in Thoreau’s Journal:

From this hilltop I overlook, again bare of snow, putting on a warm, hazy spring face, this seemingly concave circle of earth, in the midst of which I was born and dwell, which in the northwest and southeast has a more distant blue rim to it, as it were of more costly manufacture. On ascending the hill next his home, every man finds that he dwells in a shallow concavity whose sheltering walls are the convex surface of the earth, beyond which he cannot see. I see those familiar features, that large type, with which all my life is associated, unchanged.