JEB4853819 Symbolic representation of the Universe. Detail of a siren mosaic in Rome, 12th century (mosaic); 360x440 cm; (add.info.: Romanesque mosaic of the four rivers, 12th century, pavement of the altar of the chapel of Saint Nicholas, inside the Old Episcopal Palace. Around the polar star, the four rivers of Earth Paradise (Tiger, Euphrates, Gehon and Phison) are figures in the form of heads of human bulls spitting nets of water. Each river is associated with a symbol probably alluding to the different periods of Holy History. The West-East part dedicated to the land and freshwater animals, fish, crayfish, pelican, dog and stork. The marine world occupies the northeast corner with red waves, black algae and fish. The four cardinal points are symbolized by wind heads and rosettes. A red stream represents the Ocean River that surrounds the Earth. The southeast part evokes the vegetation born by water and that pecked birds. (Drome)); by Jean Bernard.