ON THE 



RECENT SECULAR PERIOD OF THE AURORA BOREALIS. 



On the evening of the 27th of August, 1827, after a long absence of any striking 

 exhibition of the Aurora Borealis, there commenced a series of these meteors which 

 increased in frequency and magnificence for the ten following years, arrived at a 

 maximum during the years 1835, 183G, and 1837, and after that period regularly 

 declined in number-and intensity until November, 1848, when the series appeared 

 to come to a close. The recurrence, however, of three very remarkable exhibitions 

 of the meteor, in September, 1851, and of another of the first class as late as 

 February 19th, 1852, indicates that the close was not so abrupt as was at first 

 supposed ; but still there was a very marked decline in the number of great auroras 

 after 1848, and there has been scarcely one of the higher class since 1853. 



A review of the history of the foregoing series of Auroras, appears to warrant 

 the conclusion that it constituted a definite period, which I have ventured to call 

 the "Secular Period," having a duration of a little more than 20 years; increasing 

 in intensity pretty regularly for the first ten years, arriving at its maximum about 

 the middle of this period, and as regularly declining during the latter half of the 

 same period. 



It has appeared to me incumbent on some one devoted to the studies of nature, 

 who has witnessed this exhibition of the Aurora Borealis, probably among the 

 most remarkable that have ever occurred since the creation of the world, to write 

 its history; to give an accurate description of its varieties; to present at one 

 view a classification of the principal facts, in order, if possible, to ascertain the 

 laws of the phenomenon ; and finally, to determine the origin, or primary cause to 

 which it may be referred. I am the more encouraged to undertake this labor, from 

 having enjoyed peculiarly favorable opportunities for observing these exhibitions 

 from their commencement, and from having amassed, from the accounts published 

 in the periodicals of the day, and from an extensive correspondence, a greater 

 amount of facts, than, so far as I know, any other person has taken the trouble to 

 accumulate. 



I know of no other method of successfully investigating a subject of this kind, 

 than, first, to examine all the facts of the case ; secondly, to bring together into 



