in Thoreau’s Journal:

As I stand looking over the river, looking from the bridge into the flowing, eddying tide, the almost strange chocolate-colored water, the sound of distant crows and cocks is full of spring. As Anacreon says “the works of men shine,” so the sounds of men and birds are musical.

Something analogous to the thawing of the ice seems to have taken place in the air. At the end of winter there is a season in which we are daily expecting spring, and finally, a day when it arrives….