There is a slumbering subterranean fire in nature which never goes out, and which no cold can chill. It finally melts the great snow, and in January or July is only buried under a thicker or thinner covering. In the coldest day it flows somewhere, and the snow melts around every tree. This field of winter rye which sprouted late in the fall and now speedily dissolves the snow is where the fire is very thinly covered. We feel warmed by it. In the winter warmth stands for all virtue, and we resort in thought to a trickling rill, with its bare stones shining in the sun, and to warm springs in the woods, with as much eagerness as rabbits and robins. The steam which rises from swamps and pools is as dear and domestic as that of our own kettle. What fire could ever equal the sunshine of a winter's day, when the meadow-mice come out by the wall-sides, and the chickadee 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. This subterranean fire has its altar in each man's breast, for in the coldest day, and on the bleakest hill, the traveler cherishes a warmer fire within the folds of his cloak than is kindled on any hearth. A healthy man, indeed, is the complement of the seasons, and in winter summer is in his heart. There is the South. Thither have all birds and insects migrated, and around the warm springs in his breast are gathered the robin and the lark. At length, having reached the edge of the woods and shut out the gadding town, we enter within their covert as we go under the roof of a cottage, and cross its threshold, all ceiled and banked up with snow. They are glad and warm still, and as genial and cheery in winter as in summer. As we stand in the midst of the pines, in the flickering and checkered light which straggles but little way into their maze, we wonder if the towns have ever heard their simple story. It seems to us that no traveler has ever explored them, and notwithstanding the wonders which science is elsewhere revealing every day, who would not like to hear their annals? Our humble villages in the plain are their contribution. We borrow from the forest the boards which shelter and the sticks which warm us. How important is their evergreen to the winter, that portion of the summer which does not fade, the permanent year, the unwithered grass. Thus simply and with little expense of altitude is the surface of the earth diversified. What would human life be without forests, those natural cities? From the tops of mountains they appear like smooth-shaven lawns; yet whither shall we walk but in this taller grass?