He had scarcely closed the door after he had withdrawn, when Lunsley sprang to the wheel again, and made a vigorous effort to throw it over as he had directed the wheelman to do. Jack braced his feet against the spokes underneath, and for a moment prevented the scoundrel from accomplishing his purpose. But the pilot was a powerful man, and Jack found himself defeated in his attempt by main strength to prevent the Middy from being thrown ashore. He did not give up the ship: and this was precisely what it would have amounted to, if she had got aground there; for the rebels could have knocked her to pieces in five minutes if she would only “hold still” long enough. When he found he was not a match in physical strength for the burly pilot, he had the presence of mind to strike two bells, followed by three; which were the signals respectively to stop and back her. The traitor, finding the steamer was receding from the shoal sprang forward towards the bell-pulls. There was a heavy hard-wood stick in the wheel-house, which had been used to pry up the iron screens into position. Jack grasped this weapon; and, as the pilot placed his hand upon the pull, he struck him a heavy blow upon the back of the head, which felled him to the deck. Jack then rang two bells,--stop her; one bell,--ahead slow; four bells,--ahead, full speed. CHAPTER XXII. JACK ASHORE. The roar of the guns, and the busy scenes in every part of the steamer, had prevented anyone from noticing the affair which had just transpired in the wheel-house. The Middy was completely enveloped in the smoke of her own guns; and, though Captain Bankhead was on the hurricane-deck, he had no knowledge of the important event which had saved his vessel from destruction. The stopping, backing, and going ahead again, had been noticed, of course; but they were supposed to have been occasioned by some difficulty in the navigation. The battery which had opened upon the Middy was situated upon a point of land at a bend in the river, and on the port-hand. Near the land, there was a broad shoal; for the current, in turning this curve, would, by its natural law, sweep round to the opposite shore. As soon, therefore, as Jack found himself his own master in the wheel-house, he put the helm well a-port, and kept the steamer away from the dangerous ground. Captain Bankhead, who was directing the action on deck, had passed the word for Tom Longstone as soon as he was conscious of any treachery on the part of Lunsley. Before Tom came up from below, he again opened the door of the wheel-house, where he discovered the prostrate form of the traitor. “What’s this, Somers?” demanded Captain Bankhead. “He is a traitor, sir! He tried to take the wheel out of my hands, and throw the steamer on that shoal!” replied Jack in high excitement. “I knocked him down with this club, and kept her off.”