{"id":1197,"date":"2016-03-06T22:58:08","date_gmt":"2016-03-06T22:58:08","guid":{"rendered":"http:\/\/blogs.lincoln.ac.nz\/gis\/?p=1197"},"modified":"2023-05-07T04:07:37","modified_gmt":"2023-05-07T04:07:37","slug":"cholera-spatial-thinking-and-john-snow-soho-1854","status":"publish","type":"post","link":"https:\/\/blogs.lincoln.ac.nz\/gis\/cholera-spatial-thinking-and-john-snow-soho-1854\/","title":{"rendered":"Cholera, Spatial Thinking and John Snow: Soho 1854"},"content":{"rendered":"

A particularly bad outbreak of cholera in Soho in 1854 led one man to identify\u00a0contaminated water as the mode\u00a0of transmission and apply\u00a0<\/span>one of the most famous instances of spatial thinking.<\/em><\/p>\n

At a time when the fledgling Canterbury colony was getting itself sorted out,\u00a0the London of 1854 was a stinking, festering hell-hole.\u00a0 Growing from the tiny Roman town of Londinium, through the medieval ages and then in to a city of over two million souls, the place\u00a0was overrun by filth.\u00a0 Sewage flowed freely in the street and abattoirs operated down mews and alleyways, blood and gore washed away with each rain.\u00a0 The Thames, a source of drinking water for many, was little more than an open sewer.<\/p>\n

\"The_silent_highwayman\"<\/a>
The Silent Highwayman. Source: Wikipedia Commons<\/figcaption><\/figure>\n

To deal with human waste, buildings and homes tended to have cesspits in their basements (which I won’t show you any pictures of), which were periodically emptied by the lower echelons of society, and conveniently disposed of\u00a0in the Thames.<\/p>\n

At the time, London’s sewer system was limited and water for drinking and washing was piped to public water pumps on street corners, often straight from the river.\u00a0 Not alone amongst European cities, cholera<\/a> was an ongoing problem, having already suffered through recent\u00a0outbreaks where well over 10,000 people were killed.<\/p>\n

\"752px-Punch-A_Court_for_King_Cholera\"<\/a>
Source: Stephen J. Lee: Aspects of British Political History, 1815\u20131914. Routledge, London\/New York 1994, ISBN 0-415-09007-5, Fig. 24.<\/figcaption><\/figure>\n

There’s nothing pleasant about cholera – it’s a horrible way to die. \u00a0Symptoms include severe diarrhea and vomiting leading to irreversible dehydration. \u00a0Once contracted, a person can die within painfully slow hours to days.<\/p>\n

At that time, no one had a clear understanding of how the disease was transmitted.\u00a0 The predominant idea was that it was air-bourne, a miasma<\/a> that seeped up from underground.\u00a0 After all, as the city grew beyond its Roman city walls, it expanded over cemeteries and offal pits, many of which contained bodies of those killed\u00a0by the Black Death<\/a>. \u00a0Most efforts at controlling cholera focused on air quality.\u00a0 But some were skeptical of that notion, and one John Snow<\/a> in particular.<\/p>\n

\"Snow\"<\/a>
By The original uploader was Rsabbatini at English Wikipedia [CC BY 4.0 (http:\/\/creativecommons.org\/licenses\/by\/4.0)], via Wikimedia Commons<\/figcaption><\/figure>A physician and anaesthetist (to the Queen, no less), he had already tied Thames water to outbreaks<\/a>, but not many paid attention.\u00a0 He was actively investigating water as a mode\u00a0of transmission when a particularly bad outbreak occurred in Soho<\/a>, west London.\u00a0 Over the course of three days, over 500 people died, and he wanted to know why.<\/p>\n

So he talked to people in Soho and looked in detail at the records of deaths.\u00a0 This record contained basic information about each person; name, age, and address, amongst other things (an analog spreadsheet of sorts).\u00a0 As part of his investigations, he did something which these days we might think obvious – he translated the deaths in the record book on to a map and looked for any patterns.\u00a0 Here’s a copy of that map:<\/p>\n

\"Snow-cholera-map-1\"<\/a>
By John Snow – Published by C.F. Cheffins, Lith, Southhampton Buildings, London, England, 1854 in Snow, John. On the Mode of Communication of Cholera, 2nd Ed, John Churchill, New Burlington Street, London, England, 1855.<\/figcaption><\/figure>\n

