Page:South - the story of Shackleton's last expedition, 1914-1917.djvu/113

 of the object, a small pressure-ridge being given the appearance of a line of battlements or towering cliffs. The mirage is produced by refraction and is intensified by the columns of comparatively warm air rising from several cracks and leads that have opened eight to twenty miles away north and south."

We noticed this day that a considerable change had taken place in our position relative to the Rampart Berg. It appeared that a big lead had opened and that there had been some differential movement of the pack. The opening movement might presage renewed pressure. A few hours later the dog teams, returning from exercise, crossed a narrow crack that had appeared ahead of the ship. This crack opened quickly to 60 ft. and would have given us trouble if the dogs had been left on the wrong side. It closed on the 25th and pressure followed in its neighbourhood.

On August 24 we were two miles north of the latitude of Morell's farthest south, and over 10° of longitude, or more than 200 miles, west of his position. From the mast-head no land could be seen within twenty miles, and no land of over 500 ft. altitude could have escaped observation on our side of long. 52° W. A sounding of 1900 fathoms on August 25 was further evidence of the non-existence of New South Greenland. There was some movement of the ice near the ship during the concluding days of the month. All hands were called out in the night of August 26, sounds of pressure having been followed by the cracking of the ice alongside the ship, but the trouble did not develop immediately. Late on the night of the 31st the ice began to work ahead of the ship and along the port side. Creaking and groaning of timbers, accompanied by loud snapping sounds fore and aft, told their story of strain. The pressure continued during the following day, beams and deck planks occasionally buckling to the strain. The ponderous floes were grinding against each other under the influence of wind and current, and our ship seemed to occupy for the time being an undesirable position near the centre of the disturbance; but she resisted staunchly and showed no sign of water in the bilges, although she had not been pumped out for six months. The pack extended to the horizon