Dan Snow's History Hit - The Great Caterpillar Outbreak of 1782

Episode Date: September 12, 2023

In the spring of 1782, it wasn't the American Revolutionary War that had Londoners worried. The city and nearby countryside had been covered in ominous, mysterious webs, filled with untold numbers of caterpillars and their eggs. The city responded with panic, and rumours of plague and pestilence spread like wildfire. It seems far-fetched that an insect like the brown-tail moth could begin a citywide crisis; so why were Londoners so concerned? And how did the caterpillars become scapegoats for the city's recent tensions?Dan is joined by John Lidwell-Durnin, a lecturer in the History of Science at Exeter University, to delve into the bizarre history of the 1782 caterpillar outbreak.Produced by James Hickmann and edited by Dougal Patmore.Discover the past on History Hit with ad-free original podcasts and documentaries released weekly presented by world-renowned historians like Dan Snow, Suzannah Lipscomb, Lucy Worsley, Matt Lewis, Tristan Hughes and more. Get 50% off your first 3 months with code DANSNOW. Download the app or sign up here.PLEASE VOTE NOW! for Dan Snow's History Hit in the British Podcast Awards Listener's Choice category here. Every vote counts, thank you!We'd love to hear from you! You can email the podcast at [e-mail] can take part in our listener survey here.

This is History's Heroes. People with purpose, brave ideas, and the courage to stand alone. Including a pioneering surgeon who rebuilt the shattered faces of soldiers in the First World War. You know, he would look at these men and he would say, don't worry, Sonny, you'll have as good a face as any of us when I'm done with you. Join me, Alex von Tunzelman, for History's Heroes. Subscribe to History's Heroes wherever you get your podcasts. Hi everybody, welcome to Dan Snow's History Hit. 1782, a grim year for Britain.

If you can believe it, there were three prime ministers in one year. Yes, that's how crazy things got. The American Revolutionary War has effectively ended in a defeat for Britain. Its 13 colonies have broken away. London's capital was only just recovering from the upheavals of the so-called Gordon Riots of 1780, in which more property was destroyed than would be destroyed in Paris during the French Revolution. The Gordon riots had been caused by Parliament attempting to reduce the penalties, the discrimination on British Catholics. And a rabble-rousing politician, Lord George Gordon, had mobilised Protestants to say that this could undermine Britain and might lead to Catholics entering

the army, entering politics, committing treason, and engineering a takeover of Protestant Britain. There were hundreds of deaths. Magistrates effectively lost control of London for a week. And in 1782, a very different kind of threat emerged, one that also had unpleasant foreign connotations. And that was a caterpillar outbreak. They'd had war, they'd had riot, and now here came pestilence. This is such an interesting story. It's a story about science, it's about communication, it's about celebrities making money out of health scares. It's all here, folks. John Lidwell Durnan is a lecturer in history of science at the University of Exeter, and he focuses on food and population and race in the British Empire in the late 18th century. He's written a brilliant paper on this London caterpillar

outbreak. And particularly given all of our experiences during COVID, I think there's a lot for us to think about here and learn. You're going to love it. Enjoy. John, thank you very much indeed for coming on the podcast. Thank you so much for having me. It's a real great pleasure to be here and to talk about this unique and interesting event in London. Yeah, it certainly is. Well, tell me about London in the late 18th century. It's such an exciting and fascinating city, isn't it? Is it becoming, by this point, the world's largest? Absolutely. I mean, London is becoming one of the premier wealthy metropolis centres within Europe. But that doesn't mean that it's not without its problems.

And most of what my research has been into are some of the real flashpoints and crises that strike the city. So, I mean, we can review a couple key things to kind of set the scene. I think it's important to remember that London is still learning how to read. About two-thirds of men can read somewhat. Fewer than half of women are literate. So literacy, education levels are certainly nowhere near what they would be today. There are no state schools in the city.

There are some grammar schools, of course, that are fee-paying. There are charity schools run by Missions for the Poor. But largely speaking, education is not, again, there's not a wide enfranchisement of education in the city. And it's prone to disease outbreaks. And no social housing, no state building of houses. These people arriving in the city to take advantage of this kind of economic miracle that's going on, where are they living? And how are they living? So the city is expanding from a concentration of financial and commercial interests, which are around Westminster.