On this map, he plotted the number of deaths occurring at an address as a sort of stack of small rectangles: the more deaths, the longer\u00a0the stack. Our human wetware can look at this and fairly easily pick up a sort of pattern, a clustering of deaths around a point. \u00a0Here’s a bit of detail from the map:<\/p>\n

\"Snow-cholera-map-1-detail\"<\/a><\/p>\n

And roughly at the centre of this cluster sat a public water well. \u00a0Armed with these insights, Snow was able to convince the town officials to remove the handle of the pump to prevent its use, and the new cases of cholera dropped off almost immediately.<\/p>\n

Later investigations showed\u00a0that the pipe feeding the water pump had become damaged and the contents of a cesspit from an adjacent house had been leaking directly into the water line – \u00a0a baby had recently died from cholera at that house.\u00a0 People were essentially drinking cholera contaminated raw sewage.<\/p>\n

An\u00a0interesting thing to note – there were relatively few deaths at the large workhouse just to the north of the water pump, even though everyone living and working there got their water from the same source. \u00a0Why so few? \u00a0It was a brewery. \u00a0The brewing process effectively killed off the cholera bacteria and is a great way to purify contaminated water (as our FESD dean will no doubt agree) practised over centuries.<\/p>\n

Several important things follow from this event.\u00a0 First, the connection between contaminated water and cholera was established, setting the scene for not just London, but many other cities around the world, to undertake huge public works projects to build\u00a0reticulated water and sewer systems and transforming the sanitary conditions for city dwellers – some would argue that this was the beginning of modern cites as we know them.\u00a0 Secondly, the fledgling science of modern epidemiology got its start from Snow and his investigations.\u00a0 Thirdly (and most pertinently here), this is a great example of spatial thinking.\u00a0 Any GIS course that doesn’t mention Snow is likely doing a disservice to its students (IMHO).\u00a0 Geographers from around the world will still make a pilgrimage to the water pump monument on the corner of what is now Broadwick and\u00a0Poland\u00a0Streets to pay tribute to this event (your humble author included).<\/p>\n

\"DSCN3810\"<\/a><\/p>\n

\"DSCN3811\"<\/a>
Photos: C. Doscher, 2013<\/figcaption><\/figure>\n

Incidentally, the original water pump was on the corner of Broad and Lexington Streets, where the John Snow pub<\/a> now stands.<\/p>\n

(If you make it there yourself, be sure to call in to Flat White<\/a>, just around the corner in Berwick Street for a proper cup of coffee, New Zealand style.)\u00a0<\/em><\/p>\n

This is a great example of how incorporating location into your investigations (spatial thinking) can provide you with additional insights.\u00a0 Spatial thinking is another arrow in your quiver of methods to understand phenomena.\u00a0 Not all problems will have a spatial component but for those that do, spatial thinking (and GIS) are a great\u00a0tool at your disposal.<\/p>\n

This is\u00a0also a great example of using a map to communicate information, to tell your story.\u00a0 For many, Snow’s map was a compelling factor in convincing them of the connection between the water and the outbreak. \u00a0The simple act of mapping the deaths led to an\u00a0easier to grasp pattern than what could be gleaned from the spreadsheet of deaths. \u00a0In another post we’ll look at how we can work with Snow’s spatial data to meaningfully display them in different ways.<\/p>\n

Sadly, cholera remains a significant problem today, being especially a risk in areas of poor sanitation and often the number one concern after a natural disaster in populated areas. \u00a0Spatial thinking has helped to understand it but not necessarily to prevent it.<\/p>\n

I can heartily recommend a book from our library that gives you much more detail on this event: The Ghost Map<\/a> by Steven Johnson.\u00a0 Well worth a read.<\/p>\n

C<\/p>\n

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A particularly bad outbreak of cholera in Soho in 1854 led one man to identify\u00a0contaminated water as the mode\u00a0of transmission and apply\u00a0one of the most famous instances of spatial thinking. At a time when the fledgling Canterbury colony was getting itself sorted out,\u00a0the London of 1854 was a stinking, festering hell-hole.\u00a0 Growing from the tiny […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1197","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/posts\/1197","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/comments?post=1197"}],"version-history":[{"count":1,"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/posts\/1197\/revisions"}],"predecessor-version":[{"id":4149,"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/posts\/1197\/revisions\/4149"}],"wp:attachment":[{"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/media?parent=1197"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/categories?post=1197"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.lincoln.ac.nz\/gis\/wp-json\/wp\/v2\/tags?post=1197"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}