"Far upon the unknown deep, 'Mid the billows circling round, Where the tireless sea-birds sweep; Outward bound. Nothing but a speck we seem, In the waste of waters round, Floating, floating like a dream; Outward bound." Frank was less sentimental, and repeated these lines: "Two things break the monotony Of a great ocean trip: Sometimes, alas! you ship a sea, And sometimes see a ship." Then they called upon the Doctor for a contribution, original or selected, with this result: "The praises of the ocean grand, 'Tis very well to sing on land. 'Tis very fine to hear them carolled By Thomas Campbell or Childe Harold; But sad, indeed, to see that ocean From east to west in wild commotion." [Illustration: THE WIND RISING.] The wind had been freshening since noon, and the rolling motion of the ship was not altogether agreeable to the inexperienced boys. They were about to have their first acquaintance with sea-sickness; and though they held on manfully and remained on deck through the afternoon, the ocean proved too much for them, and they had no appetite for dinner or supper. But their malady did not last long, and by the next morning they were as merry as ever, and laughed over the event. They asked the Doctor to explain the cause of their trouble, but he shook his head, and said the whole thing was a great puzzle. "Sea-sickness is a mystery," said he, "and the more you study it, the less you seem to understand it. Some persons are never disturbed by the motion of a ship, no matter how violent it may be, while others cannot endure the slightest rocking. Most of the sufferers recover in a short time, and after two or three days at sea are as well as ever, and continue so. On the other hand, there are some who never outlive its effects, and though their voyage may last a year or more, they are no better sailors at the end than at the beginning. "I knew a young man," he continued, "who entered the Naval Academy, and graduated. When he was appointed to service on board a ship, he found himself perpetually sick on the water; after an experience of two years, and finding no improvement, he resigned. Such occurrences are by no means rare. I once travelled with a gentleman who was a splendid sailor in fine weather; but when it became rough, he was all wrong, and went to bed." "Were you ever sea-sick, Doctor?" queried Frank. "Never," was the reply, "and I had a funny incident growing out of this fact on my first voyage. We were going out of New York harbor, and I made the acquaintance of the man who was to share my room. As he looked me over, he asked me if I had ever been to sea. "I told him I never had, and then he remarked that I was certain to be sea-sick, he could see it in my face. He said he was an old traveller, and rarely suffered, and then he gave me some advice as to what I should do when I began to feel badly. I thanked him and went on deck.