Before the rise of mathematical and physical geography, which Aristotle understood perfectly, though he did not work it out for others, and down to the time of Eratosthenes, the notion of the ancients was, that the north wind, which was so disagreeable to them, came from mount Haemus; to this belief they were probably led by the fact, that they heard of terrific winds blowing on the coast of Thrace—the Greeks told one another things about those winds, which made their hair stand on ends;—they were further told, that in the more northern countries, in Bulgaria, Wallachia, and in general on the northern slopes of mount Haemus, the violence of the winds was not to be compared with what it was in Macedonia and Thrace. Those mountains, therefore, were regarded by them as the abode of Boreas, and the countries beyond them were believed to be mild and lovely; in this belief they were confirmed by the stories about the paradise-like climate in Wallachia. They did not take into consideration the height of the mountains, and conceived that countries were milder, the further they were removed from Boreas: the countries beyond Haemus were, in their opinion, protected against the Scirocco, which was the most troublesome to them. This is the simple and childlike story about the Hyperboreans. Herodotus thinks that, if they really did exist, there must also be Hypernotians, and this would be quite correct, if Notus had been believed, like Boreas, to dwell in a mountain; but the fact is, that Notus was conceived to roam over the endless sandy deserts of Africa which extend to the ends of the earth.