20 ON THE RECENT SECULAR PERIOD 



This was often repeated. The southern part of the heavens was occupied by 

 streamers to a very unusual extent. The arch bounding the aurora on the south 

 gradually descended, so that, at 10 o'clock, its vertex was not more than 10° above 

 the horizon. 



The observations made with the magnetic needle, though not very accurate, were 

 sufficient to show that it was greatly affected. 



As late as 1 o'clock, the spectacle, after having declined, was renewed with great 

 splendor, and waves and streamers were numerous until daylight. 



At Nashville, Tennessee, lat. 36°, this auroral exhibition was more striking than 

 any one seen within the memory of the oldest inhabitants; yet the phenomena were 

 far less imposing than at New Haven. No corona was formed. The northern bank 

 of auroral vapor attained its greatest height at 8 h. 40 m., having then an 

 altitude of 25°. It was soon after this period that, at the north, the aurora was 

 putting on its finest forms. 1 Even as far south as New Orleans, lat. 29° 58', the 

 auroral display was so conspicuous that it was mistaken for a great conflagration, 

 and the fire companies were out. On the corresponding evening, London was strik- 

 ingly illuminated by the auroral lights. At 2 o'clock in the morning, the pheno- 

 menon was described as exceedingly gorgeous. It was accompanied by numerous 

 meteors or shooting stars. 



The year 1840 was productive of a great number of auroras of the third and 

 fourth classes, but of none of the highest class. The entire number recorded in 

 the Regents' Report was no less than 75. That of May 29th was the most remark- 

 able. Those of August 10th, and September 25th, and December 25th, were of 

 superior brilliancy. 



The record for 1841 was nearly the same in respect to number, being 72 ; but 

 only one was characterized as peculiarly splendid, and that occurred Nov. 18th. 



The year 1842 shows a great decline in numbers, only 36 being recorded in the 

 Regents' Report for that year; and of these only one, that of April 15th, was at all 

 remarkable. 



The report for 1843 gives 55, an increase of number, but a diminution of inten- 

 sity, as none occurred of the first or second class. That for 1844 shows a still 

 further decline, being 30. Again, that for 1845 gives only 25. Neither year .was 

 distinguished for any exhibition of the higher orders. The year 1846 indicates a 

 rapid increase, the number being 47; and the following year, 1847, has 46, of which 

 those of March 19th, April 7th, and November 25th, were characterized by some, 

 though not by all, of the features of the highest class. In all three, the maxi- 

 mum of intensity was near 11 o'clock. The year 1848 was, however, distin- 

 guished by a larger number, 64, and for two auroras of superior brilliancy, which 

 occurred April 6th and November 17th. Of the former, my note-book has the 

 following passage: "In all the exhibitions of the aurora borealis which I have 

 seen, I have never before been so much struck with the resemblance of the flashes, 

 as they succeeded each other from near the horizon towards the zenith, to the 



1 Amcr. Jour., XXXVIII, 263. 