They're around St. Paul's Cathedral. So this is the period when what are small villages like Hackney, Bethnal Green, these are beginning to be absorbed within to the metropolis itself. So this is the period at which the city's expanding and most people who are arriving for work in industry are ending up moving into very impromptu and often squalid conditions on the outskirts of what is then the city. Is that cause for concern by the elite? Is this seen as a kind of public order issue, or potentially a kind of crucible of revolution and disorder? Absolutely. There's a lot of debate and discussion around what this means for the future of the country and the future of the city. We have figures, kind of philanthropic

reformers like Jonas Hanway who are emerging at this period. Jonas Hanway is outraged by the sanitation conditions within the city. He's also outraged at the illiteracy. And Hanway even goes so far as to say that the British state, the government, is profiting from keeping its people in this squalid, illiterate condition. So there are even arguments that keeping the citizenry poor and illiterate are serving political ends. So there's a lot of debate. Well, and speaking of popular, I don't know if ignorance is the right word, but it was always said around the Gordon riots, the enormous disorder in 1780. Is it true,

or is this just smug commentators that people weren't exactly sure why they were rioting in the Gordon riots? Well, I think that can always be a question for riots. I mean, we should have a little context for the importance that crowds and political gathering have played in the longer history of English civic life. So crowds, even rowdy, violent crowds are nothing new in Britain. It's always been part of the political lay of the land that a political leader interested in commemorating an event or rallying support for a cause organizes a public spectacle, a crowd. These usually end up having a carnival-like air. There's celebration. They can also turn violent, of course. There's a

term that emerges, king mob, shortly after the Gordon Riots. And there's this idea that the English people, the English citizenry, have this right to organize and become what can even be a violent, misruled mob, that that's part of the political scene and flavor. Certainly, the Gordon Riots in 1780, they really changed the public sentiment around that forever. There was a reasonably old-fashioned professor when I was at Oxford a long time ago now, and he used to talk about how actually riots were part of this strange 18th century constitution where these people rioting were denied the vote in most cases. And yet they were, by rioting, you are expressing an opinion,

you are able to play a part in the political process in some way. Yeah, absolutely. Absolutely. All through the 1750s, you have the food riots, which strike a lot of market towns, rural towns in England. There's a sense that although it's chaotic and violent, mobs, even rioting, become part of a kind of almost functioning political system so that there's not universal suffrage by any means, but that rioting somehow plays a role within the political system of providing the public with the means to push back against an unpopular or unruly government. And there are certainly politicians, often on the radical end, who feel that that is maybe not the ideal system, but that it's a symptom of a healthy public populace. Yeah, the aforementioned professor said, now, would you guys rather be able to vote or just chase a senior member of the cabinet around and like throw muck at him and smash his windows up? Now, tell me about into this sort of febrile, growing, slightly unstable city. Tell me about the outbreak. What are we talking about here?

So what we're talking about is a mild winter, which leads to a lot of confusion and panic throughout the city. The main villain in this kind of natural history is a species called the brown-tailed moth. And the brown-tailed moth, it's native to Europe. It had certainly lived in Britain for ages. It is an invasive species in North America, but that's much later in the 19th century. It's simply, it's well known. It's well known to the inhabitants of England, if not necessarily everyone in the city. What happens over the winter of 1781, 1782, this is just two years after the Gordon Riots, which is an important key to this story, the moths experience a population surge. Now, we don't know to this day, we don't always have the ability to understand and predict when these insect population surges happen.

Certainly, we can point to the mild winter. Possibly some of the predator species hadn't done as good a job as normal in terms of picking them off. the citizens of London and the surrounding suburbs notice that almost everything that's green is being covered over by these kind of web tent nests. And if you Google image brown-tailed moth tent, you can kind of get an image of them. They can be quite otherworldly. It looks like a kind of bag made out of webbing, and it's filled with little inchworms that are becoming caterpillars. Before I go on, presumably these people were closer to the land, close to the seasons and the animals and the crops than we are today. Was this something they would have been familiar with? Were they worried about plagues and pests and these kind of blights? Or would this have been

deeply confusing to them? Let me put it this way. I think this is a point where expertise and information flow sometimes gets tangled up. So certainly there are people who are, just as you say, very close to the land. They recognize these tents or nests as belonging to the brown-tailed moth. They know not to touch the nests because they're toxic and can cause a bad rash to break out. So there are certainly people that see them and know what is happening. Another group of people who might recognize the threat are medical students or anyone who spent some time studying natural history. If you're training to be a doctor, part of your education is going out with an entomologist and learning to identify insect species and collect them.

