I was a new man, but the thought of my brother dying in the air ship came upon me with renewed force. Could I ever hope to find him? The heights above offered the only chance of doing so, for there I could overlook the inequalities of the sand hills, discover his position, and with carefully established bearings reach the spot. It was a frightful undertaking, but my only hope. Hanging the cask with its remains of food and water across my back by the cords attached, I again pushed forward, and after an hour’s patient trudging was relieved to find the sand less tenacious, and far more shallow; in fact, the walking had become comparatively easy, but the climb had not commenced. When it did I discovered what appeared to be a natural rocky way leading above. Up this dangerous path I directed my steps, and although the work was steep and laborious, it was a relief to have solid ground once more beneath my feet. At the end of two hours I had ascended to a great elevation, but to my amazement the air ship was not yet visible. The atmosphere over the plain was quivering with heat, and its dense gaseous condition may have obscured the vessel, but I was greatly distressed that it had not come in view. Another hour’s climb and still the noble craft was hidden from my sight. It was growing cooler, but neither watercourse nor vegetation had been encountered, yet the black, towering rocks closed in upon me on every side. Whither was the path leading, and what would be the end? It would be useless to return, to be lost in the drift. There was but one object to steer by, and but one hope to which I could cling, and that was the great barren rock that supported me. If once my back was turned upon this single landmark, there was absolutely nothing to look to. And so with aching heart, and the gravest misgivings, I struggled on, stopping constantly to search the plain below. So far the path had been narrow and tortuous, a mere rut, twisting in and out among the irregularities of the wall, but suddenly I found myself standing upon a horizontal ledge, like a natural piazza overlooking the plain. On my right, at the back of this landing, the cliff continued to rise in a sheer ascent of perhaps a hundred feet, and here I again observed those dark openings, which I had seen from below. It was a remarkable formation, and I walked along it with an uncanny dread lest here was the abode of some unknown being which might resent my intrusion.