How a map of dots found a cholera pump in 1854: John Snow and Broad Street
30seconds
In late August 1854, cholera tore through a few streets of Soho, killing roughly 600 people in weeks. Almost everyone blamed foul air. John Snow suspected the water, and he drew a map.
He marked each death at the house where it happened, and the marks bunched around the Broad Street pump. Then he asked about the exceptions: a workhouse and a brewery with their own wells, and far-off people who fetched the pump's water anyway.
Play detective in an invented neighbourhood: slide through the days, compare pumps, and decide which handle to pull.
Deep dive · 4 min
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