All at once the tilting motion ceased, the _Peacemaker's_ stern tanks were filled, and she floated on an even keel. Leaving the care of the wheel to Ensign Hargreaves, who, as we know, was familiar with the usual type of submarine, Mr. Barr came into the cabin. "Well, boys, what do you think of it?" he asked with a smile. "It's g-g-great," rejoined Tubby, with a notable lack of his usual assurance. "And now I suppose you'd like to see what the bottom of the sea looks like. We are down some two hundred fathoms and about fifty miles off the coast. Should you care to see how things look down here?" "How will that be possible?" asked Merritt. By way of reply Mr. Barr went to the starboard wall of the cabin and pulled a lever connecting with a worm gear. As he did so, a great section of the _Peacemaker's_ steel side drew back and revealed a plate glass window set between the inner and outer "skins" of the craft. The boys crowded round the window and peered out eagerly. But to their disappointment they could see no more of their surroundings than if they had been looking out of a train window on a dark night. It was as black as a wolfs mouth at those unknown depths. "Why, we can't see anything," came a disgruntled chorus. "Wait a minute," smiled the inventor. [Illustration: THE BOYS CROWDED ROUND THE WINDOW AND PEERED OUT EAGERLY.] Pressing a button, he extinguished the cabin lights. Then he opened a sort of closet in the wall alongside the window and swung out a powerful, though small, searchlight attached to an adaptable arm in the same manner as a desk telephone. There was a clicking sound, and a flood of white light pierced the blackness outside. The boys broke into delighted exclamations as the powerful rays revealed all sorts of fish, many of odd shapes and colors, attracted by the light. Suddenly a dark, shadowy form swung into view. Instantly the other fish vanished, and the boys saw that the newcomer was a large shark swimming leisurely along. No doubt he wondered who the strangers in his deep sea abode could be, for he swam up close to the window, causing the boys to shrink back. They quite forgot that between them and the tiger of the deep was a solid plate of glass as strong almost as steel. The shark gazed at the window for an instant and then vanished. With its disappearance, the other fish reappeared and kept the submarine company, for all the world like sea gulls circling round a ship entering port. "I wonder if they are hungry and want us to throw some food out to them," said Tubby stolidly, as he gazed at the finny tribes darting here and there in the searchlight's rays. "Gracious, do you think that the fish have the same appetite as you have?" laughed Merritt. "Just the same, some of those fellows would taste all right broiled," declared the stout youth, at which there was a general laugh. After an hour spent in this manner the searchlight was switched off and the panels slid back into place.