The importance of having a reserve of power on mountain expeditions cannot be too strongly insisted upon. We always had some in hand, and were never pressed, or overworked, so long as we were together. Come what might, we were ready for it. But by a series of chances, which I shall never cease to regret, I was first obliged to part with Croz, and then to dismiss the others;(156) and so, deviating from the course that I had deliberately adopted, which was successful in practice because it was sound in principle, became fortuitously a member of an expedition that ended with the catastrophe which brings this book, and brought my scrambles amongst the Alps, to a close.(157) On June 15 we went, from Turtman to Z’meiden, and thence over the Forcletta pass to Zinal. We diverged from the summit of the pass up some neighbouring heights to inspect the Grand Cornier, and I decided to have nothing to do with its northern side. It seemed quite safe to pronounce it inaccessible from that direction, although it was more than seven miles away. On the 16th we left Zinal at 2.5 A.M., having been for a moment greatly surprised by an entry in the hotel-book,(158) and ascending by the Zinal glacier, and giving the base of our mountain a wide berth in order that it might be better examined, passed gradually right round to its south, before a way up it was seen.(159) At 8.30 we arrived upon the plateau of the glacier that descends towards the east, between the Grand Cornier and the Dent Blanche, and from this place a route was readily traced. We steered to the north (as shown upon the map) over the glacier, towards the ridge that descends to the east; gained it by mounting snow-slopes, and followed it to the summit, which was arrived at before half-past twelve. From first to last the route was almost entirely over snow. The ridges leading to the north and to the south from the summit of the Grand Cornier, exhibited in a most striking manner the extraordinary effects that may be produced by violent alternations of heat and cold. The southern one was hacked and split into the wildest forms; and the northern one was not less cleft and impracticable, and offered the droll piece of rock-carving which is represented upon page 211. Some small blocks actually tottered and fell before our eyes, and, starting others in their downward course, grew into a perfect avalanche, which descended with a solemn roar on to the glaciers beneath. [Illustration: PART OF THE SOUTHERN RIDGE OF THE GRAND CORNIER.]