After the meal, the captain inquired of the officer at the main hatch whether they would be permitted to go on deck. "I have no orders," he replied. Meanwhile, the boys had an opportunity to investigate the mysteries of the interior, for it was well lighted. "What are those long drums ahead there?" asked Alfred. "I think they are the casings which carry the torpedoes," replied the captain. "If you look beyond you will see the rear ends of the tubes which receive the torpedoes. The cylinders in sight hold the torpedoes until they are ready to be placed in the tubes and shot out of them." "You have orders to go on deck," the under officer at the bottom of the hatch now informed them. This was an invitation to which they quickly responded. They ascended, and found the sun hidden, and the sea about them calm. Glancing across the broad expanse of water, not a sail was in sight. It was a cold, gray morning, ordinarily uninviting weather, but after the house of confinement it was enjoyed to the fullest extent. "Down below!" shouted a voice. The boys looked around in surprise, for they had been on deck less than ten minutes. "Clear the deck!" shouted the same voice. The boys, with the captain, were hustled forward into the conning tower, and the iron door closed with a bang. The boys were permitted to stop only long enough to see two men turn eight swinging bolts, which hung about the margins of the doors, and quickly screw them up against the jamb. The lieutenant was leaning over a narrow table on which was a chart, and gazing through a crystal-covered port in the front of the conning tower. A bell tinkled, machinery began to turn and impart its vibration to the ship, and it was again a living thing. It glided forward with the same rhythmic noises for a half-hour, and then two bells were heard. The character of the sounds from the machinery changed; they seemed to move forward with less effort, and as they felt the same inclination in the motion of the ship, all were now satisfied that she was again submerging. Fortunately, they were not confined to their room, and, although no verbal orders had been given for the various operations required to handle the vessel, the prisoners had an opportunity to judge of what was going on. Thus, when the signal was given to change the motive power from the internal combustion engines to electricity, they could see the engine stop, and an attendant shift the clutch which engaged the electric motors. A dial swinging over a card alongside a pair of levers indicated the direction of movement, while another gave not only the inclination of the ship, but its speed as well. These things were very fascinating to the boys, but their attention was now attracted to a still more interesting scene. A bell forward gave two short, quick snaps. Four men sprang forward and stood at attention, two on each side of the tube at the right of the hold.