The two things together, the sea-water in the cistern and the trident-mark, were both associated with Poseidon. Pausanias[123] says they were said to be ‘the evidence produced by Poseidon in support of his claim to the country.’ Apollodorus[124] says, ‘Poseidon came first to Attica and smote with his trident in the middle of the Acropolis and produced the sea which they now call Erechtheïs.’ Athena produced the olive-tree, Poseidon the salt well and the trident-mark as ‘tokens’ or evidence of their claim. This is manifest aetiology. There had been on the Acropolis from time immemorial certain things reputed sacred, a gnarled olive-tree, a brackish well, three holes in a rock. It was the obvious policy of any divinity who wished to be worshipped at Athens to annex these tokens. Pandrosos had the olive-tree before Athena. The name of the well Erechtheïs shows that it was a ‘token’ of Erechtheus rather than of Poseidon. Such sacred trees, such ‘seas,’ such curious marks existed elsewhere; Pausanias[125] himself notes in another inland place, Aphrodisias in Caria, there was a sea-well. What impressed him as noteworthy about the well at Athens was that when the South wind was blowing it gave forth the sound of waves, but then as he does not say if he waited for a South wind, the ‘sound of waves’ may have been a detail supplied by the guides. * * * * * The trident-mark belongs to a class of sacred things that will repay somewhat closer attention. Fresh light has been thrown upon it by a recent discovery. In examining the roof of the North Porch, with a view to repairs, it was observed that immediately above the trident-mark an opening in the roof had been purposely left. The object is clear; the sacred token had to be left open to the sky; it had to be _sub divo_. This is manifestly more appropriate to a sky-god than to a sea-god. Our best analogies are drawn from Roman sources. Ovid[126] tells us that when the new Capitol was being built a whole multitude of divinities were consulted by augury as to whether they would withdraw to make place for Jupiter. They tactfully consented, all but old Terminus. He stood fast, remaining in his shrine, and still possesses a temple in common with mighty Jupiter: And still, that he may see only heaven’s signs In the roof above him is a little hole. When place was wanted for an Olympian, be he Zeus or Poseidon or Athena, the elder divinities were not always so courteously consulted. We do not even know whose open air token Poseidon seized.