Omphălus
(
ὀμφαλός). Literally “the navel” (
umbilicus), and applied to anything like the navel, round—e. g the
knobs or bosses on a shield (see
Clipeus), a knob on
the yoke of a horse for fastening the reins, and, figuratively, the centre of anything. Thus
Ogygia, the island of Calypso, is called
ὀμφαλὸς θαλάσσης,
and
Delphi (q.v.) was also called
ὀμφαλός, as being the supposed centre of the earth, from which,
according to the myth, Zeus once despatched two eagles, one flying eastward and the other
westward, with the result that they met again at Delphi. A marble boss marked the exact spot
where they met.