In Our Time - Early Geology

Episode Date: April 12, 2012

Melvyn Bragg and his guests discuss the emergence of geology as a scientific discipline. A little over two hundred years ago a small group of friends founded the Geological Society of London. This organisation was the first devoted to furthering the discipline of geology - the study of the Earth, its history and composition. Although geology only emerged as a separate area of study in the late eighteenth century, many earlier thinkers had studied rocks, fossils and the materials from which the Earth is made. Ancient scholars in Egypt and Greece speculated about the Earth and its composition. And in the Renaissance the advent of mining brought further insight into the nature of objects found underground and how they got there. But how did such haphazard study of rocks and fossils develop into a rigorous scientific discipline?With:Stephen PumfreySenior Lecturer in the History of Science at Lancaster UniversityAndrew ScottProfessor of Applied Palaeobotany at Royal Holloway, University of LondonLeucha VeneerResearch Associate at the Centre for the History of Science, Technology and Medicine at the University of Manchester.Producer: Thomas Morris.

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get your podcasts. Thanks for downloading the In Our Time podcast. For more details about In Our Time and for our terms of use, please go to BBC.co.com.uk, forward slash Radio 4. I hope you enjoy the program. Hello, the Geological Society of London was founded at a dinner at the Freemason's Tavern in Covengarten in London

on the 13th of October 1807. The 13 founder members wrote a declaration in which they outlined their aims of, quote, making geologists acquainted with each other, of stimulating their zeal, of inducing them to adopt one nomenclature, of facilitating the communications of new facts and of ascertaining what's known in their science and what remains to be discovered. Geology, the study of the origin, history and structure of the earth

was still an emerging discipline in the early 19th century. The very word geology was new, first used less than 100 years earlier. Many earlier scholars, including Aristotle and Leonardo da Vinci, had paid attention to the mistress of the earth and the materials from which it's made, but how did the piecemeal study of rocks and fossils turn into a rigorous scientific discipline? With me

to discuss the history of geology are Stephen Pumphrey, senior lecturer in the History of Science at Lancaster University, Andrew Scott, Professor of Applied Palliobotany at Royal Holloway University of London, and Lucia Veneer, research associate at the Centre for the History of Science, Technology and Medicine at the University of Manchester.

Stephen Pumfrey, can you talk about the first scholars to turn their minds to what we now call geology? It probably goes back to ancient Egypt, where geology, the science of the earth, could well have been developed alongside geometry, the measurement of the earth, because of the annual floods on the plains of the Nile. And it would appear that that was there that the thinkers began to try to think of rational explanations rather than attributing to gods, the annual floods. We can certainly see that in the pre-Socratic Greek thinkers. Take, for example, Thales of the 6th century BC.

Whereas the pagan idea was that the god Poseidon was responsible for earthquakes, Thalys argued that the landmasses floated on water, and it was the waves of the seas that caused upsets in the earth. So there's an example of someone arriving at a more rational proto-scientific explanation. Did Aristotle, as it were, lay down the basis of water? what will be thought of as the structure of approaching this not yet named discipline for the next several centuries? Well, no, I don't think so. I think it's certainly, as you were suggesting, an anachronism to talk about geology at this time.

And I think one can certainly think of two or three reasons why thinkers from Aristotle's time really through to the 17th, 18th century, couldn't have been doing something that we call geology. The first reason is that certainly within those periods that we're going to talk about dominated by the Christian, or Islamic tradition, thinkers were limited to a age of the earth of 6,000 years created by God about 4,000 BC. And that simply doesn't allow that they didn't, as it were, have the time to think of the long-term geological processes at the centre of geology. By the same token, they had to think of changes as relatively short, unless they were

catastrophic like Noah's flood, relatively small scale. So they don't really think about the sort of huge dynamic forces which modern geologists think about. And then finally, they're limited very much to observations of the surface of the Earth. And of course, in Europe, they know very little about the whole Earth and certainly very little about deep down in the Earth. Of all of those reasons, what they're doing is something more akin to a kind of cosmogony or thinking about how one might understand the Earth rather than geology as a modern subject.

