Two days earlier Keats had copied out in his letter for America, side by side with the words for a commonplace operatic chorus of the _Fairies of the Four Elements_, and as though it were of no greater value, that masterpiece of romantic and tragic symbolism on the wasting power of Love, _La Belle Dame sans Merci_. This title had already been haunting Keats's imagination when he wrote the _Eve of St Agnes_. He calls by it the air to which Porphyro touches his lute beside the sleeping Madeline. It is the title of a cold allegoric dialogue of the old French court poet Alan Chartier, which Keats knew in the translation traditionally ascribed to Chaucer. But except the title, Keats's new poem has nothing in common with the French or the Chaucerian _Belle Dame_. The form, the poetic mould, he chooses is that of a ballad of the 'Thomas the Rhymer' class, in which a mortal passes for a time into the abode and under the power of a being from the elfin world. Into this mould Keats casts--with suchlike imagery he invests--all the famine and fever of his private passion, fusing and alchemising by his art a remembered echo from William Browne, 'Let no bird sing,' and another from Wordsworth, 'Her eyes are wild,' into twelve stanzas of a new ballad music vitally his own and as weirdly ominous and haunting as the music of words can be. The metrical secret lies in shortening the last line of each stanza from four feet[11] to two, the two to take in reading the full time of four, whereby the movement is made one of awed and bodeful slowness--but let us shrink from the risk of laying an analytic finger upon the methods of a magic that calls to be felt, not dissected. Known as it is by heart to all lovers of poetry, I will print the piece again here, partly for the reason that in some of the most accessible and authoritative recent editions it is unfortunately given with changes which rob it of half its magic:-- O what can ail thee, knight-at-arms Alone and palely loitering? The sedge is withered from the lake, And no birds sing! O what can ail thee, knight-at-arms So haggard and so woe-begone? The squirrel's granary is full, And the harvest's done. I see a lily on thy brow, With anguish moist and fever dew; And on thy cheek a fading rose Fast withereth too-- I met a lady in the meads Full beautiful, a faery's child; Her hair was long, her foot was light, And her eyes were wild-- I made a garland for her head, And bracelets too, and fragrant zone; She looked at me as she did love, And made sweet moan-- I set her on my pacing steed, And nothing else saw all day long; For sideways would she lean, and sing A faery's song-- She found me roots of relish sweet, And honey wild, and manna dew; And sure in language strange she said, I love thee true--