77. Zosimus (1. v. [c. 41] p. 355, 356) speaks of these
ceremonies like a Greek unacquainted with the national
superstition of Rome and Tuscany. I suspect that they
consisted of two parts, the secret and the public; the
former were probably an imitation of the arts and spells by
which Numa had drawn down Jupiter and his thunder on Mount
Aventine.
--Quid agant laqueis, quae carmina dicant,
Quaque trahant superis sedibus arte Jovem,
Scire nefas homini.
The 'ancilia' or shields of Mars, the 'pignora Imperii',
which were carried in solemn procession on the calends of
March, derived their origin from this mysterious event
(Ovid. Fast. iii. 259-398). It was probably designed to
revive this ancient festival, which had been suppressed by
Theodosius. In that case we recover a chronological date
(March the 1st, A . D . 409) which has not hitherto been
observed .