“Oh, it was a rat that took your stuff,” Mr. Henderson said. “I guess there are some pretty big ones on the ship. Get some more food and go to sleep.”
Mark felt it best to obey, though he was by no means satisfied with the professor’s explanation. He listened intently to see if any more noises came from the storeroom, but none did, and he went to bed.
Several times after that Mark tried the experiment of leaving food about. On each occasion it was taken.
“It looks as if the ship was haunted,” he said. “Of course I know it isn’t, but it’s very queer. They must be strange rats that can get food from shelves when there is only the smooth side of the ship to climb up,” for on some occasions Mark had tried the experiment of putting the food as nearly out of reach as possible.
It took several nights to learn all this, and, as he did not want to take any one into his confidence, he had to work in secret. But, with all his efforts he learned nothing, save that there was something odd about the ship that he could not fathom.
At first he believed the professor had some strange animal concealed in the storeroom, but he dismissed this idea almost as soon as he thought of it. For what could the scientist want with an animal when they were going to the interior of the earth? That some beast had slipped aboard was out of the question. Mark was much puzzled, but finally, deciding the matter did not concern him a great deal, gave up trying to solve the mystery, at least for a time.
The ship was now in the neighborhood of the equator and the climate had become much warmer. So hot indeed were some nights that they slept out on deck, with the Mermaid flying through the air at a moderate pace, for it was deemed best not to go at any great speed after dark.
One night the professor, after consulting various charts and maps, and making calculations which covered several sheets of paper announced:
“We should sight the mysterious island to-morrow.”
“That’s good news!” exclaimed Jack. “I’m anxious to see what’s below inside of that big hole.”