"I don't fancy so, sir," was the reply. "They will trust to their mines. Since the last war these johnnies think twice before tackling an ironclad." "Very well, then--carry on. Are your men ready, Mr. Palmer?" "Ay, ay, sir!" "Then look sharp about it, if we are to warp into the dock before sunset. By the bye, Mr. Tregarthen," he continued, wheeling round and facing Gerald, "have you had any experience of creeping?" "Plenty of it in the Vernon, sir." "I've changed my mind; you may go with Mr. Palmer." Accompanied by Stockton, who, now that his chum was permitted to take part in the expedition, wanted to share in the perils, Gerald followed the lieutenant and a dozen men down to the orlop-deck. Here, almost amidships, was an oval-shaped steel box, projecting about three feet above the deck. Unfastening a massive securing-bar, one of the men touched a knob, and the huge rubber-lined lid slowly turned on its hinges and disclosed a similar, though slightly smaller, box. It was the conning-tower of the submarine. To Stockton the next few minutes seemed like a dream. The lid of the conning-tower was raised, and five of the sailors descended into the recesses of the little craft. Palmer then motioned to Gerald to precede him, and with a hasty grasp of the hand Jack bade his friend a silent farewell. Then Palmer followed, and ere the lid closed with a ponderous clang Stockton saw the dim glimmer of the electric light shining upon a mass of complicated machinery. "Stand aside, please, sir!" said one of the men who still remained on the orlop-deck. The cover of the outer box descended, the securing bar was carefully locked, and the sound of inrushing water was borne faintly to Stockton's anxious ears. "They're off now, sir," added the seaman. "If you go on deck you'll be able to see something of what they're up to." From the top of the conning-tower, which in lieu of the demolished bridge and charthouse was now the highest practicable coign of vantage, Stockton and several of the officers watched the tip of the submarine's periscope glide slowly along the surface of the water, while some 30ft. in the rear was the tell-tale swirl of the vessel's propeller and the characteristic wake of the submersed craft. Every available glass was brought to bear upon the receding pole-like object, as it kept an unswerving course straight for the entrance of the harbour. Suddenly a column of water was thrown 50ft. in the air. Stockton gave an involuntary gasp of horror--what if the submarine had fouled one of the deadly mines? A minute passed. Even Captain Brookes began to look anxious, for no trace of the periscope was now discernible. "There she goes again!" shouted one of the men, as another slender column rose high in the air.