The knocker-up: an alarm before the alarm clock

A knocker-up

In a time before alarm clocks became affordable and reliable, a knocker-up was hired to wake sleeping people so that they could get to work on time.

“The knocker-up used a truncheon or short, heavy stick to knock on the clients’ doors or a long and light stick, often made of bamboo, to reach windows on higher floors. The knocker-up would not leave a client’s window until they were sure that the client had been awoken.”

Source: https://en.wikipedia.org/wiki/Knocker-up