It was evident, then, that they must slip up on their prey without being seen.  This would be a comparatively simple matter, since the tumbled ridges of ice afforded ideal hiding-places.  When close enough, Barney, who was the stronger of the two, was to drive the harpoon-point through the thick skin of the creature.  This harpoon-point was fastened to a rawhide rope.  He must instantly drive a copper-pointed lance into the ice, and wrapping the skin-rope about it, close to the ice-surface, hold on like grim death until Bruce dispatched the creature with his rifle.  Wherever the beast was, in a small water-hole kept opened by himself, or a larger one formed by the shifting floes, their success would depend on Barney’s ability to keep the rope free from jagged edges which might cut it, and Bruce’s skill at quickly getting in a fatal shot.  At regular intervals the walrus must rise for air, and this would give the opportunity for Bruce to get in his work.

“He’s a moose!” whispered Bruce, as they crept close to the rather broad waters-hole and eyed the creature through a crack between upended ice-cakes.

“Tusks two feet and a half long!  Must weigh a ton and a half!” Already Barney felt his muscles ache from the strain.

“Well, here’s for it!” He exclaimed, coiling his skin-rope.  The next instant there came a loud thwack, which told that the boy’s shaft had found its mark.  Instantly there was a hoarse bellow and then a wild splashing in the water.  Bruce was at the top of a pressure ridge, ready for action.  Barney had made his shaft secure, but then there came a strain that made the veins stand out on his forehead.  Suddenly the strain slackened.

“Be ready!  He’s coming—­” Barney did not finish, for from the churning water the walrus thrust his massive head, snorting and foaming.  The rifle cracked.

Silently the great creature sank, but this time the foaming water showed a fleck of red where the walrus disappeared.

“Got him!” cried Bruce triumphantly.

But this time the strain on the lance was redoubled.

“Try—­try to hit a vital—­vital spot,” panted Barney, as the strain lessened once more.  “Behind front flipper—­in the eye.”

Again the water foamed.  Again the rifle cracked.  More blood!  Another plunge, and again the strain seemed redoubled.

“I—­can’t—­hold much—­longer,” Barney gasped.

Springing down from the pinnacle, Bruce ran to the edge of the pool, and, leaping upon a floating ice-cake, waited again.

This time his aim was better.

The strain when the walrus sank was not so great.

“Doing fine,” breathed Barney.  “Next time we’ll—­”

Again he did not finish, for, unexpectedly, his friend shot up in the air, to fall sprawling upon the cake of ice and cling there while it tilted to an angle of forty-five degrees.  The walrus had risen beneath the cake and split it in two.  Bruce was stunned by his fall, but Barney’s warning cry roused him.  One glance revealed his perilous position.  The piece of ice to which he clung had been thrust toward the center of the pool.  Even now the gap was too wide for him to leap.  To plunge into the water, with the thermometer forty below, was to court death.