At seven the next morning the _Forward_ was held under steam, ready to profit by the smallest issue. Johnson was charged with setting fire to the wick, which, according to calculation, would burn for half an hour before setting fire to the mine. Johnson had, therefore, plenty of time to regain the brig; ten minutes after having executed Hatteras's order he was again at his post. The crew remained on deck, for the weather was dry and bright; it had left off snowing. Hatteras was on the poop, chronometer in hand, counting the minutes; Shandon and the doctor were with him. At eight thirty-five a dull explosion was heard, much less loud than any one would have supposed. The outline of the mountains was changed all at once as if by an earthquake; thick white smoke rose up to a considerable height in the sky, leaving long crevices in the iceberg, the top part of which fell in pieces all round the _Forward_. But the path was not yet free; large blocks of ice remained suspended above the pass on the adjacent mountains, and there was every reason to fear that they would fall and close up the passage. Hatteras took in the situation at one glance. "Wolsten!" cried he. The gunsmith hastened up. "Yes, captain?" cried he. "Load the gun in the bow with a triple charge," said Hatteras, "and wad it as hard as possible." "Are we going to attack the mountain with cannon-balls?" asked the doctor. "No," answered Hatteras, "that would be useless. No bullet, Wolsten, but a triple charge of powder. Look sharp!" A few minutes after the gun was loaded. "What does he mean to do without a bullet?" muttered Shandon between his teeth. "We shall soon see," answered the doctor. "Ready, captain!" called out Wolsten. "All right!" replied Hatteras. "Brunton!" he called out to the engineer, "a few turns ahead." Brunton opened the sliders, and the screw being put in movement, the _Forward_ neared the mined mountain. "Aim at the pass!" cried the captain to the gunsmith. The latter obeyed, and when the brig was only half a cable's length from it, Hatteras called out: "Fire!" A formidable report followed his order, and the blocks, shaken by the atmospheric commotion, were suddenly precipitated into the sea; the disturbance amongst the strata of the air had been sufficient to accomplish this. "All steam on, Brunton! Straight for the pass, Johnson!" The latter was at the helm; the brig, driven along by her screw, which turned in the foaming waves, dashed into the middle of the then opened pass; it was time, for scarcely had the _Forward_ cleared the opening than her prison closed up again behind her. It was a thrilling moment, and on board there was only one stout and undisturbed heart--that of the captain. The crew, astonished at the manoeuvre, cried out: "Hurrah for the captain!" CHAPTER XIV EXPEDITION IN SEARCH OF FRANKLIN