Various, Harper's Young People, September 5…
“ Look up into the bright blue sky, and then down at the solid earth beneath your feet—you do not find any difficulty in telling, without taking a moment to think, which is sky and which is earth; but if you are so happy as to live in the wide open country, or near the sea, or on a lofty hill, look off and off and off until you see only the delicate blue haze, like smoke, which divides the heavens from the earth. ”
