In the intaglio etching below, copied after Collings, Blake has left us a picture of May Day festivities in 18th-century London.
The small figure at the lower right-center of the engraving, is one of the climbing boys. Ackroyd quotes Southey, who witnessed one of the May Day festivals some years after Blake's depiction:
[The sweepers] clothes seemed as if they had been dragged through the chimney, as indeed had been the case, and these sooty habiliments were bedecked with pieces of foil, and with ribbons of all gay characters, flying like streamers in every direction as they whisked around: their sooty faces were reddened with rose-pink, and in the middle of each cheek was a patch of gold leaf, the hair was frizzed out, and as white as powder could make it ... and in like manner ornamented with ribbons, and foil, and flowers. (Ackroyd, pp. 123-24)This one day of the year, the chimney sweeps were freed from their miserable occupation, and took a place at the center of London's dizzying whirl. It must have seemed peculiarly dreamlike to the city's inhabitants, to see these figures from the margins of their economy scamping with milkmaids, rouged and coiffed and tricked out like enfants from the French court. And dreamlike, it may have been a mechanism by which the society revealed to itself, in a cloaked carnival atmosphere, its repressed corporate guilt over the sweepers' plight. They were, after all, an indispensable (though individually, easily replaced) part of the city's viability.
In little Tom's dream, the "Angel" with the "bright key" becomes the mythic extension of the speaker's "Hush Tom never mind it." The only key that can turn the wards of the "black coffins" is held by the Angel of Death. The consolation of the dream, a promise of "fresh aire and green champaign" is, like the consolation offered for Tom's shorn head, an instrument of psychic repression in which a loss of life and delight temporarily displaces the heavy weight of Tom's intelligible world.
The irony is heightened by a shift of tense at the third line: "Then down a green plain leaping laughing they run / And wash in a river and shine in the Sun." These are the lines Blake illustrates at the foot of the plate. There's no doubt that Blake believed death to be a passage into joyousness, but the "death" offered in the dream is sheer innocence, and translates into Tom's experience as acquiescence to his sacrifice.