Cācus
In Italian mythology, a fire-spitting giant, the son of Vulcan, who lived near the place
where Rome was afterwards built. When Hercules came into the neighbourhood with the cattle of
Geryon, Cacus stole some of them while the hero was sleeping and dragged them backwards into
his cave under a spur of the Aventine, so that their footprints gave no clue to the direction
in which they had gone. He then closed the entrance to the cave with a rock, which ten pairs
of oxen were unable to move. But the lowing of the cattle guided the hero, in his search, to
the right track. He tore open the cave, and, after a fearful struggle, slew Cacus with his
club (Ovid,
Fast. i. 543 foll). Upon this he built an altar on the spot to Iupiter,
under the title of Pater Inventor, “the discoverer,” and sacrificed one of
the cattle upon it. The inhabitants paid him every honour for freeing them of the monster; and
Evander, who had been instructed by his mother, Carmentis, in the lore of prophecy, saluted
him as a god. Hercules is then said to have established his own religious service, and to have
instructed two noble families, the Potitii and the Pinarii, in the usages to be observed at
the sacrifice (
Livy, i. 7). This sacrifice was to be offered on the
Ara Maxima, which he himself had built on the cattle-market (
Forum
Boarium) where the cattle had been pastured.
