The consternation of the little party when they thus beheld the rapid drowning of the world below them, and saw no possibility of escape for themselves if the water continued to advance, as it evidently would do, cannot be depicted. Some of them were driven insane, and were with difficulty prevented by those who retained their senses from throwing themselves into the flood. Pludder was the only one who maintained a command over his nerves, although he now at last _believed in the nebula_. He recognized that there was no other possible explanation of the flood than that which Cosmo Versál had offered long before it began. In his secret heart he had no expectation of ultimate escape, yet he was strong enough to continue to encourage his companions with hopes which he could not himself entertain. When, after nightfall on the tenth day, the water began to lap the lower parts of the aero, he was on the point of persuading the party to clamber up the rocks in search of the shelter above, but as he stepped out of the door of the cabin to reconnoiter the way, with the aid of the searchlight which he had turned up along the ridge, he was astonished to find the rain rapidly diminishing in force; and a few minutes later it ceased entirely, and the stars shone out. The sudden cessation of the roar upon the roof brought everybody to their feet, and before Professor Pludder could communicate the good news all were out under the sky, rejoicing and offering thanks for their deliverance. The women were especially affected. They wept in one another's arms, or convulsively clasped their children to their breasts. At length the President found his voice. "What has happened?" he asked. Professor Pludder, with the new light that had come to him, was as ready with an explanation as Cosmo Versál himself had been under similar circumstances. "We must have run out of the nebula." "The nebula!" returned Mr. Samson in surprise. "Has there been a nebula, then?" "Without question," was the professor's answer. "Nothing but an encounter with a watery nebula could have had such a result." "But you always said----" began the President. "Yes," Pludder broke in, "but one may be in error sometimes." "Then, Cosmo Versál----" "Let us not discuss Cosmo Versál," exclaimed Professor Pludder, with a return of his old dictatorial manner. CHAPTER XV PROFESSOR PLUDDER'S DEVICE Morning dawned brilliantly on Mount Mitchell and revealed to the astonished eyes of the watchers an endless expanse of water, gleaming and sparkling in the morning sunlight. It was a spectacle at once beautiful and fearful, and calculated to make their hearts sink with pity no less than with terror. But for a time they were distracted from the awful thoughts which such a sight must inspire by anxiety concerning themselves. They could not drive away the fear that, at any moment, the awful clouds might return and the terrible downpour be resumed.