An old guide with whom I talked, who had lived in and about the canon for twenty-six years, said, "While we have been sitting here, the canon has widened and deepened"; which was, of course, the literal truth, the mathematical truth, but the widening and deepening could not have been apprehended by human sense. Our little span of human life is far too narrow for us to be a witness of any of the great earth changes. These changes are so slow,--oh, so slow,--and human history is so brief. So far as we are concerned, the gods of the earth sit in council behind closed doors. All the profound, formative, world-shaping forces of nature go on in a realm that we can reach only through our imaginations. They so far transcend our human experiences that it requires an act of faith to apprehend them. The repose of the hills and the mountains, how profound! yet they may be rising or sinking before our very eyes, and we detect no sign. Only on exceptional occasions, during earthquakes or volcanic eruptions, is their dreamless slumber rudely disturbed. Geologists tell us that from the great plateau in which the Grand Canon is cut, layers of rock many thousands of feet thick were cut away before the canon was begun. Starting from the high plateau of Utah, and going south toward the canon, we descend a grand geologic stairway, every shelf or tread of which consists of different formations fifty or more miles broad, from the Eocene, at an altitude of over ten thousand feet at the start, across the Cretaceous, the Jurassic, the Triassic, the Permian, to the Carboniferous, which is the bottom or landing of the Grand Canon plateau at an altitude of about five thousand feet. Each step terminates more or less abruptly, the first by a drop of eight hundred feet, ornamented by rows of square obelisks and pilasters of uniform pattern and dimension, "giving the effect," says Major Dutton, "of a gigantic colonnade from which the entablature has been removed or has fallen in ruins." The next step, or platform, the Cretaceous, slopes down gradually or dies out on the step beneath it; then comes the Jurassic, which ends in white sandstone cliffs several hundred feet high; then the Triassic, which ends in the famous vermilion cliffs thousands of feet high, most striking in color and in form; then the Permian tread, which also ends in striking cliffs, with their own style of color and architecture; and, lastly, the great Carboniferous platform in which the canon itself is carved. Now, all these various strata above the canon, making at one time a thickness of over a mile, were worn away in Pliocene times, before the cutting of the Grand Canon began. Had they remained, and been cut through, we should have had a chasm two miles deep instead of one mile.