Farther to the west from these Pillars there is boundless sea. Himilco relates that ... none has sailed ships over these waters, because propelling winds are lacking ... likewise because darkness screens the light of day with a sort of clothing, and because a fog always conceals the sea.[34] [Illustration: FIG. 1--Map of the Sargasso Sea showing its relation to the Azores, to illustrate its possible bearing on the medieval belief in the existence of lands or islands beyond. Scale 1:72,000,000. (The map is also intended to help in locating the various existing islands of the North Atlantic.)] Aristotle, as cited by Nansen, tells us in his “Meteorologica” that the sea beyond the Pillars of Hercules was muddy and shallow and little stirred by the winds.[35] In early life Aristotle was a pupil of Plato, and, though he afterward developed a widely different method and outlook, it is likely that their information as to this matter was in common, being supplied perhaps by Phoenician and other seamen. In the passage quoted from Scylax and the first excerpt from Avienus the courses referred to are apparently too near the mainland shore to approach that prodigious accumulation of eddy-borne weeds in dead water which has long given to a great space of mid-Atlantic the name of the Sargasso Sea. But they show that huge seaweeds were very early associated with obstruction to navigation in seafaring minds and popular fancy. Perhaps they may also have suggested shallows as affording beds of nourishment for so enormous an output of vegetation. It would not readily occur to the early seagoing observers that the greatest of these entangling creations floated in masses quite free, though we now know this to be the case. In any event, it is evident that some imperfect knowledge of conditions far west of the Pillars of Hercules had made its way to Greece. Somewhere in that ocean of obscurity and mystery there was a vast dead and stagnant sea, presumably shallow, a sea to be shunned. Gigantic entrapping weeds and wallowing sea monsters freely distributed were recognized, too, as among the standing terrors of the Atlantic. THE SARGASSO SEA AS THE ANCIENT ATLANTIS