By this time it was realised that winter quarters must be selected, and the _Discovery_ sailed to that part of the sea where Mount Erebus and Mount Terror reared their lofty heads on the land. Examining the land for a suitable site for the camp, it was learned that both Erebus and Terror are situated on an island, and not, as was formerly believed, on the mainland. At the opposite end of the island another smaller volcanic mount was seen, with a still smaller one between it and the two giants. The larger of these was named Mount Discovery, and, near its base, the site of the camp was chosen. The ship was worked in as close to the shore as was possible before the heavy frost set in, and, as she was well constructed to withstand the pressure of ice, she remained in this position until, after the second winter had been passed, the relief ship arrived with sufficient explosives to blast a way out of the ice. As soon as the members of the expedition had settled down and all was made snug, trips were taken in all directions along the coast and over the ice. The longest trip, taken in the following September, was arranged for, food depôts being established as far to the south as the stores could be conveyed. On this trip, the historic one of the expedition, only three went. These were Captain Scott, Lieutenant Shackleton, and Dr. Wilson. They had dogs with them at the start, but the animals grew sick and weak, and were, at last, quite useless in dragging the sledges. The three harnessed themselves to the sledges in place of the dogs, and, handicapped with this weight of 240 lbs. each, they pushed on until they reached 82° 17' S. From the position they then occupied they were able to see as far as 83° 20' S., and would have gone as far, if not farther, but for an insuperable obstacle that confronted them. The route they followed was over rough ice, often yawning with deep crevasses, down which the sledges had to be lowered and then hauled up on the other side. Some of them were veritable chasms, but they faded into insignificance when compared with the one which opened before the explorers at the end of the march. For a time they examined this mighty ice ravine to see if it were not possible, one way or another, to get across. The descent might have been possible, and there was no great difficulty in crossing the floor of it, but the far side rose in an unbroken precipice, and they recognised it as insurmountable, even to such daring and intrepid climbers as themselves.