The forces that did all this vast delving and sculpturing—­the air, the rains, the frost, the sunshine—­are as active now as they ever were; but their activity is a kind of slumbering that rarely makes a sign.  Only at long intervals is the silence of any part of the profound abyss broken by the fall of loosened rocks or sliding talus.  We ourselves saw where a huge splinter of rock had recently dropped from the face of the cliff.  In time these loosened masses disappear, as if they melted like ice.  A city not made with hands, but as surely not eternal in the earth!  In our humid and severe Eastern climate, frost and ice and heavyrains working together, all these architectural forms would have crumbled long ago, and fertile fields or hill-slopes would have taken their place.  In the older Hawaiian Islands, which probably also date from Tertiary times, the rains have carved enormous canons and amphitheatres out of the hard volcanic rock, in some places grinding the mountains to such a thin edge that a man may literally sit astride them, each leg pointing into opposite valleys.  In the next geologic age, the temples and monuments of the Grand Canon will have largely disappeared, and the stupendous spectacle will be mainly a thing of the past.

It seems to take millions of years to tame a mountain, to curb its rude, savage power, to soften its outlines, and bring fertility out of the elemental crudeness and barrenness.  But time and the gentle rains of heaven will do it, as they have done it in the East, and as they are fast doing it in the West.

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.