Note 296 — 357ON THE COMMONWEALTH.

This phenomenon of the parhelion, or mock sun, which so puzzled Cicero’s interlocutors, has been very satisfactorily explained by modern science. The parhelia are formed by the reflection of the sunbeams on a cloud properly situated. They usually accompany the coronæ, or luminous circles, and are placed in the same circumference, and at the same height. Their colors resemble that of the rainbow; the red and yellow are towards the side of the sun, and the blue and violet on the other. There are, however, coronæ sometimes seen without parhelia, and vice versâ. Parhelia are double, triple, etc., and in 1629, a parhelion of five suns was seen at Rome, and another of six suns at Arles, 1666.