Underlying this country, nine hundred feet below the highest ridgetops, more than four hundred feet below the surface of the river, is sea level. We seldom think of it here; we are a long way from the coast, and the sea is alien to us. And yet the attraction of sea level dwells in this country as an ideal dwells in a man’s mind. All our rains go in search of it and, departing, they have carved the land in a shape that is fluent and falling.
