Once in the dark ages before the great exilings an appalling disaster had occurred which ploughed deep into the consciousness of the people the necessity for the development of this earth science. Their central city stood upon a great plateau up the slope of Lilaroma. Within recorded memory there had been no great outburst from the mountain; and the inhabitants travelled fearlessly up to its rim and down the bowl of its crater. At times there had been slight spittings of ashes and once or twice a new fumarole or hot spring or even lava fountain had opened at some point on the mountain slope; but these were all at a distance from the bustling, luxurious city; and most of them had awakened slight notice. The volcano indeed had been practically quiescent since the great migration from the Antarctic regions and the sealing of the archipelago by the circle of fog. The citizens were keeping one of their annual feasts, and were lapped in luxurious ease and pleasure. They had been exhilarated by a long period of prosperity and a recent victory over the savage clan that inhabited one of the adjacent islands. The country people and a number of hermits living in lonely parts of Limanora had been alarmed by various premonitory symptoms, sultry clouds turbaning the head of Lilaroma, tremors in the earth more and more threateningly repeated, great and unaccountable disturbances in the sea, and a hot, heavy, brooding atmosphere around the whole island. Some of them came to the city and warned the revellers to be prepared for some catastrophe; but they were waved aside as dreamers, mere superstitious disturbers of life and its traffic. Half the city was gathered together in the central market-place to see a great spectacle, when the earth shook beneath them. They fell on their faces and cried to their gods; but it was in vain. The market stood upon a plateau high above the rest of the city, overlooking the ocean. Like a cap this platform was blown into the air, and all the pleasure-seekers vanished like smoke. Out on the sea and here and there on the land a rain of dust fell mingled with minute pieces of human flesh; but never was any one of the gathered thousands found; and as if to obliterate the traces of her ghastly work, the mountain sent down a broad stream of lava, which filled up the gulf where the market-place had been, and sealed up the dust-buried city, preserving it for after-ages like a fly in amber. Those who escaped destruction fled, some to distant parts of Limanora, some to other islands; but all were buried for centuries in grovelling superstition. It was out of the hermits and the country people that a new nation was built up, which set itself as a first duty to establish Leomarie, that it should not be taken unawares by any repetition of this great catastrophe. Nor has it ever recurred, although there have been many premonitory symptoms. The lava wells or vents eased the labours of the internal fires and saved the island.