text:  Imagine an immense cavern all pure azure--as if God had made a tent there with some residue of the firmament; a surface of water so limpid so transparent that you seem to float on air: above you the pendant stalactites huge and fantastical reversed pyramids and pinnacles: below you a sand of gold mingled with marine vegetation; and around the margin of cave where it is bathed by the water the coral shooting out its capricious and glittering branches