How long would it take a school-inspector of average activity to tumble head over heels from London to York?

How long would it take a school-inspector of average activity to tumble head over heels from London to York?

一个负责日常活动的学校督学要花多长时间才能从伦敦一头栽到约克?

-- Charles Kingsley 查尔斯·金斯利