So nobody could really reach back to, say, Aristotle and Pliny and gather anything useful for the forward movement of the study of what became geology? Oh, I certainly wouldn't say that, because Aristotle in particular has a very well-eemed, developed and fruitful theory of the earth, which you could call a geological theory. He has his idea

of the four elements, Earth, Air, Fire and Water, and in a book called Demetriogica, he discusses how those four elements interact with each other. So, for example,

although, of course, the element Earth forms the great globe at the centre of the universe, air and water and fire and mix in with it, so Aristotle develops the theory that there are

huge caverns full of water which are responsible for floods and deluges. He also thinks that there are channels or passages where fire can escape causing earthquakes and volcanoes. And he also has the idea that there are two associated humours or spirits or vapours in the earth, a watery one which condenses to form metals, and a fiery one which condenses to what he called fossils, and we would call fossils in the modern sense of things that look like organic specimens,

but also other rocks and minerals as well. And there's another reason, I think, why one can't really think of geology, because until really relatively recently, fossils were considered to be things that were formed in situ. They weren't living creatures which had sedimented there. But Aristotle's theory was very fruitful in many ways for thousands of years. Lucia Bonaire, this, insofar as it was, a theory about how you study nature or an idea about how you said to match you did obtain in Western Europe for several centuries after. You began to be challenged in the Renaissance. Can you give us some idea of how that happened? Well, yes. With various scholars drawing on the works of the ancients, Aristotle,

but also others such as his pupil, Theophrastrus, and a botanist called Diochoridis, as well as Pliny the Elder, who wrote a very large, voluminous natural history, which catalogued and described plants, rocks, everything, really, that Pliny came across, medieval and very early Renaissance scholars drew on these works, began to try to correct them as they realised that plants they were encountering in northern Europe were not sort of variant forms of things that Aristotle Pliny and so on had described,

but in fact different species. And then, of course, with the exploration extending to the new world, to the Americas, new plants, new animals, new kinds of geological events to use this word that we really shouldn't be using for the period, were being observed. And gradually people began not only to try to sort of correct the ancient texts, but to criticise them, to extend on them, to describe new things, to produce new books.

Botanists and physicians in this period were particularly interested in plants because, of course, they could make medicines from them, but also more general natural histories of animals, of minerals, and so on were being written at this time. There were many active scholars. ancient books, the development of printing, therefore easier access to knowledge around the place was a factor here as well, wasn't it? Yes, yes, certainly.

Certainly with the extension of printing and therefore the birth of the book trade, perhaps you could say, for which in later in the 17th and the 18th centuries, Holland in particular became a centre. Yeah, the spread of knowledge was certainly easier. The earlier period is described by Stephen when Aristotle is saying there are channels underground and reservoirs. It's a very great effort of abstract thought to get to grips with what they could not see and observe. Remember that you have knowledge with the means at your disposal. These began to change, not least the nature of the earth, when deep mining began in Germany.

And we have a mining engineer, Georgius Agricola, is his Latinised name, who made a substantial contribution to what we still cannot call geology. I think that's the last time I'm going to say that. But can you describe what he did and how he moved things forward? Yes, Agricula was born in 1494

and he was a farmer, or the son of a farmer rather, hence his Latinised name, Agricola. But he was a good student and he went to university and then in 1527, he was appointed the town physician of a new mining town in Germany called Joachimstahl.

And there he spent pretty much the rest of his life. He worked in Chemnitz as well, but in that area of Saxony, pretty much the rest of his life, he was a prolific writer. He wrote theological, mathematical, historical treatises, but also he did a lot of work collating, collecting information on mining, on minerals, on fossils, and towards the end of his life he produced a number of books about minerals, rocks and so on. One was de natura fossilium, it's generally known as now, but he's probably most famous for De Reh Metallica,

which was published after his death and basically just means on metals, and was a treatise on mining and minerals based on the local area, but also extending more widely across Europe. And this was probably the first treaties on, on mining that was widely circulated. So we're getting an alliance between technology and scholarship, aren't we? He's going down, he's in a place where they're digging and they're finding new stuff down there and they're bringing it up

and he's saying this changes the way we look at the world. Precisely, yes. It's probably the start of this link between the philosopher who is interested in theories drawing on the practical knowledge of the artisan of the miner in this particular case. and that treaties was used as a mining text, certainly for 200 years after, and is obviously today very valuable for historians of mining.

