There is a similar variety of colours in _Halos_. But there is this difference in the various phenomena: Halos are formed at any point in the sky, wherever there is a heavenly body; rainbows are not found except opposite the sun; streaks, only in the neighbourhood of the sun. I may express their difference in another way: Bisect a halo and you have a rainbow; make it a straight line and you have a streak. In all three there is the same multiplicity of colours, the scale running from dark blue to orange. Streaks, then, are found only close to the sun. Rainbows are all either solar or lunar. Halos are seen with all the heavenly bodies. XI Another kind of streak is visible when thin rays of bright light 1 equidistant from one another are shot out through narrow apertures in the clouds. These, too, are a prognostication of rain. How am I to express myself here? What shall I call them? Images of the sun? The chroniclers call them merely suns, and have put on record that they have been seen in twos and threes. The Greeks call them _Mock 2 Suns_ (parelia = beside the sun), because they are generally seen in proximity to the sun, and somewhat resemble the sun. They do not give a complete reproduction of the sun, but exhibit only his size and shape. They are dull, however, and languid without any of his heat. What name are we to apply to them? Shall I do as Virgil did---hesitating about the name, employ the very name which causes the hesitation? And by what name[31] shall I call you, Rhaetian wine? But yet you must not seek to compete with the Falernian bins. [31] He has altered Virgil’s word “carmine” to “nomine” to suit his meaning, or, as the editors say, _lapsu memoriae_. There is no objection to my calling these, mock suns. They are, in fact, images of the sun formed in a thick cloud close to him after 3 the fashion of a mirror. Some writers define a mock sun as a cloud, round, bright, and resembling the sun. The mock sun follows the sun, and is never left farther behind him in his orbit than it was at its first appearance. None of us, I suppose, is surprised at seeing a reflection of the sun in some fountain or quiet lake. Well, his disc may be reflected in the heavens just as readily as on earth, if only the material is suitable to produce the reflection. XII