In the mental view of Homer, then, the passage of Scylla could not lie much beyond the horizon of his own Greek world and of geography proper. This was the more eligible of the two routes. The other was that of the Πλαγκταὶ, or Bosphorus. It was rejected as involving certain destruction: for only Jason had safely passed it by the aid of Juno, and Pallas was not now at hand to succour Ulysses; since he was outside that Greek world, to which her action has been restricted, generally speaking, and in all likelihood for poetical reasons, in the Odyssey. Now, since both these passages are spoken of as apparently lying near the island of the Sirens, which is itself separated, as far as we can judge, by no long interval from Ææa and Circe, the next inferences we have to draw are two of very great importance. The first is, that although the one strait of Homer physically corresponds with the Straits of Messina, while by the other he plainly means the Bosphorus, yet he conceived of these as within no great distance of one another. The second inference is that, according to the belief of Homer, the waters beyond the Bosphorus were accessible by some channel other than that of the Dardanelles and Sea of Marmora: for otherwise Ulysses could not have placed himself on the farther side of those terrible narrows, except by navigating one of them. ~_Three maritime routes to Ocean-mouth._~ There were therefore three maritime routes by which Homer conceived that mouth of Ocean, which Ulysses entered, to be approachable: 1. The route by which the hero actually arrived there: 2. The route of Scylla and Charybdis, by which he returned from it: 3. The route of the Bosphorus, by which Jason had passed, and which Ulysses might, according to the description of Circe, have attempted. But now, what in the view of Homer was this mouth of Ocean? that is, on what geographical basis rested the reports or descriptions which he adopted for the groundwork of his picture? We cannot but admire, as we pass along, the manner in which the Phœnicians guarded the treasures of their distant markets: no way lay to them except through a choice of terrors; terror in the boundless expanse of devouring waters; terror in shipwreck by the Πλαγκταὶ, which none but Jason (so says Circe, the Phœnician witness) had escaped; terror in certain loss of men by the voracious maw of Scylla. What, however, was this Ocean-mouth that lay beyond them? My answer is, that there are two mouths of Ocean, either of which might tolerably correspond with the Homeric picture, if tried only by its relation to the intermediate points that are represented by these dangerous passages. Firstly, the Straits of Gibraltar, leading to the Atlantic. Secondly, the Straits of Kertch or Yenikalè, leading to the Sea of Azof. ~_Straits of Gibraltar as Ocean-mouth._~