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Era: Thematic & Scientific Revolution·Cartographer: Dr. John Snow (Engraved by C.F. Cheffins)·Year: 1854·Public Domain
Dr. John Snow’s Cholera Dot Map of Soho (1854)
"The foundational map of spatial epidemiology proving the waterborne origin of cholera"
During the September 1854 cholera outbreak in Soho, London, Dr. John Snow plotted each cholera death as a black bar stacked at the victim's street address. The spatial clustering revealed that deaths concentrated around the Broad Street water pump.
Interactive Specimen Pan & ZoomAccession: Wellcome Library No. 562140i
Orientation: North-Up
380 × 330 mm
Dr. John Snow (Engraved by C.F. Cheffins)·1854·Wellcome Collection, London / Library of Congress
ZOOM: 100%Repository Archive
Notable Cartographic Signatures
- Black bars representing deaths stacked outside residential doorways
- Broad Street pump situated at the exact geometric center of death clusters
- Voronoi-like walking distance polygons showing the pump was the closest water source
The Rhetorical & Ideological Argument
"Cholera is not transmitted through airborne 'miasma' or moral degeneracy; it is a waterborne pathogen whose source can be proven by spatial clustering around contaminated infrastructure."
Explicit Features
- Black bars representing deaths stacked outside residential doorways
- Broad Street pump situated at the exact geometric center of death clusters
- Voronoi-like walking distance polygons showing the pump was the closest water source
Intentional Omissions
- Architectural floor plans and socio-economic demographics
Physical Specimen & Geodesy
Projection:
Planar Urban Cadastral Map
Orientation Axis:
North-Up
Physical Medium:
Lithographic street map with hand-drawn black death bars
Original Physical Dimensions:
380 × 330 mm
Custodial Repository:
Wellcome Collection, London / Library of Congress
Accession: Wellcome Library No. 562140i
Interdisciplinary Context & Connections
VeridianumFOUNDS
Public Health Spatial Outbreak Tracking
MorphologiumAPPLIES
Voronoi Spatial Catchment Partitioning
Academic Provenance: Snow, J. (1855)