gray-blue smoke, while the recesses of the pines looked like the lair
of Night. Beyond the District limits we struck the Marlborough pike,
which, round and hard and white, held squarely to the east and was
visible a mile ahead. Its friction brought up the temperature amazingly
and spurred the pedestrians into their best time. As I trudged along,
Thoreau's lines came naturally to mind:--

"When the spring stirs my blood
With the instinct of travel,

I can get enough gravel
On the old Marlborough road."

Cold as the day was (many degrees below freezing), I heard and saw
bluebirds, and as we passed along, every sheltered tangle and overgrown
field or lane swarmed with snowbirds and sparrows,--the latter mainly
Canada or tree sparrows, with a sprinkling of the song, and, maybe, one
or two other varieties. The birds are all social and gregarious in
winter, and seem drawn together by common instinct. Where you find one,
you will not only find others of the same kind, but also several
different kinds. The regular winter residents go in little bands, like
a well-organized pioneer corps,--the jays and woodpeckers in advance,
doing the heavier work; the nuthatches next, more lightly armed; and
the creepers and kinglets, with their slender beaks and microscopic
eyes, last of all. [Footnote: It seems to me this is a borrowed
observation, but I do not know to whom to credit it.]

Now and then, among the gray and brown tints, there was a dash of
scarlet,--the cardinal grosbeak, whose presence was sufficient to
enliven any scene. In the leafless trees, as a ray of sunshine fell