Just a wisp of whitish-grey smoke arose, and beneath it the great rock, with a gapping seam across its top, rolled majestically outward, sending a shower of spray on all sides, and opening to their eager view a black chasm into the heart of the headland.

From a plain of whitish-grey soil, covered with concentric shells as large as a nut, rises a circular embankment with gently-sloping sides, intersected only by a small cleft which serves as an entrance, and which shows, on its edges denuded of vegetation, the loose rapilli of which the embankment is formed.