The next morning came clear, and the sight of the mighty slope of Mauna Loa, lit up by the rising sun, was a grand spectacle. It looked gentle and easy of ascent, wooded here and there, and here and there showing broad, black streaks from the lava overflows at the summit in recent years; but remembering that it was nearly four thousand feet higher than Haleakala, I had no desire to climb it. This mountain and its companion, Mauna Kea, are the highest island mountains in the world. The stage rolled us back through the fern forest to the railway station and thence on to Hilo again, where in good time, in the afternoon, we went aboard the steamer; and the next morning we were again in the harbor of Honolulu, glad we had made the inter-island trip, and above all glad that we had seen Haleakala. VI THE OLD ICE-FLOOD I He was a bold man who first conceived the idea of the great continental ice-sheet which in Pleistocene times covered most of the northern part of the continent, and played such a part in shaping the land as we know it. That bold man was Agassiz, who, however, was not bold enough to accept the theory of evolution as propounded by Darwin. The idea of the great glacier did not conflict with Agassiz's religious predilections, and the theory of evolution did. It was a bold generalization, this of the continental ice-sheet, one of the master-strokes of the scientific imagination. It was about the year 1840 that Agassiz, fresh from the glaciers of the Alps, went to Scotland looking for the tracks of the old glaciers, and he found them at once when he landed near Glasgow. We can all find them now on almost every walk we take to the fields and hills; but until our eyes are opened, how blind we are to them! We are like people who camp on the trail of an army and never suspect an army has passed, though the ruts made by their wagons and artillery and the ruins of their intrenchments are everywhere visible.