Andrew Scott, a near contemporary of Agricola was the Swiss naturalist, Conrad Gesner. Can you tell us about his approach? Yes, well, Gessner was very interesting character too. I mean, he was born in 1516, and he was also the son of a poor farmer. But he was obviously a very intelligent man. He started off studying Latin, Greek and Hebrew

and made huge compilations of works of published in those languages. He then liked others. So they're all to do with natural history? No, it was to do with anything. I think any, you know, sort of he was one of these very scholars of who couldn't decide what he wanted to do because after that he went to study medicine

and he's traveled around Europe and went to Montpellier and other places. And then he became a professor of physics. but then he decided to study, he was so interested in sort of natural history, if you like, he took on the job of a physician in Zurich and in his spare time published loads of works to do with animals, to do with plants, but then also to do with fossils. And one of the innovations that he introduced was the fact that not just like agricula had sort of done compendiums of minerals and fossils and so on.

But he had three major innovations. Firstly, in his books he illustrated material. So here we had comprehensive illustrations of the different kinds of fossils. And in that sense, we use fossils in the terms of anything dug up. So it's not just the sort of fossils that we think of today as once living organisms, but you're talking about anything that was dug out of the ground. He then had the other ability to collect material together. So he was interested in accumulating specimens to help him in his classifications.

So for the first time he was trying to put together people's cabinets. So one of his friends, Yohan Kentman, had an arc or a cabinet of these different specimens. So he illustrated that in his book. And the third thing he did was he created a network of interested people. So that he had been around Europe and he was in correspondence with people. in Britain, in France, in other parts of Europe, and more or less said, well, send me anything you've got. And so when he published his first part of his book on fossils,

unfortunately it was, if you like, almost like an advertising booklet, saying this is what I'm going to be producing, because he had produced four huge tomes on animals in their classification. And he wanted to do that on fossils, but he just produced this prodomus, this sort of introduction. But he sent it very, very widely around Europe and almost saying, well, look, here is what I'm doing, this is my project, please send me specimens.

Very much like Darwin. Yeah, I mean, incredible really, because, for example, in Cambridge, they have 12 copies of his book because he just sent them to everybody saying, please send me material, this is my big project. Unfortunately, he was a physician at the time of plague, And just after this was published, he died of the plague. Can we just step aside for one second, Andrew Scott? We'll be talking about European scholars and we'll continue to do so.

But China could lay some claim to having got there earlier in some ways. Can you just explain that? We'll use it as a digression, but I think we should hear about it. Yeah, the Chinese is very intriguing because even in the third century, there was a guy called Changhua. Third century AD. Yeah, third century AD. and he considered all pine trees, for example,

turned to stone after 3,000 years. Now that's interesting because there he's actually believing that something once living then was turned to stone, which was something which they didn't come much later to in Europe because it was always the problem of the birth of fossils within the rock that people have believed at that kind of time. But then that way he wasn't followed up, and this is the story I suppose all the way along with many of these groups

of people. In the 12th century AD there was a guy called Lund Sun who recorded a landslide in which uncovered a fossil forest which he interpreted as being fossil bamboo. It wasn't fossil

bamboo, but anyway that's how he interpreted it and he said well actually because bamboo doesn't live in this area anymore it must be that the climate is different. So here is somebody who's making a great leap if you like. was saying, because these fossils indicate there was a bamboo here once before, but there's no longer living in this area, therefore there's a major climatic change.

So you could lay, you know, paleoclimatology and paleobotony, you could say, well, started then. But like in many of the Chinese examples in science, it kind of didn't go anywhere. Sort of, you know, they made these discoveries, but nobody followed it up. Except when we used to nickler later things, like dynamite and printings. Then it went somewhere else, which is west. Stephen Pumfrey, the Leonardo da Vinci, who is in touch with so much knowledge in the Renaissance, is again included in the list of those who took an interest in the earth, in the nature of the earth, and what it was made of. Can you discuss his, or can you tell us of his contribution?

Well, I think rather like Andrew's Chinese, he's another example of someone who has interesting ideas that don't go anywhere. He's an example of how one could think of an alternative paradigm if you were prepared to think outside the box, as it were. Da Vinci said that the fossils that look like seashells that were found high up in mountains really were fossilised seashells. And he brought his excellent observation skills to bear by showing that the fossilised seashells had kind of annual rings or annual deposits of growth, just like living seashells did.

