Some of them are planted with vineyards to their summits.(571) Thus the volcanic soil is still as favourable to the cultivation of the vine as it was in antiquity. The relation between the two was noted by the ancients. Strabo compares the vines of the Burnt Land with the vineyards of Catania fertilized by the ashes of Mount Etna; and he tells us that some ingenious persons explained the fire-born Dionysus as a myth of the grapes fostered by volcanic agency.(572) § 5. The Earthquake God. (M145) But the inhabitants of these regions were reminded of the slumbering fires by other and less agreeable tokens than the generous juice of their grapes. For not the Burnt Land only but the country to the south, including the whole valley of the Maeander, was subject to frequent and violent shocks of earthquake. The soil was loose, friable, and full of salts, the ground hollow, undermined by fire and water. In particular the city of Philadelphia was a great centre of disturbance. The shocks there, we are told, were continuous. The houses rocked, the walls cracked and gaped; the few inhabitants were kept busy repairing the breaches or buttressing and propping the edifices which threatened to tumble about their ears. Most of the citizens, indeed, had the prudence to dwell dispersed on their farms. It was a marvel, says Strabo, that such a city should have any inhabitants at all, and a still greater marvel that it should ever have been built.(573) However, by a wise dispensation of Providence, the earthquakes which shook the foundations of their houses only strengthened those of their faith. The people of Apameia, whose town was repeatedly devastated, paid their devotions with great fervour to Poseidon, the earthquake god.(574) Again, the island of Santorin, in the Greek Archipelago, has been for thousands of years a great theatre of volcanic activity. On one occasion the waters of the bay boiled and flamed for four days, and an island composed of red-hot matter rose gradually, as if hoisted by machinery, above the waves. It happened that the sovereignty of the seas was then with the Rhodians, those merchant-princes whose prudent policy, strict but benevolent oligarchy, and beautiful island-city, rich with accumulated treasures of native art, rendered them in a sense the Venetians of the ancient world. So when the ebullition and heat of the eruption had subsided, their sea-captains landed in the new island, and founded a sanctuary of Poseidon the Establisher or Securer,(575) a complimentary epithet often bestowed on him as a hint not to shake the earth more than he could conveniently help.(576) In many places people sacrificed to Poseidon the Establisher, in the hope that he would be as good as his name and not bring down their houses on their heads.(577)