It was a wonderful sight. There lay the island, plain to see, and no one but a trained observer could have detected that it was a sham. But Tari and Broncho were right. Many a mile had the cowpuncher ridden in chase of just such a lifelike image on the prairie without getting any nearer. "These here mirages is just a deadfall, an' many a poor cowman has panned out through trailin' after them," observed Broncho. "Well, the island that mirage reflects is somewhere down under the horizon," said Jack. "Just take its bearings, one of you, and we'll shape our course for it directly the wind condescends to blow." "It's north-a-half-west," said Jim, after a look at the compass. All that long afternoon, whilst they drifted helplessly, the fairy island hung over the horizon in the north. Soon after darkness had fallen Jack startled the whole boat's crew by saying very quietly, "Boys, it's my watch on deck now. I've got my sight back." There was a wild, hoarse cheer, a buzz of congratulations, and night set in. CHAPTER VI "THE ATOLL" During the night the south-east trades came upon them in a squall, and the whaleboat was soon bowling along merrily. In a short while they found themselves in the midst of a choppy, foam-flecked sea, making good headway before the gradually strengthening breeze. As daylight crept over the east, Jack, with a horrible sinking feeling of dismay, felt his returned eyesight gradually fail again. As the deep indigo of the night gave way before the rosy beams of the morning sun and the moon lost its glitter, Jack saw a mist of grey slowly spreading before him; then, as the light of day increased, the grey merged into a black, which grew darker and darker, until the rover felt as if he was being pressed down by an awful pall of ink, pierced by tiny shafts, glinting flickers, and hovering waves of flashing, scintillating light, which splashed through the black curtain for all the world like the Northern Lights. Great was the distress of his companions on hearing of this return of the evil. Jack took his misfortune very quietly, and stretched himself in the bottom of the boat with a great show of fortitude and resignation. "Keep a look-out for the island," he murmured, and then lay silent with closed eyelids, which he found afforded him some relief from the shafts of light which leaked in through the black shroud of his blindness and burnt his aching eyeballs. A heavy feeling of depression weighed down upon the boat's crew, and Broncho's many attempts to break it only served to increase it. Jim felt cowed and frightened; Tari, always of a singularly silent disposition, remained mute in the bows, and whilst Jack tried hard to respond to Broncho's sallies, his tortured brain refused to follow the thread of the discourse, and he found himself answering at random and listening without hearing.