There are several deep entrances through this reef, and inside it there is hood anchorage in all weathers.

The land rises gradually to a moderate height, and numerous small streams descend on all sides.

The mere existence of these streams would prove that the island was not entirely coralline, as in that case all the water would sink through the porous rock as it does at Manowolko and Matabello; but we have more positive proof in the pebbles and stones of their beds, which exhibit a variety of stratified crystalline rocks.

About a hundred yards from the beach rises a wall of coral rock, ten or twenty feet high, above which is an undulating surface of rugged coral, which slopes downward towards the interior, and then after a slight ascent is bounded by a second wall of coral.

Similar walls occur higher up, and coral is found on the highest part of the island.
This peculiar structure teaches us that before the coral was formed land existed in this spot; that this land sunk gradually beneath the waters, but with intervals of rest, during which encircling reef's were formed around it at different elevations; that it then rose to above its present elevation, and is now again sinking.