We were now at the farthest point at which it was possible to use the dogs, at our actual climbing base, and the time had come for Johnny and the dogs to go down to the base camp for good. We should have liked to keep the boy, so good-natured and amiable he was and so keen for further climbing; but the dogs must be tended, and the main food for them was yet to seek on the foot-hills with the rifle. So on 9th May down they went, Tatum and the writer escorting them with the rope past the crevasses as far as the first glacier camp, and then toiling slowly up the glacier again, thankful that it was for the last time. That was one of the sultriest and most sweltering days either of us ever remembered, a moist heat of sun beating down through vapor, with never a breath of breeze--a stifling, stewing day that, with the steep climb added, completely exhausted and prostrated us. [Sidenote: The Great Ice-Fall] It is important that the reader should be able to see, in his mind's eye, the situation of our camp at the head of the glacier, because to do so is to grasp the simple orography of this face of the mountain, and to understand the route of its ascent, probably the only route by which it can be ascended. Standing beside the tent, facing in the direction we have journeyed, the great highway of the glacier comes to an abrupt end, a cul-de-sac. On the right hand the wall of the glacier towers up, with enormous precipitous cliffs incrusted with hanging ice, to the North Peak of the mountain, eight or nine thousand feet above us. About at right angles to the end of the glacier, and four thousand feet above it, is another glacier, which discharges by an almost perpendicular ice-fall upon the floor of the glacier below.[2] The left-hand wall of the glacier, described some pages back as a stupendous escarpment of ice-covered rock, breaks rapidly down into a comparatively low ridge, which sweeps to the right, encloses the head of the glacier, and then rises rapidly to the glacier above, and still rises to form the left-hand wall of that glacier, and finally the southern or higher peak of the mountain. So the upper glacier separates the two great peaks of the mountain and discharges at right angles into the lower glacier. And the walls of the lower glacier sweep around and rise to form the walls of the upper glacier, and ultimately the summits of the mountain. To reach the peaks one must first reach the upper glacier, and the southern or left-hand wall of the lower glacier, where it breaks down into the ridge that encloses the head of the glacier, is the only possible means by which the upper basin may be reached. This ridge, then, called by Parker and Browne the Northeast Ridge (and we have kept that designation, though with some doubt as to its correctness), presented itself as the next stage in our climb. [Sidenote: Last Year's Earthquake]