A light canoe of bark, containing a single human figure, moved swiftly up one of the twin streams that form the Ohio. The water, clear and deep, coming through rocky soil, babbled gently at the edges, where it lapped the land, but in the center the full current flowed steadily and without noise. The thin shadows of early dusk were falling, casting a pallid tint over the world, a tint touched here and there with living fire from the sun, which was...