368 Notice of two halos with parhelia: 
Ant. XIX.—WNotiee of two halos with parhelia. 
1. Communicated by Isaac Lea, in a letter to the Editor, dated 
PurLADELPHIA, Feb.6, 1826. 
My Dear Sir, 
I] nave great pleasure in handing youa diagramand descrip- 
tion of a halo, with parhelia, seen by my brotherin Jackson, 
Tennessee, August 19th, 1825. The combination of the cir- 
clesis remarkably beautiful, and the beholders must have been 
struck with delight on viewing so beautiful a phenomenon. 
Among the numerous parhelia described by Huygens Halley, 
Herelius Gassendi, &c. I find none that were equal to this in 
its beautiful combinations. 
In accounting for parhelia, most philosophers, particularly 
Newton, ascribe them to the refraction of floating particles of 
hail or snow, and this is most likely to be their cause, as the 
refraction of their regular forms may be accurately calculated. 
M. Mariotte and Mr. Wood attribute them to vapour 
which they say with Halley, consists of hollow sphericles of 
water, filled with an elastic fluid, and that the halos are pro- 
duced by their refraction and reflection. 
I am, very respectfully, your obedient servant, 
ISAAC LEA, 
At 9 o’elock the phenomenon first made its appearance— 
the weather hazy in a slight degree, 45 minutes past 9 the 
haziness increased—15 minutes past 11 o’clock it continued 
‘to increase, and the halo disappeared. 
‘The thermometer for several days had ranged from 96° to 
101° and a heavy thunder-storm, without rain, occurred the 
night previous. 
The citizens of Huntingdon 35 miles east of Jackson, were 
gratified with a view of this splendid exhibition of nature, but 
it was not visible at Reynoldsburg, 65 miles E. of Jackson. 
(See the plate.) 
A the Zenith. 
B the true sun. 
C represents the 7 parhelia formed by the incidence of the 
circles. 
D D two small segments of a large circle. 
FW East and West points of the compass. 
