The inventor grasped the telephone, which communicated with the engine-room. “Stop your engines,” he called, “and sink her.” “Right you are,” came the answer. Gliding gently forward by her own momentum, as the propellers ceased to revolve, the _Seal_ nosed almost up to the edge of the barrier; then she sank slowly, her crew keeping a sharp look-out for an opening in the grim wall. Fifty--sixty--eighty fathoms she sank, and still the ice glittered before her. A hundred--and still no opening, and Mervyn’s face grew strained and white as the moments sped by. What if the base of the great ice barrier rested upon the ocean bed? What if it were not a floating chain of ice mountains, as he believed, but an immovable line of cliffs, their icy feet gripping the sandy bed of the Polar Sea? Such might easily be the case; and if so, what then? Ay! what then? The scientist answered the question for himself. A humiliating retreat from the barrier which had battled them; a still more humiliating return to their native shore, there to endure the scoffs and sneers of every dabbler in science who could put pen to paper. He had staked so much on the outcome of this expedition. His very reputation trembled in the balance. Never again would he be able to lift his head among his rivals, should this, his pet theory, prove a delusion. Still lower the submarine sank, and no sign was there of an ending of the ice; lower, every plate in her hull creaking beneath the enormous pressure. Mervyn glanced uneasily at Garth. “Will she stand it?” he asked, in a hoarse whisper. The inventor consulted a small dial set in the turret wall. “Yes,” he replied; “she was built to stand greater pressure than this.” “Thank heaven!” muttered the scientist. “You know what this means to me, Garth? Failure spells ruin!” “We’re not going to fail,” Garth retorted, cheerfully; “we’ll pull through if I have to blow the barrier into fragments first.” His hopeful words somewhat revived the drooping spirits of the professor, and he turned once more to the window with renewed hope. But still no break appeared in the grim face of the ice-cliffs. Caves there were in plenty, small openings worn in the ice by the action of the water, but not one was large enough for the _Seal_ even to insert her nose; yet each of these Mervyn eyed anxiously as the vessel sank past them, hoping to discover in one of them a passage through the heart of the barrier. Then, amidst the creaking and groaning of the vessel, came a slight shock, and she ceased to sink. “I guess we’ve struck bottom,” the Yankee said, glancing keenly at Mervyn. He grasped the tube. “Ease her up half a dozen yards,” he called, “and start your engines at four knots.” Almost ere he had ceased to speak, the _Seal_ rose for a few feet, until her keel no longer rested on the sand; her screw: commenced to revolve, and, under the millionaire’s able guidance, she crept slowly along the base of the ice-cliffs.