6 ON THE RECENT SECULAR PERIOD 



Indeed, in my childhood, nearly fifty years ago, I recollect to have heard very 

 aged people tell of the strange sights which were seen in the air during "the old 

 French Avar" (which closed in 17G3), when, as some of the more ignorant described 

 them, " armies and spearmen were distinctly seen engaged in battle." From 1781, 

 none of equal intensity, it is believed, occurred for nearly half a century. The 

 splendid arch, therefore, and other striking accompaniments of the aurora of August 

 28th, 1827, took us by surprise, and were viewed with wonder by nearly all the 

 existing generation of the countries where it was visible. Immediately after 

 this great aurora, exhibitions of the phenomenon became more frequent than for a 

 long time before, as is obvious from the catalogue of auroras published by the late 

 John Dalton, and appended to the last edition of his Meteorological Essays} The 

 period of seven years, from 1819 to 1826, averaged per annum, in Great Britain 

 but If ; whereas from 1827 to 1834, the average was 16. The number recorded 

 by Dalton in 1826 was only two, while the number for 1827 was ten. 



I observed the great aurora of August, 1827, with the deepest interest ; but 

 having preserved but few notes of it, I avail myself of the accounts published at 

 the time in a paper in the American Journal of Science," communicated by Benja- 

 min D. Silliman, Esq., occasionally, however, drawing upon my own recollections. 



The appearances of the aurora were found to be nearly uniform in all the North- 

 ern States of the Union. It was first observed at New Haven at haf-past nine 

 o'clock, at which time the light resembled that of a fire at some distance, and was 

 by many attributed to that cause. The light, however, soon became more intense, 

 and its outline better defined, gradually assuming a columnar shape, and extending 

 from about N. N. W. to E. N. E. At 9 h. 45 m., waves of light, in detached masses, 

 but all in the line of the luminous arch, began to flow from east to west, until the 

 whole were blended, and the heavens were adorned with a beautiful arch, culmi- 

 nating at a point about 15° north of the zenith. The greatest breadth of the arch, 

 at its centre, was 9 or 10 degrees, and it tapered from that point to its western 

 extremity, where the light was much brighter. The eastern segment was at no 

 time so distinct as the western, but was rendered very beautiful by the constant 

 passage of waves of apparently illuminated vapor, the lines of which were at right 

 angles to the line of the arch, and extended from north to south. Their westward 

 motion was contrary to the course of the wind. The whole arch moved with a 

 gradual and nearly uniform motion toward the south, and passed the zenith about 

 10 h. 45m., presenting to the eye through its whole length, a broad bright band of 

 wavy light, studded with stars which were seen distinctly through it. The color 

 was a shining white. This arch was remarkable for its duration, which was nearly 

 two hours. A great bank of light lay almost constantly above the northern hori- 

 zon, sometimes surmounted by, and sometimes resting upon, a dark cloud, which 

 was visible during the whole time. 3 This was visible in the same situation at sea, 



1 Meteor. Observations and Essays, Ed. 2d, p. 218. 3 Vol. XIV. 



3 It may be doubtful whether this was anything more than the naked sky, which, by contrast with the 

 illuminated portion often resembles a dark cloud. In (he aurora of September 29th, 1851, the base of 



