"Simply that we are inside an iceberg," replied Captain Stormleigh calmly, for now that way was off the ship his anxiety had considerably lessened. "There's a wall of ice on three sides of us at least, since we've sighted it. There's ice under us, otherwise the lead would give a jolly sight more than six fathoms, and there is, or was, ice above us, otherwise we shouldn't have lost part of our foremast."
"What's to be done?" asked Ranworth anxiously.
"Grope our way out—if we can," replied the skipper. "Unless I'm very much mistaken——"
His words were interrupted by a low rumble that quickly increased into a roar like thunder. Almost at the same time the hitherto calm sea was strangely agitated. A dull shock was distinctly felt under the ship's keel.
"Berg breaking up," remarked Captain Stormleigh, as calmly as possible, yet fear was gripping his mind. He alone knew the danger. The Polarity was almost in contact with a mountain of ice, which was on the point of toppling over. Every minute was precious, and a way had yet to be found to extricate the ship from her hazardous position.
Suddenly—owing to the disturbance of the atmosphere caused by the fall of a huge portion of the berg—the fog was riven asunder, and an awe-inspiring sight met the eyes of the two lads.
The Polarity lay in a deep narrow inlet. On three sides rose a continuous wall of ice, terminating three hundred feet above the surface in pinnacles of fantastic shape. From this precipice masses of ice jutted out at varying angles. It was against one of these unstable projections that the foremast of the ship had struck.
The opening by which the Polarity had, by a pure fluke, entered the ice-incircled inlet was now visible; a gap roughly a hundred yards in width at the surface, and two-thirds of that distance from the nearmost of the opposite peaks. It was this part of the berg that threatened to collapse next. The overlapping mass was groaning ominously. Should a slide occur, the Polarity would be hopelessly trapped.
Not only was the ship almost surrounded by the berg, but underneath her keel was a ledge of ice that was part and parcel of the floating mountain of frozen water.
Again a terrific crash announced that another fall of the ice had taken place. Evidently the slide was of great size, sufficient to imperil the stability of the whole berg. The waters of the inlet were violently agitated as the towering mass swayed.