Imagine life without alarm clocks. Workdays would start at noon, breakfast would be brunch, and no one would make it to class before the first bell. From the early 1800s through the 1960s, factory workers didn’t have much of a choice. To get to work on time, they relied on “knocker-uppers,” aka, human alarm clocks. Using long bamboo sticks, or peashooters, Britain’s knocker-uppers would stroll down the streets rapping at windows to help their patrons kick-start their days.