b'There is a slumbering subterranean fire in nature which never goes out, and which no cold can chill. What fire could ever equal thesunshine of a winters day, when the meadow mice come out by the wallsides, and the chicadee lisps in the defiles of the wood? The warmth comes directly from the sun, and is not radiated from the earth, as in summer; and when we feel his beams on our backs as we are treading some snowy dell, we are grateful as for a special kindness, and bless the sun which has followed us into that by-place.Henry David Thoreau, A Winter Walk (a meditative meandering by the 25-year-old American essayist)'