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Mock suns are wont to be formed in pairs and on the same principle. There is nothing, in fact, to prevent the formation of as many as there are clouds suitable for exhibiting an image of the sun. Some writers are inclined to hold that when two such phantoms are visible, one arises directly from the sun, the other from his image. For, to use an illustration from common experience, when several mirrors are so arranged that one is in sight of the other, all reflect the same image; but only one is directly from the original, the rest are reflections of images. The nature of the object presented to the mirror makes no difference in the effect. Whatever it sees it reproduces. So, up on high there, if some chance has so disposed the clouds that they face one another, one of them reflects the image of the sun, the other the image of his image. The clouds that produce this effect must be dense, smooth, bright and flat, analogous in character to the sun. All phantoms of this kind are white and resemble so many discs of the moon, for the reason that the sun’s light that they receive and reflect back is always oblique. If the cloud, on the contrary, is beneath the sun and too near him, his rays dispel it: or again, if situated too far away, it does not reflect them nor produce any image. In ordinary experience in the same way mirrors withdrawn to a distance from us do not reproduce our features because our sight cannot carry back to us from them.
These suns, too—to employ the name given by the chroniclers,—are an indication of rain, especially if they have their position in a southern quarter, from which the most heavily-charged clouds chiefly come up. When such an image surrounds the sun on both sides, then, if we are to believe Aratus, a storm is brewing.