“We were now feeling the strain of the unaccustomed marching. We had done little walking since January and our muscles were out of tune. Skirting the base of the mountain above us, we came to a gigantic bergschrund, a mile and a half long and 1000 ft. deep. We passed through it, under the towering precipice of ice, and at the far end we had another meal and a short rest. This was at 12:30 p.m. Half a pot of steaming Bovril ration warmed us up, and when we marched again ice-inclines at angles of 45 degrees.

“Once more we started for the crest. After another weary climb we reached the top. The snow lay thinly on blue ice at the ridge, and we had to cut steps over the last fifty yards. The same precipice lay below, and my eyes searched vainly for a way down.

“The hot sun had loosened the snow, which was now in a treacherous condition, and we had to pick our way carefully.

“Looking back, we could see that a fog was rolling up behind us and meeting in the valleys a fog that was coming up from the east. The creeping grey clouds were a plain warning that we must get down to lower levels before becoming enveloped.”

— Ernest Shackleton, South