The diversity of light and shade upon the swells and depressions at the hour of sunrise, or when at midday clouds are drifting along the sky, is endless. A few points here and there are thrown into prominent relief; while others, deeply retreating, constitute an imaginary back-ground perfect in its kind. And then the sunlight, constantly changing its position, is received upon such a variety of angles, and these, too, so rapidly vary as the breeze rolls over the surface, that it gives the scene a wild and shifting aspect to the eye at times, barely reconcilable with the idea of reality. As the sun reached the meridian the winds went down, and then the stillness of death hung over the prairie. The utter desolateness of such a scene is indescribable. Not a solitary tree to intercept the vision or to break the monotony; not a sound to cheer the ear or relieve the desolation; not a living {94} thing in all that vast wild plain to tell the traveller that he was not "Alone, alone, all, all alone, Alone on a wide, wide sea!" It is at such a season that the question presents itself with more than ordinary vehemence to the mind, _To what circumstance do these vast prairies owe their origin_? Amid what terrible convulsion of the elements did these great ocean-plains heave themselves into being? What mighty voice has rolled this heaped-up surface into tumult, and then, amid the storm and the tempest, bid the curling billows stand, and fixed them there? "The hand that built the firmament hath heaved And smooth'd these verdant swells."