Clambering cautiously along the horizontal strut that strengthened the curved girder, the men made a careful survey of the metal cylinder before attempting to handle it. Apparently it had been in the water for some weeks, for barnacles and slimy weeds were adhering to its surface. The "horns" or "feelers" were, fortunately, pointing away from the hull of the submarine; nevertheless the task of disengaging the mine without allowing it to scrape or jam against any form of solid resistance was fraught with danger. A slight tap upon one of those numerous spike-like projections would result in death to every man on board. Examination proved that not only was the mine with its attendant anchor-chamber entangled by means of a hempen rope, but a length of wire had stubbornly intertwined itself round a portion of the girder, so that the mine, swinging towards the metal hull, was practically midway between it and the curved side of the vessel. "A hack-saw there," ordered the Lieutenant-Commander. "Oil it well, or the rasping will give the show away." The required tool was quickly forthcoming, and the two men tackled their dangerous task. For twenty minutes they worked desperately, momentarily expecting to be "picked up" by the search-lights that were playing ominously close to the dark-grey hull of the submarine. "Through, sir," announced one of the men breathlessly. "Shall we topple it over?" "No, no," replied the skipper hurriedly. "Are you quite sure that everything's clear?" "Aye, aye, sir." The mine was now held in position only by the triangle formed by the girder, its horizontal brace, and a two-inch teak plank placed diagonally across the metal work. Fortunately the sea was now calm and the submarine's motion barely perceptible. "Diving-stations," ordered Huxtable. "It's neck or nothing." The water-tight hatches were closed and secured, and water admitted into the ballast tanks, both main and auxiliary, for it was her commander's intention to submerge the submarine in a vertical position without having recourse to the use of the propeller and diving-planes. In sinking, the submarine, he hoped, would be automatically freed of its dangerous encumbrance, since the buoyancy of the mine would float it clear when the craft was completely submerged. Instinctively Dick shut his jaw tightly as he heard the hiss of the water pouring into the tanks. He fully realized the delicate operation, for a list of any magnitude would result in the mine toppling over from its insecure perch as it did so. It was not pleasant to realize that he was in a hermetically sealed steel box with a dangerous neighbour in the shape of seventy-six pounds of gun-cotton. He glanced at the Lieutenant-Commander, who was peering anxiously through the slit in the conning-tower, and although he moved not a muscle the perspiration was standing out in beads on his temples. Presently he turned his head.