Notice of an Aurora Borealis. 85 



Art. II. — Notice of the Aurora Borealis,* of April 22. 



We had the good fortune to witness, on the night of the 22d, 

 and morning of the 23d of April, a most magnificent display of 

 northern lights. This phenomenon is but rarely seen in our lati- 

 tude, and more rarely still, appears to us in its highest splendor. 

 As accurate a description, therefore, as may be given of its late 

 remarkable appearance, with a statement of such facts, as may 

 tend in any degree to elucidate the questions which it presents, 

 cannot be unacceptable, and may prove useful. I begin by noting 

 the state of the weather at the time ; although I am not aware that 

 the Aurora either influences it, or is affected by it. The day was 

 fair during the whole of the 22d. A high wind blew from the north- 

 west until mid-day, when it became calm. At night fall, the wind 

 again arose, and increased gradually so as to be moderately high by 

 two o'clock the next morning. At dusk it had shifted to the west. 

 The temperature was 39° at sun-rise of the 22d, and 53° at three 

 o'clock, P. M. From ten o'clock that night until two the following 

 morning, the thermometer stood at 38° ; the barometer remained 

 stationary at 30.00 throughout the evening and night. 



About seven o'clock on the evening of the 22d, it was noticed 

 that a large part of the northern heavens was covered with a thin 

 vapor-like appearance — white at the base — of a pale red at the upper 

 edges, and of a deeper hue, red and yellow intermixed, about the 

 middle. It spread through an arc of sixty degrees near the hori- 

 zon, and extended half way up to the zenith. Before nine o'clock 

 it had disappeared, leaving nothing but a bank of white Auroral 

 vapor, stretching along the north and north-east horizon. At fifteen 

 minutes after ten, on looking towards the north, I perceived a few 

 well-defined columns, shooting up a short distance, each of them 

 appearing and vanishing momentarily ; yet so that to a careless oh-' 

 server, they might seem to remain permanently before the view. 



* To Professor Silliman, Yale College, New Haven. 

 Dear Sir, — The following account of the Aurora Borealis of April 22d, as it 

 appeared at this place, was lately made at the monthly meeting of a Scientific 

 Association, the members of which have requested me to forward it to you, for 

 insertion in your Journal. If you think it sufficiently interesting, 3'ou will oblige 

 me by giving it a place in your next number. 



I am, respectfully, your obedient servant, J. McCaffrey. 



Mt. St. Mary's College, Emmitsburg, May 18th, 1836. 



