incredible density like that of gnats or hiving bees; the mass flashed white and black, and heaved and quivered, and the screaming of the creatures rose over the voice of the surf in a shrill clattering whirr.  As you descend some inland valley a not dissimilar sound announces the nearness of a mill and pouring river.  Some stragglers, as I said, came to meet our approach; a few still hung about the ship as we departed.  The crying died away, the last pair of wings was left behind, and once more the low shores of Kauehi streamed past our eyes in silence like a picture.  I supposed at the time that the birds lived, like ants or citizens, concentred where we saw them.  I have been told since (I know not if correctly) that the whole isle, or much of it, is similarly peopled; and that the effervescence at a single spot would be the mark of a boat’s crew of egg-hunters from one of the neighbouring inhabited atolls.  So that here at Kauehi, as the day before at Taiaro, the Casco sailed by under the fire of unsuspected eyes.  And one thing is surely true, that even on these ribbons of land an army might lie hid and no passing mariner divine its presence.

CHAPTER II—­FAKARAVA:  AN ATOLL AT HAND

By a little before noon we were running down the coast of our destination, Fakarava:  the air very light, the sea near smooth; though still we were accompanied by a continuous murmur from the beach, like the sound of a distant train.  The isle is of a huge longitude, the enclosed lagoon thirty miles by ten or twelve, and the coral tow-path, which they call the land, some eighty or ninety miles by (possibly) one furlong.  That part by which we sailed was all raised; the underwood excellently green, the topping wood of coco-palms continuous—­a mark, if I had known it, of man’s intervention.  For once more, and once more unconsciously, we were within hail of fellow-creatures, and that vacant beach was but a pistol-shot from the capital city of the archipelago.  But the life of an atoll, unless it be enclosed, passes wholly on the shores of the lagoon; it is there the villages are seated, there the canoes ply and are drawn up; and the beach of the ocean is a place accursed and deserted, the fit scene only for wizardry and shipwreck, and in the native belief a haunting ground of murderous spectres.

By and by we might perceive a breach in the low barrier; the woods ceased; a glittering point ran into the sea, tipped with an emerald shoal the mark of entrance.  As we drew near we met a little run of sea—­the private sea of the lagoon having there its origin and end, and here, in the jaws of the gateway, trying vain conclusions with the more majestic heave of the Pacific.  The Casco scarce avowed a shock; but there are times and circumstances when these harbour mouths of inland basins vomit floods, deflecting, burying, and dismasting ships.  For, conceive a lagoon perfectly sealed but in the one point, and that of merely navigable width; conceive the tide and wind to have heaped for hours together in that coral fold a superfluity of waters, and the tide to change and the wind fall—­ the open sluice of some great reservoirs at home will give an image of the unstemmable effluxion.