For nearly a century, victorian London relied on "Climbing boys"--orphans owned by chimney sweeps--to clean flues and protect homes from fire. The work was hard, thankless and brutally dangerous. Eleven-year-old nan spar...For nearly a century, victorian London relied on "Climbing boys"--orphans owned by chimney sweeps--to clean flues and protect homes from fire. The work was hard, thankless and brutally dangerous. Eleven-year-old nan sparrow is quite possibly the best climber who ever lived--and a girl.