Remarkable Atmospheric Appearances. ' 331 
er concentration of the rays of light, which being again 
thrown off on the more distant and less dense medium, would 
form the great circle, extending below the horizon in the N. 
E. and crossing the third circles in a direction, if continued, 
to meet at the southwestern limb of the primary halo. 
That these are the causes of those wonderful phenomena 
seems confirmed by the north-east gale that followed, com- 
mencig on Monday evening, and by the abundance of rain 
which has since fallen. At this place the rain commenced 
on the 9th, at night, and fell in torrents, almost without in- 
termission, for eight days in succession. A. 
[From the National Intelligencer.] 
Extracts of a letter from Dr. S. L. Mitchill, dated Oc- 
tober 4, 1816.—*“I thank you for your account of the halo 
of September 8, accompanied with a drawing. Under a 
conviction that such natural appearances ought to be record- 
ed for the benefit of the present time, and the information of 
our successors, I caused the most remarkable meteor of this 
kind that I ever beheld, to be delineated and preserved in the 
Medical Repository. In the 10th volume of that work, its 
history and figures may be seen ; where, in addition to two 
circles, like those you observed, there were five parhelia, 
and two of them tailed. 
‘* As to a theory of the colors which are produced by the 
reflection and refraction of light in the rainbow, it requires 
an alteration or modification to suit the case of halos and 
ing subjects of modern science. It seems to be a casus 
omissus or pretermissus in the Newtonian doctrine. An 
ardent genius in our country might supply the hiatus. 
I view the reasonings of *‘ A,” in the Rhode-Island Re- 
publican, republished in the National Intelligencer, Oct. 3, 
as being superior to any thing I have seen on this subject. 
Washington City, Oct. 11. 