So any young medical students in London, if they're good, they're going to recognize that these are nests of the brown-tailed moth, but that's not everyone. And however we want to explain it, the newspapers through March and April fill up with a lot of alarm from people writing to newspapers saying they don't know what species is developing these nests across the city and where it's come from. We should say also this is against the backdrop of the catastrophic American Revolutionary War, probably the worst reverse faced by Britain in the 18th century. So is this a population who are on edge?

Absolutely. Yeah, we don't want to leave out the unpopular and long drawn out American war. There's numerous reasons to put the population on edge. There's lots of obviously the fact that London is still being rebuilt after, you know, hundreds and hundreds of buildings are torched during the riots. So this is very much a population on edge, both politically and even existentially. So here we go. So we've got all these insects nesting. What happens? What were people worried about and what was the damage? So the actual threat isn't that great. For those who recognize the species as the brown-tailed moth, they know that this is a toxic insect. They know that it will defoliate trees, but they also know that everyone's going to survive.

It's not going to destroy local crops. It's not going to kill animals. It's certainly not going to bring the plague. But as I mentioned earlier, the economy of information is a bit different from that. And during this period, almost anyone can pay a small amount of money to take out a notice or an advertisement in a newspaper. And very shortly after the first notices around the webs appear, someone named Gustavus Caterfelto begins running these enormous ads

claiming that this insect is not only invasive, but that it has brought the plague and it is going to basically kill everyone in the city. Listen to Dan Snow's history here. I'm talking about the great caterpillar outbreak. More coming up. This is History's Heroes. People with purpose, brave ideas and the courage to stand alone.

Including a pioneering surgeon who rebuilt the shattered faces of soldiers in the First World War. You know, he would look at these men and he would say, don't worry, Sonny, you'll have as good a face as any of us when I'm done with you. Join me, Alex von Tunzelman, for History's Heroes. Subscribe to History's Heroes wherever you get your podcasts. We talk now about how the gatekeepers are no longer there and anybody, misogynist, racist, nationalist can now, and quack scientist can now reach big audiences. But it sounds like that was possible in the late 18th century too. No one was gatekeeping this guy. No, no, there were no gatekeepers, although very quickly some scientific writers, particularly entomologists, begin to try and respond to him. But there's certainly no one stopping him from taking out the ads, although the papers do feature people writing to complain

about Caterfelto's own notices. So the papers are very happy to entertain both sides. They're happy to run the advertisements. They're also happy to run the letters from people angry at Caterfelto's claims of the end of the world. We're just a tech platform, guys. We're not responsible for content. Okay, I think I've heard that one before. So tell me more about him. Did he have any scientific background?

Well, yes and no. So Gustavus Caterfelto is, I think, one of the most fascinating figures in the 18th century. He probably emigrates from Prussia to Britain in the 1770s. He knows all the tricks in the book. He's a magician. He knows card tricks. And he sets up as a traveling lecturer. He'll run a show on anything that he thinks will draw attention. So very often he's teaching you how to cheat at card games. He has a black cat whom he claims is the devil. And so you can come to a show and you can listen to the devil through the cat communicate because the cat can communicate to Caterfelto. And in

terms of his scientific credibility, Caterfelto is not the only person like this to invest a whole lot of money in state-of-the-art scientific instruments. So Caterfelto owns some of the most high-tech stuff of the era. He has an air pump. These are vacuum machines, which are very popular in these kind of exhibits. So if you go to see a Caterfelto show, you'll be able to observe the mystery of maybe a bird or a mouse or a rat being asphyxiated in the catafalto air pump. So he demonstrates vacuum science. He also has something called a solar microscope. And this is, again, a little difficult to explain, but in a darkened room, he can channel light from outside through a lens and he can project, kind of like a projector today, he can

project a larger image onto the wall. And this he uses to show people the microscopic world. So he has lantern slides of animacules and water. He's able to kind of render the invisible world visible. So it's difficult to say that he's not part of the scientific community at this moment because he has all the stuff. It's not always so straightforward to distinguish technical showmen like Caterfelto from, say, someone like the chemist Joseph Priestley, who's also touring England at this time with his chemical apparatus. Trying to distinguish culturally between someone like Joseph Priestley and Caterfelto can get tricky. As you're talking, I'm trying to work out whether we need to describe today's

