In 1854 a doctor removed a single pump handle and slowed a deadly cholera outbreak. In 1854, London was struck by a severe cholera outbreak that killed families within days. Most officials believed the disease spread through “bad air,” but physician John Snow suspected contaminated drinking water — a radical idea for the time. Snow mapped cholera cases in the neighborhood surrounding Broad Street and noticed they clustered around one public pump. He interviewed families, traced infection pattern

John Snow's original 1854 cholera outbreak map transformed into 3D. See it here: http://p.ctx.ly/r/9kjj #gis #gisday #gisday2019 | GIS Day