Then away and away through the burning sunshine the yacht glided, with the sea glistening like damascened steel frosted with silver, till the mountains above the coaling port grew distant; and away over the burning Afric sands there was a wondrous orange glow which deepened into fire, vermilion, crimson, purple, and gold of the most refulgent hues, and soon after it was night. It seemed to Jack as he stood gazing forward that they were gliding on between two vast purply black basins studded with stars, which were larger and brighter than any he had seen before, while deeper and deeper in the wondrous depths there were more and more, till the farthest off seemed like clusters and patches of frosted gold. There was not a breath of air when they went on deck after dinner, and with the exception of the throbbing and humming of the engine and propeller, and soft whish of the sea as it was divided and swept along the sides, all was wonderfully still. But the silence was soon after broken by a sharp call from somewhere forward, a clear musical voice rang out, and then, sounding very sweet and melodious on the soft air, the men began glee-singing, showing that they had good voices among them and no little knowledge of singing in parts. They were simple old glees and madrigals, and no doubt the surroundings helped, but Jack sat listening and thinking he had never heard music so sweet and beautiful before. "Why, captain," said Sir John, "this is a surprise." "Is it, sir? Hope you don't mind." "Mind?" echoed Sir John and the doctor in a breath. "Bartlett's fond of a bit of music, and he has a good voice too, but he is so precious modest you can't get him to sing alone; he's singing with the men though now. He trains them a bit when we're not busy, and they like it. Nothing pleases men like them more than singing in chorus; you see, they're most of them Cornish and Devon lads, and they take naturally to it. Many's the time I've heard the fishermen going out on calm evenings to their fishing-ground singing away in parts, so that you'd think that they had been well taught, and perhaps not one of them knowing a note of music." The glee-singing went on for about an hour, and ceased as suddenly as it had begun. Then the watch was set, and after standing leaning over the bows gazing at the glittering stars reflected in the deep water, and seeing the phosphorescent creatures add to the lustre as they were disturbed by the yacht's prow, or some large fish darting away, Jack heaved a deep sigh and turned to go aft to the cabin. "Unhappy, my boy?" said a voice at his elbow, which made the lad start and remain silent for a few moments, utterly unable to give expression to his feelings, before he said softly-- "No, father, not unhappy, but low-spirited and sad." "Sad, my boy?" said Sir John.