Winter Harbor. Fisher. Parry. 



Gosport. Burney. 14 



Winter Harbor. Parry. 



1 Oeuvres de Arago. IV. 607. Annals of Phil. XIII. 71. 



2 Ann. Chem. et Phys. X. 123.. 



8 Auroras were seen at Williamstown, by Dewey, on four- 

 teen evenings during this year, six of which were in October. 



4 Quart. Journ. Sci. VII. 188. 



6 Narrative of a Journey, &c. p. 12. 



6 Hood states that the number of auroras visible at Cumberland 

 House in Lat. 54° N. and Long. 102° W. was, in September, 1819, 

 two; in October, tliree; in November, three ; in December, Jive ; in 

 January, 1820, Jive; in February, seven ; in March, sixteen; in 

 April, fifteen ; and in May, eleven. 



* Parry's Journal of a voyage, p. 93. 



8 Gilbert. Ann. LXVI. 422. 



9 Gilbert. Ann. LXVI. 423. 



10 Quart. Journ. Sci. IX. 210. 

 " Phil. Mag. LIV. 390. 



w Annals of Phil. XIV. 395. 

 » Phil. Mag. LIV. 390. 

 l« Ann. Phil. XIII. 444. 



Winter Harbor. Parry. Arago. 



Boston. Hale. Lovering. 



Salem. Holyoke. Lovering. 



New Haven. Day. Loomis. 



Winter Harbor. Parry. Arago. 



Salem. Holyoke. Lovering. 



Cumberland House. Franklin. 



Winter Harbor. Parry. Arago. 



Winter Harbor. Parry. Arago. 



Winter Harbor. Parry. Arago. 1 



Winter Harbor. Parry. Arago. 



Cumberland House. Franklin. 



Cumberland House. Franklin. 



Winter Harbor. Parry. Arago. 



Cumberland House. Franklin. 



Cumberland House. Franklin. 



Cumberland House. Franklin. 



Cumberland House. Franklin. 



< 'mnberland House. Franklin. 



Winter Harbor. Parry. 



Muncke, Arago, and Quetelet. 



G. Britain or Ireland. Dalton. 



Winter Harbor. Parry. Arago and Quetelet. 



Winter Harbor. Parry. Arago and Quetelet. 



Winter Harbor. Parry. Arago and Quetelet. 



1820. 



Arago. 2 



Winter Harbor. Parry. Arago. 



Winter Harbor. Parry. Arago. 



G. Britain or Ireland. Dalton. 



Arago, Muncke, and Quetelet. 



Cumberland House. Franklin. 



Winter Harbor. Parry. 8 



Cumberland House. Franklin. 



Cumberland House. Franklin. 



Cumberland House. Franklin. 



Cumberland House. Franklin. 



Winter Harbor. Parry. Arago. 



Cumberland House. Franklin. 



Winter Harbor. Parry. Arago. 



Paris ? Arago. 



Cumberland House. Franklin. 



Winter Harbor. Parry. Arago. 



G. Britain or Ireland. Dalton. Arago. 



Cumberland House. Franklin. 



Cumberland House. Franklin. Arago. 



1 Fisher's Journal of a voyage, &.C. p. 156. 



2 Probably a mistake for Jan. 15. 



3 Edin. Phil. Journ. V. 204. 



