in Thoreau’s Journal:

Up river on ice to Fairhaven Pond…The air is fresher & the sky clearer in the morning –– We have this morning the clear cold continent sky of January. The river is frozen solidly & I do not have to look out for openings. Now I can take that walk along the river highway & the meadow––which leads me under––the boughs of the maples & the swamp white oaks &c which in summer overhang the water––there I can now stand at my ease & study their phenomena––amid the sweet gale & button bushes projecting above the snow & ice.  I see the shore from the water side––  A liberal walk––so level & wide & smooth without under brush.