They were passed aboard by the sentry and there on the deck welcomed by the officers and members of the _Dewey's_ crew. Turned over to big Bill Witt, one of the crew, they were directed to go below and be assigned to their quarters. Down through the hatchway clambered Witt, followed close by Ted and Jack, and in another moment they found themselves in the engine room. Electric lights glowed behind wired enclosures. Well aft were the motors and oil engines, around them switchboards and other electrical apparatus---a maze of intricate machinery that filled all the stern space. The air was hazy and smelled strong of oils and gases. Huge electric fans swept the foul air along the passageway and up through the hatchways, while other fans placed near the ventilators distributed the fresh air as it poured into the vessel, drawn by the suction. 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.