&2 THE CRATER; his eyes towards the now distant ship, which was appa rently riding at its anchor, in exactly the condition in which it had been left, half an hour before. In that quar ter all seemed right, and Mark led the way to the, mount, with active and eager steps. On reaching the foot of this singular elevation, our ad venturers found it would not be so easy a matter as they had fancied, to ascend it. Unlike the rest of the reef which they had yet seen, it appeared to be composed of a crumbling rock, and this so smooth and perpendicular as to render it extremely difficult to get up. A place was found at length, however, and by lending each other a hand, Mark and Bob finally got on the summit. Here a surprise was ready for them, that drew an exclamation from each, the instant the sight broke upon him. Instead of finding an elevated bit of table-rock, as had been expected, a cir cular cavity existed within, that Mark at once recognised to be the extinct crater of a volcano ! After the first asto nishment was over, Mark made a close examination of the place. The mound, or barrier of lava and scoria3 that composed the outer wall of this crater, was almost mathematically circular. Its inner precipice was in most places absolutely perpendicular, though overhanging in a few; there being but two or three spots where an active man could descend in safety. The area within might contain a hundred acres, while the wall preserved a very even height of about sixty feet, falling a little below this at the leeward side, where there existed one narrow hole, or passage, on a level with the bottom of the crater ; a sort of gateway, by which to enter and quit the cavity. This passage had no doubt been formed by the exit of lava, which centuries ago had doubtless broken through at this point, and contributed to form the visible reef beyond. The height of this hole was some twenty feet, having an arch above it, and its width may have been thirty. When Mark got to it, which he did by descending the wall of the crater, not without risk to his neck, he found the surface of the crater very even and unbroken, with the exception of its having a slight descent from its eastern to its western side ; or from the side opposite to the outlet, or gateway, to the gateway
