418 STRAEO. CASAUB. 275. and mines 1 of alum easy to be wrought, hot springs, 2 and craters. [Thermessa] is, as it were, situated between this and Sicily ; it is now designated as Hiera, or sacred to Vulcan ; it is entirely rocky, and desert, and volcanic. In it are three craters, and the flames which issue from the largest are accompanied with burning masses of lava, which have already obstructed a considerable portion of the strait [between Thermessa and the island Lipari] ; repeated observ- ations have led to the belief that the flames of the volcanos, both in this island and at Mount JE^tna, are stimulated by the winds 3 as they rise ; and when the winds are lulled, the flames also subside ; nor is this without reason, for if the winds are both originally produced and kept up by the vapours arising from the sea, those who witness these phenomena will not be surprised, if the fire should be excited in some such way, by the like aliment and circumstances. Polybius tells us that one of the three craters of the island has partly fallen down, while the larger of the two that remain has a lip, the circumference of which is five stadia, and the diameter nearly 50 feet, 4 and its elevation about a stadium from the level of the sea, which may be seen at the base in calm weather ; but if we are to credit this, we may as well attend to what has been reported concerning Empedocles. [Polybius] also says, that " when the south wind is to blow, a thick cloud lies stretched round the island, so that one cannot see even as far as Sicily in the distance; but when there is to be a north wind, the clear flames ascend to a great height above the said crater, and great rumblings are heard ; while for the west wind effects are pro- duced about half way between these two. The other craters are similarly affected, but their exhalations are not so violent. Indeed, it is possible to foretell what wind will blow three days beforehand, from the degree of intensity of the rumbling, and also from the part whence the exhalations, flames, and smoky blazes issue. It is said indeed that some of the in- habitants of the Lipari Islands, at times when there has been so great a calm that no ship could sail out of port, have pre- 1 M. le Comm. de Dolomieu considers it probable that the Liparaeans obtained this alum by the lixiviation of earths exposed to the acido- sulphurous vapours of their volcanos, pp. 77, 78. 2 These hot springs are not much frequented, although they still exist. 3 See Humboldt, Cosm. i. 242. * This is 30 feet in the epitome.
