In Holy Island, near the ruins of the convent (in the dungeons of which romance has decided the fate of Constance Beverley), was a small fortress of invalid soldiers. One of them once conducted a visitor to a steep rock, under which, he said, there must be a profound cavern, as the sound of a bell was distinctly heard every night at twelve o’clock, deep in the bowels of the earth. The traveller soon discovered that the mysterious sound had _never been heard_ by the oldest inmates, _until_ the poem of “Marmion” appeared, in which the condemnation and the death of Constance in the dungeons of the cathedral are so forcibly described. This is, however, a _metaphysical_ source of mystery. In volcanic regions, as in that of the Solfatara, near Naples, these strange and subterranean sounds are not unfrequently heard; and in the rocky and caverned coasts of our own island also, where dwell the unlettered and the superstitious, by whose wild and romantic fancy these noises are readily magnified into the supernatural. Camden, in his “Britannia,” informs us,—“In a rock in the island of Barry, in Glamorganshire, there is a narrow chink, or cleft, to which if you put your ear you shall perceive all such sorts of noises as you may fancy smiths at work under ground, strokes of hammers, blowing of bellows, grinding of tools.” At Worm’s Head, in the peninsula of Gower in Glamorganshire, these sounds are, even now, often heard; and it requires but a moderate stretch of imagination to create all this cyclopean imagery, when the sea is rolling in cavities under our feet, and the tone of its voice is magnified by confinement and repercussion. From some such source probably sprung the fable of “the Syrens,” two solitary maidens, who, by their dulcet voices, so enchanted the navigators who sailed by their rocks, that they forgot home and the purpose of their voyage, and died of starvation. Ulysses, instructed by his mother Circe, broke the spell, and the ladies threw themselves into the sea with vexation. This fable, like many of the classic mysteries, may be thus topographically explained. In the grand duchy of Baden, near Friburg, is a very curious example of an Æolian lyre, constructed, as the traditions of the mountains will have it, by the very _genius loci_ himself. In a romantic chasm of these mountains, most melodious sounds are sometimes heard from the top of fir-trees overhanging a waterfall. The current of air, ascending and descending through the chasm, receives a counter impulse from an abrupt angle of the rock, and, acting on the tops of the string-like branches of the trees, produces the soft tones of the Æolian harp, the effect of which is much enhanced by the gushing of the waterfall. There may be in these natural sounds the source of many fables of the ancients: the moaning of the wind among the branches of a pine-grove might be the wailing of a hamadryad.