At that instant the whole ship seemed to rise in the air. It left the water and began moving skyward. Right out of the waves the Porpoise was lifted until the big screw was clear of the water and it was churning around in the tunnel without any resistance, racing at top speed now that it had no water to thrust against.
Then the ghost seemed to vanish into thin air, and Jack felt himself falling down the hatchway.
CHAPTER XX
ON A VOLCANIC ISLAND
In an instant the ship was in confusion. The professor, followed by old Andy, Washington, Mark, Bill and Tom, came rushing from their berths, all in their night clothing, to see what the trouble was. They met in a tangled mass, stumbling over Jack at the foot of the steps.
"Is the ship on fire?" called Mrs. Johnson from her cabin.
"I hope not!" called the professor. "But something has happened. Don't be frightened!"
By this time Jack, who had been somewhat stunned, recovered his senses and worked his way out of the mass of bodies.
"The ghost! The ghost!" he cried. "I saw him again!"