_Parhelia._ Mock suns, in the vicinity of the real orb, are due to the same cause as haloes, which appear in connection with them. Luminous circles, or segments, crossing one another, produce conspicuous masses of light by their united intensities, and the points of intersection appear studded with the solar image. This is a meteorological rarity in our latitude, but a very frequent spectacle in the arctic climes. In Iceland, during the severe winter of 1615, it is related that the sun, when seen, was always accompanied by two, four, five, and even nine of these illusions. Captain Parry describes a remarkably gorgeous appearance, during his winter sojourn at Melville Island, which continued from noon until six o’clock in the evening. It consisted of one complete halo, 45° in diameter, with segments of several others, displaying in parts the colors of the rainbow. Besides these, there was another perfect ring of a pale white color, which went right round the sky, parallel with the horizon, and at a distance from it equal to the sun’s altitude; and a horizontal band of white light appeared passing through the sun. Where the band and the inner halo cut each other, there were two parhelia, and another close to the horizon, directly under the sun, which formed the most brilliant part of the spectacle, being exactly like the sun, slightly obscured by a thin cloud at his rising or setting. A drawing of this parhelion is given by Captain Parry, who remarks upon having always observed such phenomena attended with a little snow falling, or rather small spicula or fine crystals of ice. The angular forms of the crystals determine the rays of light in different directions, and originate the consequent visual variety. We have various observations of parhelia seen in different parts of Europe, which in a less enlightened age excited consternation, and were regarded as portentous. Matthew Paris relates in his history:—“A wonderful sight was seen in England, A. D. 1233, April 8, in the fifth year of the reign of Henry III., and lasted from sunrise till noon. At the same time on the 8th of April, about one o’clock, in the borders of Herefordshire and Worcestershire, besides the true sun, there appeared in the sky four mock suns of a red color; also a certain large circle of the color of crystal, about two feet broad, which encompassed all England as it were. There went out semicircles from the side of it, at whose intersection the four mock suns were situated, the true sun being in the east, and the air very clear. And because this monstrous prodigy cannot be described by words, I have represented it by a scheme, which shows immediately how the heavens were circled. The appearance was painted in this manner by many people, for the wonderful novelty of it.”