AMERICAN 
JOURNAL OF SCIENCE, &c. 
Ant. 1.—Observations upon certain Auroral and Optical Phe- 
nomena; by ALexanper C, Twrnine. 
Tue height of auroral phenomena is a subject which has divided 
| philosophers. Some consider them as lying in the lower regions of 
the atmosphere ; while others would elevate them beyond its sup- 
posed limits, or at least into its extreme upper regions. It is my in- 
tention to prove in three instances of late occurrence, that the latter 
opinion is the true one. 
Auroral Cloud of December, 1835. 
On the evening of the 10th of December, 1835, being at the village 
of New Britain, which is twenty six miles N. and 15° E. from the 
city of New Haven, [ observed attentively, for more than an hour, 
an auroral cloud of very unusual appearance. At the beginning of 
my observations, about half past § o’clock, P. M. it was situated 
about 25° east of north, and at an average altitude of 11°. The 
star Beta Ursae Majoris was enveloped in its upper portion, but not 
obscured. 
This altitude changed only 9° during the period of my observa- 
tions; although the cloud moved horizontally towards the west not 
less than 20° in the same time. The cloud had a horizontal extent 
of at first about 16°; but was narrow (only 4°) in the vertical di- 
rection,—being srigigoee in its upper outline, but shaped, on the 
whole, somewhat like a very excentric semi-ellipse. Its lower limit 
however was a well defined line; and in respect of this feature the 
cloud continued Beg whenever it was visible, through all its 
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Vou. SAAN —No. 2 
