From the engine room the boys walked forward into the control chamber—–­the base of the conning tower—–­the very heart and brain of the undersea ship.  Here were the many levers controlling the ballast tanks, Witt explaining to the boys that the submarine was submerged and raised again by filling the tanks with water and expelling it again to rise by blowing it out with compressed air.  Here also was the depth dial and the indicator bands that showed when the ship was going down or ascending again, the figures being marked off in feet on the dial just like a clock.  Here also was the gyro-compass by which the ship was steered when submerged; here also the torpedo control by means of which the torpedoes were discharged in firing.  And, yes, here was the periscope—–­the great eye of the submarine—–­a long tube running up through the conning tower twenty feet above the commander’s turret of steel.

“Something like the folding telescope we have at home to look at pictures,” mumbled Jack aside to Ted.

To the boys’ great delight they were allowed to put their eyes to the hood and gaze into the periscope.  In turn they “took a peep.”  What they saw was the forward deck of the Dewey, the guns in position, other vessels moored nearby and the blue expanse of water stretching out into the harbor and on to the open sea.  It was rather an exciting moment for the two “landlubbers.”

Witt next showed them forward through the officers’ quarters and the wireless room into the torpedo compartment.  This interested them greatly.  On either side of the vessel, chained to the sides of the hull on long runners that led up to the firing tubes, were the massive torpedoes, ready to be pushed forward for insertion in the firing chambers.  Chief Gunner Mowrey was working over one of the breech caps and turned to meet the new recruits.

“Glad to meet you, mates,” was his hearty salutation.

The boys listened attentively while Mowrey was telling Witt of some great “hits” they had made in practice earlier in the morning.  Bill Witt showed the boys in turn the bunks that folded out of the sides of the vessel in which the crew slept, the electric stove for cooking food in the ship’s tiny galley, the ballast tanks and the storage batteries running along the keel of the vessel underneath the steel flooring.

Climbing up on deck again through the conning tower, the boys found themselves out on top of the projection in what Witt explained was the deck steering station whence the Dewey was navigated when cruising on the surface.  Down on the deck the boys inspected the smart-looking four-inch guns with which they later were to become better acquainted, and the trim little anti-aircraft guns to be used in case of attack by Zeppelins or aeroplanes.

“Keep your eyes and ears wide open all the time; remember what you are told and you’ll soon catch on,” Witt told them.