But, to return—­although the men worked as only those can who toil for liberation from long imprisonment, no impression worth mentioning could be made on the ice.  At length the attempt to rend it by means of gunpowder was made.

A jar containing about thirty pounds of powder was sunk in a hole in an immense block of ice which lay close against the stern of the ship.  Mivins, being light of foot, was set to fire the train.  He did so, and ran—­ran so fast that he missed his footing in leaping over a chasm, and had well-nigh fallen into the water below.  There was a whiz and a loud report, and the enormous mass of ice heaved upwards in the centre, and fell back in huge fragments.  So far the result was satisfactory, and the men were immediately set to sink several charges in various directions around the vessel, to be in readiness for the highest tide, which was soon expected.  Warps and hawsers were also got out and fixed to the seaward masses, ready to heave on them at a moment’s notice; the ship was lightened as much as possible by lifting her stores upon the ice; and the whole crew—­captain, mates, and all—­worked and heaved like horses, until the perspiration streamed from their faces, while Mizzle kept supplying them with a constant deluge of hot coffee.  Fred and the young surgeon, too, worked like the rest, with their coats off, handkerchiefs bound round their heads, and shirt-sleeves tucked up to their shoulders.

At last the tide rose—­inch by inch, and slowly, as if it grudged to give them even a chance of escape.

Mivins grew impatient and unbelieving under it.  “I don’t think it’ll rise another hinch,” he remarked to O’Riley, who stood near him.

“Niver fear, boy.  The capting knows a sight better than you do, and he says it’ll rise a fut yit.”

“Does he?” asked Grim, who was also beginning to despond.

“Ov coorse he does.  Sure he towld me in a confidintial way, just before he wint to turn in last night—­if it wasn’t yisturday forenoon, for it’s meself as niver knows an hour o’ the day since the sun became dissipated, and tuck to sitting up all night in this fashion.”

“Shut up yer tatie-trap and open yer weather-eye,” muttered Buzzby, who had charge of the gang; “there’ll be time enough to speak after we’re off.”

Gradually, as the tide rose, the ice and the ship moved, and it became evident that the latter was almost afloat, though the former seemed to be only partly raised from the ground.  The men were at their several posts ready for instant action, and gazing in anxious expectation at the captain, who stood, watch in hand, ready to give the word.

“Now, then, fire!” he said in a low voice.

In a moment the ice round the ship was rent, and upheaved, as if some leviathan of the deep were rising from beneath it, and the vessel swung slowly round.  A loud cheer burst from the men.

“Now, lads, heave with a will!” roared the captain.