in Thoreau’s Journal:

Methinks the reflections are never purer and more distinct than now at the season of the fall of the leaf, just before the cool twilight has come, when the air has a finer grain. Just as our mental reflections are more distinct at this season of the year, when the evenings grow cool and lengthen and our winter evenings with their brighter fires may be said to begin. And painted ducks, too, often come and sail or float amid the painted leaves.