YouTubers and influencers and Instagrammers and TikTokers as whether we should describe Caterfelto as kind of very modern character or whether we should just say actually today's influencers fall in this kind of historic tradition. Maybe they're not as new and innovative as we think. Well, it's certainly true that Caterfelto shares some qualities with today's influencers. Certainly in terms of contempt, many, many people regard Caterfelto as a dangerous nuisance and they publicly ridicule his followers. So to be a member of Caterfelto's audience is considered by some people as the symbol of gullibility, even stupidity. One political attacker described his opponent's political base as being basically like the

followers of Caterfelto who live in utter darkness. So there's certainly criticism at the time of the people who follow him. What was Caterfelto interested in? Selling tickets to his next show? Making money? He's certainly precarious. He needs to keep audiences coming back. And this is one reason why he continually shifts the focus of the exhibit. He is, we think, completely reliant on ticket sales, but he also sells medicines. And that might be one reason why he becomes particularly interested in the brown-tailed moth outbreak, because Caterfelto alone offers the tonic that will save you from the plague which the caterpillars have

brought with them. Wow. Okay, so he identifies this terrible threat and says, but don't worry, I can fix you. Did it work? Did the caterpillar outbreak go away of its own accord? Was sort of the scientific establishment able to gang up on him? What happens next? Well, it's not the only outbreak happening in the city at this moment. By particular misfortune, there's an influenza outbreak happening in London just at the same time as the Caterpillar outbreak. The Prime Minister of England actually dies in the influenza outbreak. So Charles Watson Wentworth dies of influenza in the summer. And there are lots of criminal raids on apothecaries and pharmacies. So we know from looking at criminal records and the justice

records that people are attacking pharmacies and apothecaries and trying to steal fever remedies. So the fear of the caterpillars and the fear of the influenza, these kind of get tangled up together. In terms of the scientific response to cataphalto, there's an entomologist living in Lambeth named William Curtis who becomes outraged by the false and dangerous notices from Cater Felto, and he decides as quickly as he can to write a pamphlet. Ah, okay. And does it spread as widely as Cater Felto's pseudoscience? I would love to be able to assess which does better on the market. Does Caterfelto sell more tickets or does William Curtis sell more pamphlets? I think for your money, Caterfelto's show was probably better value. I think if I had the choice to go back,

I'd spend my money on a seat in Caterfelto's theater. But I think this pamphlet is possibly more historically significant because it represents what I would argue to be one of the first efforts of a scientific authority to weigh in and comment on the nature of this kind of invasion. So he titles the pamphlet A Short History of the Browntail Moth. It's not really an eye grabber by any stretch. But what he does in the pamphlet is he addresses the public fears around this insect. And he also tries to predict what's going to happen. Because obviously, William Curtis wants to first explain that this is not an invasive species, it's not going to transmit the plague. But he also wants to calm fears about the possibility that, you know, this insect is

here to stay. So he needs to explain something about nature to calm and assuage people. You mentioned invasive species. Was there an element of, as there was in the Gordon Wrights, an element of fear of foreignness? Is that something people were playing on here? Absolutely. And that was by no means an unreasonable fear. The 18th century is a century of disasters in terms of invasive species. In the 1740s, Ile de France or Mauritius into this vast grain producing island, which was going to feed their navy. And when locusts arrive, almost all efforts at agriculture are rendered basically impossible. You have insect species blowing across the channel. So in the 17th century, in the 18th century, there are occasions where possibly sawflies or cockchafer beetles low from mainland Europe to Britain or Ireland and decimate agriculture.

So there's a real sense in this period that Britain's position as an island is very fragile, and there are insect species which could result in widespread famine. What's so interesting, if you compare this to previous actual plague outbreaks from the 14th to the 17th centuries, I mean, William Curtis, is his pamphlet largely correct? I mean, are we approaching a modern understanding of science here? So we're injecting real modern thinking into this kind of age-old information melee. I mean, certainly an entomologist or a public health expert who has the choice of Dr. Caterfelto's account of what these insects are and what they're doing and William Curtis will easily recognize the accuracy and the reasonableness of Curtis's position. But it would

be a mistake at the same time to say that Curtis's pamphlet is not in itself political. The brown-tailed moth is a pest. It's an agricultural pest, and it is also toxic and dangerous on contact, not in a mortal sense, but it certainly represents a threat to the public. William Curtis omits any discussion of this species as a pest. And that's very unique and very hard to explain, given that if you look at discussions of the brown-tailed moth before 1782, and again after 1782, people describe it as a real scourge. What's the legacy of this? Do you think that this cool-headed science, does this help fend off what could otherwise have turned into a great moral panic? I mean, Does this help fend off what could otherwise have turned into a great moral panic?

