How did a map stop cholera
In the 1850s an outbreak of cholera threatened London. Dr. John Snow, a British physician, mapped the deaths associated with the disease and determined that many deaths were occurring near one water pump. The pump handle was removed and the spread of the disease stopped. Prior to this time, the method by which cholera spread was unknown. Today, medical geographers and epidemiologists frequently use cartography to determine the cause and spread of disease or epidemics.