"What! push it down by power?" asked Alfred.
"Exactly; these vessels have fins, the same as fish, so arranged that if they are properly turned and the ship moves forward, it will dive, and continue to go down at an angle as long as the fins are properly set. If the vessel should stop moving the submarine would come to the top, because it is lighter than the water," responded the captain.
With a click the door of their prison cabin opened and a seaman informed them that their breakfast was ready. They passed through the narrow door, and edged their way along a tortuous path that led to the rear, where they entered what might be called a miniature galley, on one side of which was a narrow shelf containing food of various descriptions.
There was room only for the attendant to pass while they were seated. An abundance of the best food was served, cereals, and even fruit, forming part of the menu. Each of these vessels carry from twenty-two to thirty men, but there were in sight in the dining room only ten, besides the cook and waiter.
After the meal, the captain inquired of the officer at the main hatch whether they would be permitted to go on deck.
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.
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.