We found no great difficulty in reaching the bottom of the hollow as before, and were now sufficiently calm to survey it with some attention. It was, indeed, one of the most singular-looking places imaginable, and we could scarcely bring ourselves to believe it altogether the work of nature. The pit, from its eastern to its western extremity, was about five hundred yards in length, when all its windings were threaded; the distance from east to west in a straight line not being more (I should suppose, having no means of accurate examination) than forty or fifty yards. Upon first descending into the chasm, that is to say, for a hundred feet downward from the summit of the hill, the sides of the abyss bore little resemblance to each other, and, apparently, had at no time been connected, the one surface being of the soapstone, and the other of marl, granulated with some metallic matter. The average breadth or interval between the two cliffs was probably here sixty feet, but there seemed to be no regularity of formation. Passing down, however, beyond the limit spoken of, the interval rapidly contracted, and the sides began to run parallel, although, for some distance farther, they were still dissimilar in their material and form of surface. Upon arriving within fifty feet of the bottom, a perfect regularity commenced. The sides were now entirely uniform in substance, in colour, and in lateral direction, the material being a very black and shining granite, and the distance between the two sides, at all points facing each other, exactly twenty yards. The precise formation of the chasm will be best understood by means of a delineation taken upon the spot; for I had luckily with me a pocketbook and pencil, which I preserved with great care through a long series of subsequent adventure, and to which I am indebted for memoranda of many subjects which would otherwise have been crowded from my remembrance.