Many local gods were identified with Apollo both in his capacity of god of healing and also that of god of light.[61] The two functions are not incompatible, and this is suggested by the name Grannos, god of thermal springs both in Britain and on the Continent. The name is connected with a root which gives words meaning "burning," "shining," etc., and from which comes also Irish _grian_, "sun." The god is still remembered in a chant sung round bonfires in Auvergne. A sheaf of corn is set on fire, and called "Granno mio," while the people sing, "Granno, my friend; Granno, my father; Granno, my mother."[62] Another god of thermal springs was Borvo, Bormo, or Bormanus, whose name is derived from _borvo_, whence Welsh _berw_, "boiling," and is evidently connected with the bubbling of the springs.[63] Votive tablets inscribed Grannos or Borvo show that the offerers desired healing for themselves or others. The name Belenos found over a wide area, but mainly in Aquileia, comes from _belo-s_, bright, and probably means "the shining one." It is thus the name of a Celtic sun-god, equated with Apollo in that character. If he is the Belinus referred to by Geoffrey of Monmouth,[64] his cult must have extended into Britain from the Continent, and he is often mentioned by classical writers, while much later Ausonius speaks of his priest in Gaul.[65] Many place and personal names point to the popularity of his cult, and inscriptions show that he, too, was a god of health and of healing-springs. The plant _Belinuntia_ was called after him and venerated for its healing powers.[66] The sun-god's functions of light and fertility easily passed over into those of health-giving, as our study of Celtic festivals will show. A god with the name Maponos, connected with words denoting "youthfulness," is found in England and Gaul, equated with Apollo, who himself is called _Bonus Puer_ in a Dacian inscription. Another god Mogons or Mogounos, whose name is derived from _Mago_, "to increase," and suggests the idea of youthful strength, may be a form of the sun-god, though some evidence points to his having been a sky-god.[67] The Celtic Apollo is referred to by classical writers. Diodorus speaks of his circular temple in an island of the Hyperboreans, adorned with votive offerings. The kings of the city where the temple stood, and its overseers, were called "Boreads," and every nineteenth year the god appeared dancing in the sky at the spring equinox.[68] The identifications of the temple with Stonehenge and of the Boreads with the Bards are quite hypothetical. Apollonius says that the Celts regarded the waters of Eridanus as due to the tears of Apollo--probably a native myth attributing the creation of springs and rivers to the tears of a god, equated by the Greeks with Apollo.[69] The Celtic sun-god, as has been seen, was a god of healing springs.