At Volsinii, in Etruria, a nail was driven every year in the Temple of Nortia, the Fortuna of Etruscan mythology, in order to keep a reckoning of the years (Liv.vii. 3
). This custom was introduced into Rome from Etruria, probably
by the Tarquins, when they founded the Temple of Iupiter Optimus Maximus. An ancient law
enacted that a nail should be driven each year by the chief magistrate on the Ides of
September into the side of the cella
of Iupiter on the Capitol. As the
Romans thus kept a reckoning of their years, when letters were yet scarcely in use, this nail
was called clavus annalis.
( Liv. l. c.; Fest. p. 56, M.). This practice
fell into disuse, but was afterwards revived, not for the purpose of marking the year, but
from a superstitious feeling that any great calamity, such as a pestilence, would be averted
if this ceremony was performed by the supreme magistrate. Hence we read of a dictator being
appointed, more than once, for the sole purpose of driving in the nail (clavi
, Liv. l. c.).