Pen broke out with a fearful oath.
"Silence!" cried a voice which it was impossible to recognize in the roar of the hurricane.
The mass appeared to be falling upon the brig, and there was an indefinable moment of terror; the men, dropping their poles, ran aft in spite of Shandon's orders.
Suddenly, a terrible noise was heard; a real water-spout fell on the deck of the brig, which was lifted in the air by a huge wave. The crew uttered a cry of terror, while Garry, still firm at the wheel, kept the course of the Forward steady, in spite of the fearful lurch.
And when they looked for the mountain of ice, it had disappeared; the passage was free, and beyond, a long channel, lit up by the sun, allowed the brig to continue her advance.
"Well, Dr. Clawbonny," said Johnson, "can you explain that?"
"It's very simple, my friend," answered the doctor. "It happens very often; when these floating masses get detached in a thaw, they float away in perfect equilibrium; but as they get towards the south, where the water is relatively warmer, their base, eaten away by running into other pieces, begins to melt, and be undermined; then comes a moment when the centre of gravity is displaced, and they turn upside down. Only, if this had happened two minutes later, it would have fallen on the brig and crushed us beneath it."