OF THE AURORA BOREALIS. 17 



I have before me minute descriptions of this grand aurora covering a region of 

 six degrees of latitude from N. to S. and extending indefinitely from E. to W. 1 In 

 all those places, the phenomena were remarkably uniform; all observers remarked 

 the early commencement of the display (before the end of twilight) — the predomi- 

 nance of crimson vapor — the broad and splendid arches — the sudden increase of 

 intensity about 7 o'clock, and the formation of the corona soon after around the 

 Pleiades — and the general illumination and fiery appearance of the canopy extend- 

 ing far towards the southern horizon. Numbers also mention the renewal of the 

 principal features with augmented splendor, from half past ten to half past eleven 

 o'clock, although comparatively few observers had the perseverance to follow out 

 their observations through the whole nisht. 



The same year (1837) afforded two other exhibitions of auroras of the first class, 

 namely, on the 1st of July and on the 14th of November. According to Professor 

 Dewey, that of July 1st, as seen at Rochester, N. Y., exceeded in splendor that of 

 January 25th. 2 It followed a sudden depression of temperature. At 2 o'clock P. M. 

 the preceding day, the thermometer was at 86°; a shower ensued, a cool wind 

 set in, and the following evening the thermometer fell to 58°. Soon after twilight 

 the aurora appeared in short, flocculent, cloud-like forms, all across the northern sky. 

 Soon it extended quite round to the east and west points, at both of which broad 

 and bright arches arose, and extended more than half-way to the zenith, while 

 numerous streamers rose all around the northern sky towards the same point. The 

 corona was formed ten minutes after ten o'clock, but the display was more striking 

 at half past ten. The whole expanse except the south was most splendid; and 

 soon afterwards the flashing towards the vertex from all sides was renewed with 

 great power. The maximum of intensity was about 11 o'clock. The colors were 

 constantly changing; from all the northern, eastern, and western parts, the flashing- 

 light rose to the vertex and seemed to shoot back again. Often the light would 

 flash through thirty or forty degrees, disappear within twenty degrees of the vertex, 

 and reappear flashing as before, for the last ten degrees, as if it passed in the inter- 

 mediate space, through some opaque substances. Mr. E. C. llerrick's description of 

 the same aurora, 3 corresponds in most particulars to that of Professor Dewey. At 

 half past ten the action appeared to him most energetic, and the scene eminently 

 beautiful. From east, north, and west, and all points between, streamers shot up 

 from near the horizon in quick succession, with wonderful celerity, and passed be- 

 yond the zenith; while others, starting from an elevation of about 30° in the south 

 met the former about the corona. The display began to decline at 11 h. 10 m., 

 and by midnight became quite faint. At 2 o'clock the aurora began to revive, and 

 soon presented a spectacle in many respects surpassing the former. The exhibition 



1 It was accurately observed and described by Judge McCord, at Montreal ; by Professor Dewey, at 

 Rochester; by Mr. R. Haskius, at Buffalo; by Mrs. G. S. Silliman, at Brooklyn, X. Y. ; by Mr. E. H. 

 Burritt, New Britain, Ct. ; by President Humphreys, at Annapolis, Maryland; also, by a spectator, 

 at Norristown, Pennsylvania, and another in Sussex, New Jersey. Also, at Bermuda. 



' Amer. Journal Sci., XXXIII, 143. 



3 New Haven Daily Herald, for July 6, 183?. 

 3 



