[Illustration: Fig. 28.--Bird’s-eye view of Santorin during the volcanic eruption of February, 1866. (Lyell.) _a._ Therasia. _b._ The northern entrance, 1068 feet deep. _c._ Thera. _d._ Mount St. Elias, rising 1887 feet above the sea. _e._ Aspronisi. _f._ Little Kaimeni. _g._ New Kaimeni. _h._ Old Kaimeni. _i._ Aphroessa. _k._ George.] The neighborhood of Santorin in the Grecian Archipelago has been noted from very remote times as the theatre of submarine eruptions. This island, which is itself to all appearance the crater of a vast volcano, has the form of a crescent, and, with the aid of two smaller islands which stretch across between the horns of the crescent, encloses an almost circular bay. We learn from Pliny that in the year 186 before Christ, within this bay an island rose up which was called Hiera or the Sacred island. It was twice enlarged during the Christian era, once in 726, and again in 1427, and still exists under the name of Palaia Kaimeni, that is to say, the Old Burnt Island. In 1573 a second island made its appearance, and received the name of the Little Burnt Island, Mikra Kaimeni. In 1707 and 1709, a third island was thrown up, and was distinguished from the other two as Nea Kaimeni, the New Burnt Island. Lastly, in 1866 the hidden volcanic power again became active, and two new vents were formed, called respectively Aphroessa and George. “At the end of January,” writes Sir Charles Lyell, “the sea had been observed in a state of ebullition off the southwest coast, and part of the Channel between New and Old Kaimeni, marked seventy fathoms in the Admiralty chart, had become, on February the eleventh, only twelve fathoms deep. According to M. Julius Schmidt, a gradual rising of the bottom went on until a small island made its appearance called afterward Aphroessa. It seems to have consisted of lava pressed upward and outward almost imperceptibly by steam, which was escaping at every pore through the hissing scoriaceous crust. ‘It could be seen,’ says Commander Lindesay Brine, R. N., ‘through the fissures in the cone that the rocks within were red hot, but it was not till later that an eruption began.’ On February the eleventh the village of Vulcano on the southeast coast, where there had been a partial sinking of the ground, was in great part overwhelmed by the materials cast out from a new vent which opened in that neighborhood, and to which the name of George was given, which finally, according to Schmidt, became about two hundred feet high.