The growth of coral appears to cease when the worm is no longer exposed to the washing of the sea. Thus, a reef rises in the form of a cauliflower, till its top has gained the level of the highest tides, above which the worm has no power to advance, and the reef of course no longer extends itself upwards. The other parts, in succession, reach the surface, and there stop, forming in time a level field with steep sides all round. The reef, however, continually increases, and being prevented from going higher, extends itself laterally in all directions. But this growth being as rapid at the upper edge as it is lower down, the steepness of the face of the reef is still preserved. These are the circumstances which render coral reefs so dangerous in navigation; for, in the first place, they are seldom seen above the water; and, in the next, their sides are so steep, that a ship's bows may strike against the rock before any change of soundings has given warning of the danger. The island at high water is formed into three parts, which at low water are joined by reefs; the whole being about two and a half or three miles from east to west, and tolerably clear of rocks on the south side; but on the north it is guarded by a semicircle of coral extending upwards of a mile from the shore. On the centre island is only one hut, which, as there was reason to believe it to be the actual abode of the inhabitants, it may be allowable to describe. The walls were sunk under ground, so that only the roof appeared from without, the inside was fifteen feet by six: the walls of neatly squared stones, being two feet high, and the roof in the middle about six or seven high, formed of a ridge pole supported in the centre by a forked stick; the rafters of rough branches were covered with reeds, and thatched over with the leaf of the wild pine, which grows on all the coral islands. The fire-place was at one end on a raised part of the floor, and the other end appeared to be the sleeping place. It was conjectured, that this wretched place could only be meant as a temporary residence of fishermen, whose nets we saw lying about; but the number of water jars and cooking utensils which we found in and about it, gave it the appearance of a fixed habitation. It was almost dark when we quitted the island, and the tide carrying us out of our proper course, we missed the ships and grounded on the reefs near the town; but as the tide was flowing, we easily got off, and by coasting along, soon gained the anchorage. Sunday, 29th of September.--This day is memorable, on account of its being the first on which we were permitted to land.