I mean, is this a model that establishes this sort of moral panic, health panic, scare to be met by the soothing balm of expertise? I like soothing balm of expertise. I mean, possibly, possibly. William Curtis is a member of the Linnaean Society of London. Charles Darwin is later a member of that same society. So this is an important scientific body. And very interestingly, in 1791, the Linnaean Society awards William Curtis with a commemoration and a celebration of this pamphlet. They commend him for intervening and assuaging and calming the public. So I think it's certainly recognized that this is something new within the metropolis, that this represents a new confrontation of scientific authority with what's represented as a dangerous and wrongheaded and seductive public discussion around what the insects are. So there's certainly a feeling within the scientific

community that William Curtis has done something commendable, he's done something new, and something that ought to be emulated. In terms of fighting a public association of caterpillars with plague, though, that's something I've also been very interested in. And if you look at medical texts written in the 1780s, 1790s, medical writers are still refuting the link between caterpillars and plague and fever. So at the same time as people are toasting success in the Linnaean society, there's obviously a pervasive sense within the public that there is some truth to the idea that disease and caterpillars are linked, if people need to write to refute it.

Yeah. Well, John, so what's the lesson here? What's the lesson for our time? Is it that we should all be a member of the Linnaean society and the world would be a better place? Is it about expertise? You know, you're writing this, you're studying this against the backdrop of COVID and other scares. What's your thinking? Well, I think one of the big lessons, and I hope this is something that all listeners can agree with. One of the big revelations that emerged during COVID was that the effort to turn scientific knowledge into policy hit some bumps in terms of rendering policies that would work across class boundaries. So there were policies that worked very well for a suburban family who could move their work onto a remote platform. Those

same policies and recommendations didn't always fit the lives of the precarious classes as well, for obvious reasons. You know, COVID lockdown was a very different experience for people living, as I said, in a suburb versus people who are in a more crowded city and didn't have those same means. I think what emerged during that was a realization that there's, during a crisis like that, there is a real gap between scientific authority and the class differences of a society that needs to respond to a crisis. And we tend to think of that as something, I don't know, maybe that belongs to our moment. But that's actually a problem that goes centuries back. And so one of my hopes is that in looking at these longer events back from the 18th century, we can see that this is by no means a new problem, that there are these communication gaps across class differences, and that more work really has to be done to

understand how scientific knowledge can be translated into policy that fits a diverse urban community. And I guess some sensitivity around that communication. It's enraging, and it's belittling and it's embarrassing to just be laughed at by scientists and told that you're just talking absolutely, that you've been taken in, you've been taken in by a hoax or a grifter. And I guess it's about creating a space where people are able to listen to expertise and sort of change their mind and there's no, I don't know, I guess there's no judgment. Absolutely, absolutely. And also, it was by no means the

case that William Curtis knew for certain that the brown-tailed moth wouldn't come back in greater numbers the next summer. He had to come down on a position, but he had to, I won't say guesstimate, but he had to take a stab at what he thought an optimal future might look like. And one of the things that I think the public often demands is that scientific authority provide a picture of the future. I mean, entomology is not the only science that would really struggle in all cases to provide guarantees or promises on what the future is going to look like.

So I think one thing that we might want to consider out of this as well is how that relationship between a public or societal demand for a picture of the future can be mediated by scientific authority in a way that isn't belittling or over-promising. Well, John, thank you so much for coming and talking about this. Please tell us, this came to my attention because I saw you'd written a brilliant paper. What's it called and how can people find it? This paper is open access. So if anyone wants to read it,

they can read it. It's on the Historical Journal. It is called Plague, Crisis and Scientific Authority during the London Caterpillar outbreak of 1782. Downloads are very, very welcome. Thank you so much for coming on the podcast. Thanks so much, Dan. Great to be here. This is History's Heroes. People with purpose, brave ideas, and the courage to stand alone,

including a pioneering surgeon who rebuilt the shattered faces of soldiers in the First World War. You know, he would look at these men and he would say, don't worry, Sonny, you'll have as good a face as any of us when I'm done with you. Join me, Alex von Tunzelman, for History's Heroes. Subscribe to History's Heroes wherever you get your podcasts.