in Thoreau’s Journal:

….cold and dark….the landscape is barren of objects, the trees being leafless… Truly hard times, these! Not a mosquito left, not an insect to hum. Crickets gone into winter quarters. Friends long since gone there, and you left to walk on frozen ground with your hands in your pockets . Ah, but is not this a glorious time for your deep inward fires? ….Nothing but the echo of your steps on the frozen ground, which, it is true, is being prepared for immeasurable snows.

Still there are brave thoughts within you that shall remain to rustle the winter through, like white-oak leaves upon your boughs, or like shrub oaks that remind the traveler of a fire upon the hillsides, or evergreen thoughts, cold even in the midsummer by their nature. These shall contrast the more fairly with the snow….