The pack within our range of vision was being subjected to enormous compression, such as might be caused by cyclonic winds, opposing ocean currents, or constriction in a channel of some description.

The pressure-ridges, massive and threatening, testified to the overwhelming nature of the forces that were at work.

Huge blocks of ice, weighing many tons, were lifted into the air and tossed aside as other masses rose beneath them.

We were helpless intruders in a strange world, our lives dependent upon the play of grim elementary forces that made a mock of our puny efforts.

I scarcely dared hope now that the 'Endurance' would live, and throughout that anxious day I reviewed again the plans made long before for the sledging journey that we must make in the event of our having to take to the ice.