102 OF THE HALO, CORONA, CHAP. 2. 19. 



Coronae are of various sizes, according to the 

 peculiarities of the intervening vapour : but 

 they seldom exceed 10 in diameter : they are 

 generally faintly coloured at their edges. 



Frequently, when there is a Halo encircling 

 the moon, there is a small Corona more imme- 

 diately round it. Coronae, as well as Halones, 

 have been always observed to prognosticate 

 Rain, Hail, or Snow. As far as I can observe 

 they are generally seen in the cirrostratus cloud. 

 CORONA DVPLEX. Discus lucidus, alium 

 discum paulo lucidiorem ac minorem inclu- 

 detis, in quorum centra communi Sol vel 

 Luna videtur. 



A double Corona is very common : sometimes 

 they are triple or quadruple. 



PARHELION. PL VI. Fig. 5. Imago Soils 



falsa., vel plures imagines ejusdem generis 



circa Solem circulatim dispositae, et magis 



minusve lialonibus aliisque lucidis vittis 



commitatae. 



Parhelia vary considerably in general appear- 

 ance : sometimes the sun is encircled by a large 

 Halo, in the circumference of which the Mock 

 Suns usually appear: these have often small 

 Halones round them : they have usually a 

 horizontal band of white light of a pyramidal 



