click area of map
       


Source: Snow J. On the Mode of 

Communication of Cholera, 1855.

This is Map 2 in John Snow's book. It

was used by Dr. Snow to describe the

grand experiment of 1854 comparing

cholera mortality among persons 

consuming contaminated water 

(Southwark and Vauxhall Company - 

blue, but faded to green on the map) 

versus cleaner water (Lambeth Company 

- red).  The overlapping area (purple but 

faded to gray-red on the map) is where 

John Snow analyzed the results of a 

natural experiment. The 1854 map is 

presented in 16 panels, sized 140-310 K. 



Last Updated

26 Aug 2006