SI 14 Account of Hahs and Parhelia in America. 



halo on its south-west limb where they united. This halo 

 AB was double the diameter of the one round S, and had 

 mock suns at A and B. The rays of light from A formed 

 another circle m n (said to be double the diameter of A B, 

 though the original figure does not so represent it,) and the 

 rays from B a similar one n p. The rays of light thrown off 

 at the crossing of these circles at w, formed segments g r of a. 

 fifth halo, about 120® of which was below the horizon. 



A halo was seen on the 19th August 1825 in Tod County, 

 Kentucky, which is shown in Plate I. Fig. 4. If we suppose E 

 and W the east and west points, A the zenith, and B the sun, 

 then CC is a circle with the prismatic colours of exceeding bril- 

 liancy, D D a very bright luminous circle passing through the 

 sun B, E E, E E, two segments of circles intersecting D D at 

 F. These segments were very bright about F, but became 

 gradually invisible as they approached the sun. The points 

 B, A, F were in a straight line, and the intersection F was 

 the same height above the horizon as the sun, and moved 

 north and approached the zenith, in the same proportion as 

 the sun moved south, and approached the zenith. The circle 

 D D, and the segments E E, EE, had the same diameter, and 

 diminished in size as the sun approached the zenith. These 

 circles were first observed about eight o'*clock, and continued till 

 eleven. There was not a cloud to be seen, and the haze was 

 so thick high up in the atmosphere, that the sky appeared 

 completely black, and the sun shone with so much splendour, 

 and there was such a glare, that it was painful to the eyes 

 to go into the light. 



On the Friday following the same phenomenon appeared, 

 with the addition of an elliptical halo m w, less brilliant than 

 the external one. 



On the 19th August 1825, there was seen at Jackson, in 

 Tennessee, the halo shown in Plate I. Fig. 5, which is the 

 same nearly as the one above described, and seen on the same 

 day in Tod county. A is the zenith, B the true sun, C C, &c. 

 are the parhelia formed by the intersection of the circles, D D 

 two small segments of a large circle, and E, W, the east and 

 west points of the compass. The luminous circle had much 

 the appearance of a lunar rainbow ; that part of the small cir- 



