Next my attention was attracted to a number of objects lying upon the platform immediately west of us. One of these appeared to be a steel bowl-like container some thirty feet deep and a hundred in diameter, like the storage tanks used in oil fields. Nearby was an open tank measuring perhaps fifty feet in each dimension, and beside this were the most startling of all--several hundred foot pieces of built-up structural steel resembling knife, fork and spoon. In retrospect, the deduction from this evidence was obvious, but as we stared down at this spectacle, a sort of numbness took hold of our minds. As a later comparison of impressions verified, none of us came remotely near guessing the truth in those incredible seconds. For what seemed like minutes we just stared, and then the spell was broken. Walt had squeezed in beside me, where he gave vent to a low whistle of amazement. Baker shushed him, and then shifted to a better position, in so doing knocking a rock from the ledge. This started a small avalanche which went clattering down the cliff with a sound, to our hypersensitive ears, like thunder. We all froze in our places, abruptly aware that the moon illuminated us like actors in a spotlight. For a good minute we waited tense, and then gradually relaxed. Baker started to say something when without warning the ground beneath us shook, starting a score of rockslides. We recoiled from the edge and braced for a stronger earthquake shock. Then suddenly Baker uttered a hoarse cry. He was pointing--pointing down into the blackness at our feet where our eyes had as yet been unable to penetrate. Something was there, something vast and dim and shapeless like a half inflated airship. Then a part of it was detached and came up almost to our level. It moved too rapidly for any detail to be seen--our only impression was of a vast white column large as the Washington monument which swung up into the moonlight and then was withdrawn. At the same time the ground quivered anew, starting fresh slides. We blinked stupidly for several seconds, and then became conscious for the first time of the sound. It was like a vast cavernous wheeze at first, and then a series of distinct wet thuds followed by a prolonged gurgling rumble. If these descriptive phrases sound strange and awkward, let me give assurance that they are as nothing to the eerie quality of the noises themselves. We lay glued to our rocky perch, hardly daring to breathe, until the last windy sigh had died away. Baker found his voice first. "Good God, it's something alive!" Chamberlin tried to reason. "It can't be--why, it's two hundred feet high--it's just a gas bag, like Stimson said. It's--"