How did people wake up before alarm clocks? Well, during the Industrial Revolution in England and Ireland, one method was a “Knocker-up.” Knocker-ups were people who were paid to go around to houses and tap on doors or windows of their clients until they woke up. Young people unfit to work in the factories or the elderly were most often employed as knocker-ups. They usually used long sticks to tap on upper floor windows, or in at least one case, a pea shooter. They would not leave until they were sure their client had been awoken at the time previously agreed upon, often by a chalk time written on the front door. Some factories or mills hired their own knocker-ups to make sure all their employees got to work on time. The job fell out of fashion as soon as alarm clocks were more reliable.