Analysis of A Rivulet

It is a lovely stream; its wavelets purl
As if they echoed to the fall and rise
Of the capricious breeze; each upward curl
That splashes pearl, mirrors the fairy eyes
Of viewless passer, and the billows hurl
Their sparkles on her lap, as over she flies.
And see, where onward whirls, within a ring
Of smoothest dimples, a dark foxglove bell
Half stifled by the gush encircling;
Perchance some tiny sprite crawled to that shell
To sleep away the noon, and winds did swing
Him into rest; for the warm sun was well
Shaded off by the long and silky down;
So I will save it, lest the elf should drown.