London Cholera Epidemic 1854, MW
Heat map of Cholera cases in the Soho District of London 1854
This map displays the labor intensive discovery made by John Snow in 1854. By mapping all Cholera cases in Soho, Snow was able to identify the causative agent- the water pump located in dead center of the outbreak. From this discovery, the water pump was removed and Cholera was essentially erradicated. Additionally, John Snow played a vital role in the discovery that Cholera is a waterborne illness.