43:1 · Signs with the structural characteristics of this group seem few in Western ideography. Oddly enough, one of the very few signs used means mirage. Mirage is a hot air phenomenon that occurs in deserts and at sea when air of different temperatures, and thus different density, forms layers. Distant objects and landscapes can appear to be close, and some persons can perceive things not known to exist in objective reality.
    One well-known mirage phenomenon is the Fata Morgana, seen off the coasts of southern Italy.