“I’ve made a find!” he exclaimed.  “These tusks we may take with us, and old ivory is about as valuable as precious stones.”

The discovery seemed to waken the Doctor to their peril.

“That walrus,” he said, “wandered in here and was drowned by the rising tide.  He can breathe under water, but cannot stay down over ten minutes.  We can’t breathe at all under water.  The tide is setting in.”

These words sent the crew scurrying back to the submarine.  Already the tide had risen sufficiently to float the craft.  All hands hastened to re-embark.

“If we set our course directly at right-angles to this beach and keep it there,” said Dave, “it should bring us to safety.”

This was done, and, after many a turn and twist, they caught a gleam of light.  Submerging, they were soon beneath the ice-floe once more.  With a sigh of relief, Dave gave the order to rise at the first water-hole.  There they might take their bearings.

A half-hour later the party was gathered on the deck gazing away at an island above which there towered a snow-capped mountain.  Down the side of the mountain might be distinguished the winding, blue course of a great glacier.

“Our glacier!” said Dave.  “Some glacier, I’ll say!”

“Our glacier!” repeated a jackie.  “Long may she glide!”

The course was set at an angle to the island.  This would carry them past any treacherous sand-bars.  They would then take another tack and resume their former course.

At a few minutes before noon that day they rose far from the island.  The sun, a pale yellow disk, shone through a thin haze close to the surface of the pack.  And yet it was high noon.  This was, perhaps, to be their last bearing taken by the light of the sun.  Henceforth, the moon and the stars must guide them.  Whereas all former polar expeditions were carried forward only during the summer months, when the sun shone night and day, they, as well as their rivals, must drive on straight into the deep mysteries of the dreaded Arctic night.

CHAPTER XVI

WRECKED

“All aboard!  Change here for all way stations; our next stop is the Pole!”

Barney, the daring aviator, sang the words cheerfully, as he settled himself in his place at the wheel.  He hardly felt the cheerfulness his tone implied.  True, they had spent twelve days repairing the damage done to the plane by the wind and its collision with the white bear, but it was a rather patched-up affair now it was finished—­as it needs must be with the few materials and tools at their command.  As he had expressed it to Bruce only the night before:  they had a crippled wing, and a bird with a broken pinion never soars so high again, even if it is a bird of fabric, wood and steel.

However, he was truly glad to be getting away on what they hoped might be their last lap.  The grave-like silence of the Arctic, with its glistening whiteness everywhere, had gripped his nerves.