" Other sounds woke the hamlet: the blast of a ship's foghorn blown at the pit top to mark the start of the shift; the echo of others - 'buzzers', as they were called - from the pits in the valley below. For the deep sleepers, there was the 'knocker-up'; a human alarm clock, he used a long pole to rattle the window panes of the households that paid him a few pennies each week. "

― , Black Diamonds: The Rise and Fall of an English Dynasty