February 10, 1860 in Thoreau’s Journal:

I do not know of any more exhilarating walking than up or down a broad field of smooth ice like this in a cold, glittering, winter day….

February 10, 1841

I asked a man to-day if he would rent me some land, and he said he had four acres as good soil “as any outdoors.” It was a true poet’s account of it. He and I, and all the world, went outdoors to breathe the free air and stretch ourselves. For the world is but outdoors, – and we duck behind a panel.

February 10, 1860

In the cold, clear, rough air from the northwest we walk amid what simple surroundings! Surrounded by our thoughts or imaginary objects, living in our ideas, not one in a million even sees the objects which are actually around him.