The rich blue of the harbour is separated from the purplish indigo of the great ocean by a submarine rainbow of indescribable loveliness. This is caused by the coral-reef, which produces a gleaming ray as if from a hidden prism. The patches of coral, sea-weed, and sometimes white sand, lying at irregular depths, beneath a shallow covering of the most crystalline emerald-green water, produce every shade of aqua marine, mauve, sienna, and orange, all marvellously blended. The shades are continually varying with the ebb and flow of the tide, which at high water covers the reef to the depth of several feet, while at low tide patches here and there stand high and dry, or are covered by only a few inches of water; treacherous ground, however, on which to land, as the sharp coral spikes break under the feet, cutting the thickest leather, and perhaps landing you in a hole several feet in depth, with still sharper coral down below. The highest edge of the reef lies towards the ocean, and a line of dazzling white surf marks where the great green breakers wage their ceaseless warfare on the barrier; but the passage through the reef is plainly marked by a break in the white line, and a broad roadway of deep blue connecting the inner waters with the great deep; and this, again, passes in gradual gradations of colour, from the intense blue of the harbour to the glittering green of the shallow water on the inner side of the reef. Altogether it is most fascinating. The scene is loveliest at noon, when the sun is right overhead, and lights up the colours beneath the water on the coral caves. Also you must be some way up the hill to get a good view of the reef. Of the radiant opal tints which overspread sea, isles, and sky, at the outgoings of morning and evening, I need not tell you; our own northern shores supply sunrise and sunset colours more vivid than we often see in the tropics. This afternoon has been one of unmitigated enjoyment spent on the reef, where for so many days I have enviously watched the Fijian girls disporting themselves at low tide, and bringing back baskets full of all sort of curious fish, many of them literally rainbow-coloured. Some are most gorgeous, and are called parrot-fish. They have large bony beaks, rather than ordinary mouths, to enable them to feed on the coral, which at certain seasons are said to be “in flower,” and very unwholesome; so we always eat these radiant fish with some qualms, and not without good reason, for some people have had the ill-luck to get poisoned, and have suffered severely in consequence.