There's an old book from the 1800's called The Chimney Sweeper's Friend and Climbing Boy's Album that you can read on Google Books
and it contains some poetry (as well as a very harrowing section on accident case histories, and transcripts of parliamentary debates on banning the practice). I think that William Blake bit above might be from it. I might have a pop at finding a melody for it at some point. The tune from "The Blantyre Explosion" (as sung by the Ian Campbell Folk Group) immediately springs to mind as a possible fit.