"It is in less than two hundred feet of water; see, the air bubbles are still coming up, although it went down fully fifteen minutes ago." The steamer slowed down as it came abreast, and the passengers leaned over the side in intense excitement, watching the signs which indicated the death of another sea terror. Even while they were watching one immense boiling zone appeared and settled down, indicating that another air tank had given way, or that the pressure of the sea water had forced the air from one of the innumerable pockets in the interior of the submarine. Four bells indicated a resumption of the journey. The great funnels began to pour forth smoke in immense volumes, and the ship fairly shook with the revolutions of the twin screws. "So we are going directly south," said Ralph, who had just examined the compass, and started for the stairway. "There will be no let-up now," remarked the captain. Every one understood that forced draught would now be resorted to, both to avoid the likelihood of being torpedoed, and also to enable the ship to reach port at the earliest possible moment. The _St. Duneen_, although a twin-screw vessel, was not of more than 5,000 tons burden, having been built as a mail carrier for distant ports, in which speed was regarded as the important element in her construction. As the commander remarked to the captain, after the latter reached the bridge, he felt sure that the speed alone, which he was able to make in an emergency, would baffle any attempt to reach his hull. It seemed so, for the vessel fairly skimmed the surface of the water, and left a trail which could be marked for miles. Every one felt happy, and there was a feeling of security aboard that was shared by every one. Luncheon was announced, and the boys were descending the stairway leading to the cabin, when they felt a peculiar sensation. They were thrown down the steps, taking with them several women and children, who were alongside. No sooner had they landed at the bottom, when the most terrific crash was heard. "Submarine!" shrieked a voice. The sensation of the oscillating movement of the vessel was a sickening one. The dining room was half-filled with women, children and men. "To your cabins at once; life belts as quickly as possible!" shouted an officer. "The men must aid the women and children. Do not become excited." This warning had a marked effect; it restored the confidence which had been so rudely shocked. Ralph and Alfred sprang for the closets where the life preservers were kept, and threw them out on the floor as fast as they could grasp them. They caught up one child after the other, and, without heeding the resistance which some offered, adjusted the belts, and, as fast as this was done, they assisted in pushing the children toward the companionway. [Illustration: _A Contact Mine_]