Tired out with the night's worry and labors they all slept late the next morning, and it was nearly ten o'clock before breakfast was over. The ship was started on her course once more, and Jack, who was steering, made the engine hum as the submarine scudded along, submerged about fifty feet. "When you have time I would like to talk to you," said Mrs. Johnson to Captain Henderson. "I'm at your service now," replied the inventor. "What are you going to do with Nellie and me?" the lady went on. "Take you to the south pole with us," was the answer, with a smile. "It's very kind of you, and I don't want to put you to any trouble," went on Mrs. Johnson. "But I would like to go back north." "I'd like to oblige you," returned the inventor, "but I hate to turn back now. We are well on our voyage, and I may never get another chance to locate the pole. Don't you want to accompany us? Think of the glorious achievement!" "I'd rather go back north," persisted the lady. "But I wouldn't ask you to turn the ship around. What I was going to suggest was to sail along on the surface for a few days and see if you cannot sight a homeward bound steamer or sailing vessel. Then you could put me and Nellie aboard her." "Of course!" exclaimed Mr. Henderson. "I never thought of that. Though we will be sorry to lose your company, and that of your little girl, I will do anything to oblige you. We will at once go to the surface." He called the necessary order to Jack through a speaking tube which led to the conning tower. In a few minutes the ship shot upward, and emerged from the ocean in a little shower of foam and spray. She lay undulating on the surface, and was just beginning to move forward again, under the influence of the screw, when a dull boom echoed off to the left. Jack looked from the observation windows in the conning tower and saw, about a mile away a big steamer. From her side a white cloud of smoke floated, and then the water splashed about fifty feet from the blunt nose of the submarine. Once more came the boom, the white cloud of smoke and this time the water splashed only twenty-five feet away from the bow of the _Porpoise_. A third time came the sound, and the splash was even nearer. "They're firing on us!" yelled Jack. At his cry the professor ran on deck. He was just in time to see the fourth shot made, and this time the shell dropped into the water just astern of the _Porpoise_ and so close that when it exploded it sent a shower of spray all over the deck. "Here! Stop that!" yelled Mr. Henderson, shaking his fist in the direction of the steamer. "You nearly hit us that time. Do your practicing in some other direction!" "I don't think they can hear you," said Jack. "And besides, I don't believe they are practicing." "Then what in the world are they doing?" "Shooting at us I guess." "Why do they want to shoot at us? We haven't done them any damage."