Harry came aft with a jump and grasped the guy. "Now," he said, "together! Get both hands upon it. Hold the tiller with your elbow." For the next half minute there was a furious struggle, and as the boom went up again Frank felt that they were beaten. His companion, however, hung on desperately, panting hard, and by degrees the boom swung down and back across the boat and the sail flattened out. "Make fast!" cried Harry breathlessly. "I can manage the sheet." He floundered forward to the foot of the mast, and when he came back the spinnaker was drawing steadily and the sloop had changed her mode of progress. She no longer rolled viciously or screwed up to windward as she lifted on a sea, but swayed from side to side with a smooth and easy swing, and Frank could steer her with a touch upon the tiller. In spite of that, steering was ticklish work, for the mainboom and the spinnaker boom went up and came down until they raked the glittering brine alternately, and Frank realized that it would be singularly easy to bring one crashing over upon the other. There was no doubt that the boat was sailing very fast, and he hazarded one swift glance over his shoulder at the canoe. She was surging along astern, hove up with her forward half out of the water, and a seething mass of foam hiding the rest of her. Harry, however, glanced forward somewhat anxiously. "That boom's lifting too much," he said. "One of us ought to sit on it. Do you feel able to steer her?" Frank said that he believed he could manage it. "Well," said Harry, "if you jibe either sail across you'll either pitch me in or break my leg, even if you don't roll the boat over. Sing out the moment you feel her getting too hard upon the helm." Scrambling forward, he crawled out along the spinnaker boom, to which he clung precariously, lifted up high one moment and the next swung down until his feet were just above the foam. Sometimes they splashed in, and Frank, bracing himself until every nerve was strung up, felt horribly uneasy. In spite of that, the wild rush through the glittering water which boiled about the boat was wonderfully exhilarating. She seemed a mass of straining sail which swayed in the moonlight above an insignificant strip of hull half buried in snowy foam. Over her black mainsail peak dim wisps of clouds went streaming by, and from all around there was a tumult of stirring sound--the clamor at the bows, the swish of water as the canoe came charging up to her, and the splash of tumbling seas. Everything ahead, however, was hidden by the sail, and he was wondering where the other boat was when Harry called to him. "Slack the guy a foot or two and let her come up a little. Don't let it get the run of you or you'll pitch me in."