I got an anthology of Tennyson out of the library and read the poem. It is rather fantastical. I can see a normal person staying up late to weave but not weaving night and day; it makes the point that the lady of Shalott is not a normal person in ordinary circumstances. I noticed she is cut off from the population yet somehow never runs out of yarn. Odd, that. If you like fairy tales, there is a tower and a knight and a mirror. The story comes from the Arthurian legends.
I also read The Princess and came across a couple of lines I recognized. A Handbook to Literature gives them as an example in its definition of alliteration. The Handbook cites the poem's author but no title. When I read the definition I'd been curious and wanted to see the lines in context, but never looked them up. I found the lines at the end of this segment:
Come down, O maid, from yonder mountain height....
So waste not thou, but come; for all the vales
Await thee; azure pillars of the hearth
Arise to thee; the children call, and I
Thy shepherd pipe, and sweet is every sound,
Sweeter thy voice, but every sound is sweet;
Myriads of rivulets hurrying thro' the lawn,
The moan of doves in immemorial elms,
And murmuring of innumerable bees.
–Tennyson, The Princess, part seventh