Breakfast was served and hurriedly eaten, for the excitement was telling on every one. After the meal had been cleared away they all sat in the darkened cabin looking out at the water as it slipped past the glass windows. Big and little fish swam up and peered into the bull's-eyes and then darted away. "That's sort of queer," remarked Jack a little later. "What is?" asked Mark, who was sitting near his chum. "All the fish seem to have suddenly disappeared," replied Jack. "There were hundreds a little while ago, and now I haven't seen one looking in the windows for some time." "Perhaps there's a big fish on their trail," observed Mark. "That's what makes 'em take to the deep sea weed." "Maybe so," replied Jack. A little later Professor Henderson entered the room. He went over, looked at the thermometer, and then called to Washington: "Have you got the heat turned on?" "No, sah! I ain't done truned on no superheated vapor into de radiators," replied the colored man. "I were jest thinkin' dat we'd hit de south pole by de feel of it." "It is getting strangely warm," admitted Mr. Henderson. "Ain't that what you expected at the south pole?" asked Andy. "I thought it was hot at the south pole and cold at the north." "That's what lots of people imagine," said the professor, "but except for the open sea, which I have proved does exist, I guess it's just as cold at the south as at the north, especially in the winter. We have struck the summer season." "And a mighty warm one at that," observed Jack. "Whew! I've got to take off my coat." Indeed it was getting uncomfortably warm in the ship, and the adventurers who had dressed in thick clothing to guard against the rigors of the icy climate, soon had to lay aside many of their garments. "No wonder!" exclaimed Mr. Henderson, as he looked at a thermometer. "It is eighty degrees in here!" "Worse than workin' in a hay field," observed Bill, as he wiped the beads of perspiration from his forehead. "Let us see what sort of water we are traveling through," suggested the professor, as he again turned off the lights in the cabin so that a view could be had from the bull's-eyes. Wondering what would meet their gaze the adventurers peered out of the small circular windows. At first they could hardly believe their eyes. There, right before them, the sea was bubbling as if it was an immense tea kettle. Steam formed on the glass, and big clouds of vapor could be seen. The atmosphere of the cabin became almost unbearable. "We are in the midst of a boiling hot ocean!" cried the professor. "Are we sailing through hot water?" asked Andy. "I should say so, from the feel of it," answered Mr. Henderson. "Put your hand on the side of the cabin." Andy laid his fingers against the steel plates. He drew back. "I burned myself!" he exclaimed. "What are we to do?" cried Jack.