Page:Personal Memoirs of Ulysses S. Grant Volume I.pdf/199

were but a few feet high from the floor; but the formation is going on constantly, and many centuries hence these stalagmites will extend to the ceiling and become complete columns. The stalagmites were all a little concave, and the cavities were filled with water. The water percolates through the roof, a drop at a time—often the drops several minutes apart—and more or less charged with mineral matter. Evaporation goes on slowly, leaving the mineral behind. This in time makes the immense columns, many of them thousands of tons in weight, which serve to support the roofs over the vast chambers. I recollect that at one point in the cave one of these columns is of such huge proportions that there is only a narrow passage left on either side of it. Some of our party became satisfied with their explorations before we had reached the point to which the guides were accustomed to take explorers, and started back without guides. Coming to the large column spoken of, they followed it entirely around, and commenced retracing their steps into the bowels of the mountain, without being aware of the fact. When the rest of us had completed our explorations, we started out with our guides, but had not gone far before we saw the torches of an approaching party. We could not conceive who these could be, for all of us had come in together, and there were none but ourselves at the entrance when