The horizon had vanished or ended into the sky imperceptibly so it could not be distinguished. The captain discussed the matter with them. "I've never seen anything like this before," he said perplexedly. "I've been on a ship that traveled two hundred miles on a milk sea, but never anything like this." "What do you think it is?" asked Davis. "Something on the order of a milk sea?" The captain nodded. "You know a milk sea is caused by a multitude of little animals that color the water milky white. They're phosphorescent at night. This must be something on that order, only these cluster together until the water is made into a jelly. And they have a queer, slimy smell." "They aren't phosphorescent," said Davis. "No, of course not." Nita Morrison had joined the little group. Her father was beside her, looking rather worried. "Well," said Nita anxiously, "what's to be done? How are we going to get the yacht free?" "I'm afraid we aren't," said Davis, smiling. "The telegraphed orders that brought me here told me simply to make an examination and make a report. My plane can't do anything for the yacht, of course." "Then what----" "I'll go back and report," Davis explained, "and they'll send boats to try to get in to you people. There doesn't seem to be any immediate danger, and at worst you can all be taken off by aëroplane, if we can rise again from that jelly mess." Nita wrinkled her small nose. "I know we aren't in danger," she said, "or at least I know it now, but are we going to have to stay here and smell that horrid smell until the government gets ready to rescue us?" The odor of the jellylike animalcules was far from pleasant. It was an unclean scent, as of slime dredged from the bottom of the sea. "Well-l," said Davis thoughtfully, "I dare say we can accommodate two more people. It isn't quite regular, but that's a detail." "But the crew?" Morrison looked inquiringly at the captain of the yacht. "Milk seas always break up, sir," said the captain. "I have no doubt this silver sea will break up as well. We can wait and see, and at worst we have our wireless." "Then it's settled," said Nita joyfully. From sheer gratitude she smiled at Davis. "Always providing we can get aloft again," said Davis. "The propellers of the ship, sir," suggested the captain, "though they can't move the yacht, yet manage to thrash a fair-sized patch of this jelly into liquid." "A good idea," said Davis heartily. "We'll haul the plane around to the stern, and you'll set your engines running." In a very little time this was done. The great propellers of the yacht thrashed mightily, and a narrow patch of open water opened in the silver sea. The seaplane was laboriously hauled around to the stern of the yacht, and the party was lowered on board.