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.
"At that!" he ordered, addressing the men standing by the valve of the ballast chamber. "Turn horizontal rudders to ten degrees down. Half speed ahead."
A gasp of relief echoed through the confined space. The men gave a cheer. They understood: one danger had been successfully combated.
The steady thud of the throttled-down motors alone imparted the sense of motion as the submarine, fifty feet beneath the surface, resumed her blind grope up The Narrows.
Twice only during the negotiation of that intricate passage did the Lieutenant-Commander show the top of the periscope above water. The first observation revealed the feet that Nagara was well on the starboard hand, and that an alteration of helm was necessary to avoid piling the submerged craft upon shoals that, owing to the irregularity of coast-line, were directly ahead.