Wearied with their labors and the battle under the waves, the travelers sat up on the deck breathing in the fresh breeze. Then, after a while, supper was made ready and eaten with good appetites.
It was decided hereafter to sail along near the surface at night, and not to submerge the ship deeply save during daylight, when it was easier to distinguish objects under the water.
Following this plan the Porpoise steamed along just awash that night, and the next day was sent down about fifty feet below the surface.
One afternoon, when the travelers were resting, having partaken of a fine meal, the professor went on deck to make some observations, the ship having been raised for that purpose. He came down, somewhat excited.
"Well, we're half way to the pole," he announced.
"How can you tell?" asked Mark.
"Because we have just crossed the equator. We went over the imaginary line three minutes ago."
"I was wondering what made it so warm," said Jack.
"I guess you dreamed it was hotter," spoke the professor. "It has been just as hot as this for the last few days. Crossing the line makes no difference."
"Then we are really in the southern hemisphere now," said Mark.