They crawled out again shortly afterward and found the seas getting longer and bigger. Once or twice a blur of something went by that might have been the end of an island, and Mr. Oliver changed his course a little, but after that the dim, green water stretched away before them empty and only broken by smears of snowy froth, and the sloop drove on before the combers which came up out of the haze astern of her in long succession. It was toward noon, and Mr. Oliver had gone into the cabin to get dinner ready, leaving Harry at the helm, when, glancing around, Frank saw an indistinct mass of something break out of the mist. It grew into the shadowy shape of a steamer while he watched it. "There's a big vessel close by," he said, touching his companion's arm. Harry glanced over his shoulder. "Sure," he nodded. "What's more, she's coming right along our track. Get in some mainsheet while I luff her." He changed the sloop's course a trifle, but in the meanwhile the steamer was growing in size and distinctness with a marvelous rapidity. Her great bow seemed to be rising out of the water like a headland, over which Frank could just see the tiers of white deckhouses, one mast, and the tall smokestack. Then he glanced forward at the sloop's wet deck and the low strip of her double-reefed mainsail, looking very small among the tumbling seas, and it occurred to him that it would probably be difficult for the steamer's lookout to see them. He felt rather anxious when he glanced back astern. "She still seems to be coming right down on us," he said. Harry called his father, who hurried out and glanced at the vessel. "Shall we get up and yell?" the boy asked. "No," said Mr. Oliver curtly, "they couldn't hear you to windward. Let her come up farther." Frank helped drag some more mainsheet and then looked around again with a very unpleasant thrill of apprehension. The black bow seemed almost above them, and the sea leaped against a wall of plates as the great mass of iron swung slowly out of it and sank down again. Then from somewhere beside the smokestack a streak of white steam blew out and a great reverberatory roar came hurtling about them. Mr. Oliver's anxious face relaxed. "They've seen us," he said. "Her helm's going over." The bow drew out and lengthened into an increasing strip of side. Another mast became visible, with a double row of white deckhouses and a tier of boats between. Here and there a cluster of diminutive figures showed up among them, and then the great ship sped by with the whole of her size revealed. The sloop plunged madly on her screw-torn wake, but in another minute or two she had drawn away and was melting into the haze again. "A big boat," said Mr. Oliver. "She was very close to us. You had better keep your eyes open while I get dinner."