Note FV — 1820
Reading edition
"The 'tributary stream,' which forms the subject of this sonnet, is the Tarn Beck, which rises in Seathwaite Tarn, and joins the Duddon just opposite Newfield. Seathwaite Chapel itself is not on the Duddon, but on the Tarn Beck. The sonnet gives a perfect description of its leading characteristics.
Mr. Chattock has given an etching of the Tarn." (Herbert Rix.)
"If one stands upon the Pen and looks up the Duddon Vale, the
Field or two of brighter green, or plot Of tillage-ground, that seemeth like a spot Of stationary sunshine:
will be seen, exactly described, upon the shoulder of the Fell that drops down from Heath Fell to the north-west. Is it possible that Wordsworth, as he gazed, was moved by
the flood Of yon pure waters, from their aëry height . . . that Torrent white,
just beneath the little upland farm with its emerald plot of tillage, shining like jewels in the July sun,
Hurrying, with lordly Duddon to unite,
—is it possible, I suggest, that Wordsworth was moved by this scene to write Sonnet XIX.?" (H. D. Rawnsley.)