Most of you that took Geography, Cartography, or GIS courses remember reading about the story of Dr. John Snow and his map showing the cholera outbreak in Soho, London in 1854.

You also probably remember how he plotted cholera cases on the map and how he used that information to figure out that there was a strong spatial relationship between the cases and a polluted well on Broad Street, so he had the pump removed and the outbreak stopped. The map has been used as an example of the principles of GIS using layers of information and spatial relationships.

Well … despite it being a great story, unfortunately it’s not really how it played out. Both the use of the famous map and the story surrounding it have become somewhat modified through the passage of time. Click below to read the mythology of Snow’s cholera map.