150 GREEK AND ROMAN MYTHOLOGY prayers and offerings; indeed, he was regarded even at a very early period as the pnncipium, and the father of the gods. 195. The chief sanctuary of this god, the Janus Gemi- nus, or Quinnus, situated at the north end of the Forum, opposite 'the sanctuary of Vesta, which served as the common hearth of the State, was the very ancient arched doorway or entrance of the Forum, which was itself pat- terned after the atrium of a house. The doors on the two sides of the passageway were kept open as long as an army was in the field, probably for the reason that at one time the king himself used to march with his troops to war, and it was necessary that the city gate should stand open for him until his return, as the house door did for the father of the family. Under the archway stood an image of the god with two faces, one looking outward and one inward. Although this image was probably patterned after Greek models, yet it is clear that the intention was to express by it the attentiveness and watchfulness which are characteristic of a door- keeper. Like a real janitor (' doorkeeper '), he carried a key and a switch or staff (virga) for driving away troublesome intruders ; and the nature of his activity was indicated by the epithets Patulcius (' opener '), and Clusivms or Clusius (' closer'). His other principal ancient place of worship was the hill named for him Janiculum, on which king Ancus Marcius had built a fortress, to protect the commercial road leading into Etruria, and the harbor in the Tiber situated at its foot. So from being the god of entrance and departure he became the protector of commerce and navigation; his head and the prow of a ship were stamped
