in Thoreau’s Journal:
Under the waves of the snowy ocean yesterday, roads and rivers, pastures and cultivated fields, all traces of man’s occupancy of the globe were for the most part concealed. Water and sand also assume this same form under the influence of wind. And I have seen, on the surface of the Walden ice, great sweeping, waving lines, somewhat like these. It is the track of the wind, the impress which it makes on flowing materials.