~ 
Halos. Sah 299 — 
which puts the matter entirely beyond dispute. While Commodore 
Hardy was lying off Boston, during the late war, his whole ship’s 
_ crew observed, during a particular state of the atmosphere, the figure 
of aman, resembling a sailor of a colossal size reflected in the 
heavens. 
If the particles of the atmosphere had reflected each its respec- 
tive image, the object would have ‘been confused, shapeless and 
obscure. 7 Be 
The halo being thus accounted for, the anthelia, or mock suns 
yet remain to be explained. As yet nothing of this kind has been 
attempted. The best works, within our reach, are silent on the sub- 
ject, but yet it is evident that at the particular points, where they are 
seen, a greater collection, and a greater reflection of homogeneous 
rays must take place than at any other. : 
The idea most obvious is this, that those direct rays of the sun, — 
which would otherwise have passed off uncollected, are attracted to & 
dges of the cloud, drawn within its influence, and then refracted 
sted to the eye of the spectator. 
ae oe 
a." 
2. Lunar.— West Point, March 27, 1831. 
In observing a beautiful halo around the moon, onthe night of the 
20th inst., I was led to consider the cause of this remarkable phe- 
nomenon; [noticed that the inner part of the halo was about 10° from 
_ ‘fe moon, that its breadth was about 3° or 4°, and that the brightest 
__ colors were in the middle of the ring. Near the edge of the moon 
* the sky was of its natural color; as wel! asI could determine, the 
Hor of the concentric rings, which formed the halo, were as follo’ Sy 
(beginning with the inner ring,) pale blue, yellow, orange, and pale 
ue again. 
That this and similar phenomena are occasioned by the watery 
vapors in the atmosphere, is highly probable, and indeed it is ren- 
dered almost certain from the following experiment, which I perform- 
ed a short time after I observed it. I took a clear and smooth piece 
of glass with parallel faces, and after gently blowing the breath upon it, 
held it up so as to look through it at the moon; by means of the 
aqueous vapor which was scattered in very small globules over the 
surface of the glass, the moon’s rays were refracted, producing all 
the different colors which-I had seen in the halo. The variety and 
brightness of the colors can be modified by the quantity of vapor 
which is attached to the glass, and the size of the ring will depend 
Wye 
oe he on 
