main navigation
my pace

Faculty & Staff

back to Faculty & Staff

Setter Spotlight: The Ghost Map

News Story

Dyson Assistant Professor Michael Finewood, PhD, has been drawing upon London's famous ghost map to teach students about the unlikely breakthroughs spurred by interdisciplinary research and critical thinking.

“In geography, what’s called the ghost map is pretty famous,” says Michael Finewood, PhD. “It’s a really early example of how people used a map to try and start understanding a problem.”

Finewood, an assistant professor of environmental studies and science at Dyson, has drawn upon this fascinating historical example to demonstrate the value of interdisciplinary research and learning—a value he has been fostering with both his Urban Environmental Geography students as well as in his own research.

While the ghost map doesn’t have anything to do with the paranormal, its development enabled a brilliant 19th century English physician named John Snow to help eradicate a pretty wicked demon that was tormenting nineteenth century industrial society. Cholera outbreaks were regularly killing hundreds of people in cities in part because the transmission was misunderstood. But Snow's research and persistent questioning helped discover the root cause of how cholera spread. By doing so—and by furthering scientists’ understanding as to how diseases can be tamed—he arguably enabled our great cities of the world to develop into the burgeoning centers of culture, industry, and human potential that we enjoy them as today.

“If you were looking at that point in time, industrial cities were new. There was a lot of poverty, and people were trying to figure that out—why are people poor? Very wealthy scientists and clergy were super critical of the working class. They blamed poverty on the community themselves. One of the things they often talked about was disease.”

Particularly in cities, disease often spread more quickly in poorer communities. For reasons we better understand today, this often had a lot to do with lack of waste management infrastructure, water supply contamination, and food cleanliness issues.

“One interesting piece is the prevailing belief at the time that the transfer of disease was through bad air, or miasma. People thought if you smelled foul smells—that was likely where disease existed.”

Enter John Snow, a physician who spent his life studying the way in which germs spread. Snow, as Finewood notes, was looking for an alternative explanation from the conventional, puritanical-leaning miasma explanation that more-or-less blamed the disease on the poor themselves.

Through his research Snow hypothesized that Cholera was not communicable through bad air, but rather water.

“Nobody believed him. He would write articles and be lambasted—the scientists of the day were convinced that miasma was the explanation. The problem was, to test this theory out, there needed to be an outbreak. He had to be very opportunistic.”

As he was developing this theory, a particular bad cholera outbreak occurred in the Soho neighborhood of London, right where he was setting up shop.

“Whole houses of people would die. People don’t want to go outside, things are pretty traumatic. And this guy is so convinced in what he’s doing, that he’s going out into the field.”

From here, Snow puts on the hats of part sociologist, part urban geographer, and part investigative journalist. He interviews entire houses, traces their water sources, and proceeds to map the 13 public wells and all the known cholera deaths. He noted that a number of cases seemed to stem from a water pump at the southwest corner of the intersection of Broad and Cambridge Streets. Putting back on his scientist hat, he examined water samples, and confirmed that this was indeed the source of the disease.

Snow put a dot on a nieghborhood map to represent each Cholera death in SoHo, and then used spatial analysis to determine the water source. 


While the city officials were initially skeptical, Snow uncovered a number of anomalies that cemented his hypothesis. A large workhouse just north of the well site suffered very few deaths even though it was in close proximity to the pump. Snow discovered that they had their own well where many residents would source their water from. A nearby brewery emerged unscathed because its workers would drink the brewery’s beer, and the fermentation process killed the bacteria.

Eventually, the water pump was shut off, and the cholera outbreak was quelled.

“A lot of science is done remotely. People look from afar and make decisions. But Snow (and a local partner) actually did fieldwork. You see geography, sociology, and epidemiology all come together. He was able to figure out, ‘look at all these dots,’ and located the pump. And went to the city and told them ‘we need to shut down this pump.’”

Ultimately, Finewood views this story as a fascinating convergence of circumstance, academic discipline, and historical development, all of which necessitated carefully crafted problem-solving. Snow's work eventually helped to shift the blame away from poverty, and led to the development of the vast water infrastructure stystems we have today. And while the ghost map breakthrough occurred 165 years ago, cities today are grappling with numerous issues that require similarly creative interdisciplinary solutions. This is something Finewood stresses to his current students, that these types of skills arguably become more and more in demand as the convergence of technology, urban development, and environmental hazards create unforeseen issues that our current knowledge hasn't yet considered.

“This is the direction we’re going in class and in my research. If you take an area like the Bronx, [it] has high levels of asthma. If you look historically at things like how Robert Moses built highways through the city that increased road traffic and fragmented neighborhoods—people who lived there lost social capital, got reduced air quality due to environmental and spatial change—that’s a modern day example that comes right out of that John Snow playbook. History, geography, sociology, and epidemiology all help to understand what is going on.”

Thanks to Finewood dipping into a fascinating historical example, Pace students will be more prepared to address the unique challenges of the 21st century.

Interestd in learning more? Feel free to reach out to Professor Finewood at You can also check out the book, The Ghost Map, by Steven Johnson, at Pace's Library