Mrs. Johnson was much interested in the Porpoise and Professor Henderson showed her all about the craft. Though the quarters were rather cramped, a small cabin was fitted up for the lady and her daughter.
"We will travel a bit under the water so you can get used to it," said the captain after a tour of the ship had been made. The tanks were filled, and the Porpoise sank beneath the waves. At first Mrs. Johnson was much frightened, and Nellie cried. But when they saw how skillfully the ship was managed, and how easy it was to rise again, they lost their fears.
For several days the voyage was continued. Mrs. Johnson and Nellie remained aboard as there was no place to land them, and they said they wished to stay until they met some ship sailing north.
One day, just at dusk, when the Porpoise, after a long run under the water had come to the surface, the professor, came up on deck to take a look around. Washington and Andy accompanied him.
"Looks like land, off there to the left," remarked the old hunter.
"Get the glasses, Washington," said Mr. Henderson. "It may be a ship."
He took a long and careful look through the binoculars.
"It's some sort of land," he announced. "We'll go over in the morning and see what it is. Probably it's an island, for there's no main land in these parts. We are in the middle of the southern Atlantic now."
The next morning, after breakfast, the Porpoise was headed toward the dark spot on the surface of the water that the professor had gazed at the evening before. As they came nearer it was seen that the place was a large island.
"But it's a mighty queer one," spoke Mr. Henderson. "It looks more like a big volcano than anything else."