Considering that our present (it is true, very limited) geological knowledge of the mountainous parts of North Africa does not make us acquainted with any trace of volcanic eruptions within historic times, it is very remarkable to find among the ancients so many indications of a belief in the existence of this class of phenomena, in the Western Atlas, and in the neighbouring west coast of the continent. The streams of fire, so often mentioned in Hanno’s ship-journal, may indeed have only been strips of burning grass, or signal fires kindled by the wild inhabitants of the coasts to give to each other notice of the danger threatened by the appearance of the hostile vessels. The lofty flame-enlightened summit of the “chariot of the gods” (θεῶν ὅχημα), may recall obscurely the Peak of Teneriffe; but farther on Hanno describes a singular conformation of ground. He finds in the Gulf near the Western Horn, a large island, and in it a salt lake which again contains a smaller island. South of the bay of the Gorilla Apes, the same conformation is repeated. Is this a description of coral productions, of “lagoon islands, (Atolls)” or volcanic “crater lakes” in the middle of which a cone has been upheaved? The Triton lake was not in the neighbourhood of the lesser Syrtis, but near the Atlantic coast. (Asie Cent. T. i. p. 179.) The lake disappeared in consequence of earthquakes which were accompanied by great outbursts of fire. Diodorus (Lib. iii. 53, 55) says expressly, πυρὸς ἐκφυσήματα μεγάλα. But the most wonderful conformation is ascribed to the “hollow Atlas” in a passage hitherto little noticed, occurring in one of the philosophic Dialexes of Maximus Tyrius. This Platonic philosopher lived in Rome, under Commodus. The situation of his Atlas is “on the continent, where the Western Lybians inhabit a projecting peninsula. The mountain has in it towards the sea a semicircular deep abyss.” The precipices are so steep that they cannot be descended; the abyss below is filled with trees, and “one looks down upon their summits, and on the fruits which they bear, as if one was looking into a well.” (Maximus Tyrius, viii., 7, ed. Markland.) The description is so graphic and so individually marked, that it doubtless conveys the recollections impressed by a real prospect. [23] p. 11.--“_The Mountains of the Moon, Djebel al Komr._”