So he made the claim that these were living things. things. And he also argued that there were tremendous forces of uplift that pushed them up to the mountains. But I think I'd want to say that Leonardo's had enough hype and because all this was left in manuscripts that he didn't particularly communicate

as far as I know weren't discovered until the late 18th century, although it's a very interesting example of thinking beyond the normal conventions of religion in terms of the age of the earth because he does think the earth is much older. He is a bit of a dead end. He may have been influenced by one or two daring medieval

of scholastics like Jean-Biridan, but we really don't know, but it does show that there was a different way of thinking possible. Religion's been mentioned, again, Ruchu, by Stephen. What influenced did religion? We're talking in the Renaissance, in Western Europe about a society, largely

not entirely believing, largely Roman Catholic, and inside the Vatican, there was an observatory, so there was science as well, but certainly a mindset that the Old Testament, Old History, of the world and people far clever

than me anyway, believed that completely for many centuries. And how did that affect particularly this study? Because, anyway, where you go? Well, yeah, it's, obviously this is a time anyway of changing

religious beliefs in Europe. Agricular, for example, who was Catholic, was very much affected by the spread of the Lutheran movement and eventually, in fact, he had to leave his hometown because of of it, because he wouldn't convert to the Lutheran view. So he was affected by it in that way.

Others were affected in the growing study of what was called chronology, which was started anyway as an attempt to put down divine actions on a kind of a timeline from the creation to the incarnation of Christ. So this was a very scholarly, very rigorous activity, but obviously it had this religious goal. But gradually it began to draw not only on Judeo-Christian records, but on the records of other cultures as well, the Egyptians, the Chinese even where possible, and so on.

And so gradually over the course of the Renaissance, this science of chronology, if we could call it, that was kind of gradually secularised and began to deal only with human history, which obviously in the earlier period had been taken to be the same as Earth history. But gradually that distinction began to be formed. So what are you saying? What you're saying is that the human history broke away from Earth history

around this time, although it was not acknowledged to be the case? Yes, gradually. Yes, exactly, as these studies spread, really. We're still talking about a time when the religious way of thinking, the religious atmosphere and umbrella, really, was inside that disciplines had to exist and had to find ways to exist inside that. Would you say, would you go along with that, Andrew Scott,

and how did the beginning of the societies, of course we've got the Royal Society here, But before that, there was the Society, a scientific society in Italy in 1603, the Academy de Lin-Chi was founded. Are they challenging this religious construct? Not initially, not at all, because if you look at the founding of that, I mean, it's an amazing situation with Federico Chazy, who was born in 1585. When he was only 18 years old, he decided he wanted to study the world around him.

So he founded the Academy of Lin-Chi with three of his mates, basically, and much to his father's disgust, decided to sort of commit himself to looking at all these different things. And so he was interested in animals, plants and also fossils and rocks around him. He persuaded a number of very important people to join his group.

In other words, Delaporteur, he got to join in 1610, but perhaps most importantly, in 1611, he persuaded Galileo to join his group. So the academy was very important. and although his father disinherited him, he actually got Pope Peter to... Sorry, Pope Paul V, made him a prince. So he had a linkage.

And also he persuaded Cardinal Barbarini to join his group, who became a very significant patron. So what's the line? What's he saying? I am going towards new knowledge and you should join in. What's he promising them? Why are they coming in with him? I don't know. I think he must have been an extremely astute guy who's just thought, you know, I want to study this stuff around me. I think it's very important.

But when you re-talking about the stuff around you know, we are talking in the area about which this programme is centred. Yes. You're talking about animals, plants, fossils. He was obviously with Galileo looking at the skies. Anything to do to try to understand the natural world, if you like. I think I've heard that Chazy, to some extent, wanted to kind of stick one to the church, as it were. He was a bit of a kind of anti-establishment figure, and he certainly, I believe, took on people like Jamberties and a reporter and then Galileo when he gets controversial, because by patronising these controversial figures,

he's able to show his independence of thinking from the standard ecclesiastical line. But he does with a frame. He takes up a big study, doesn't he? The study of Umbria, is it, when they're just collecting masses of material. He did, and it's very interesting because obviously these were in his own lands and he started collecting what we were.

we call fossil plants. It was fossil woods. And this was a very revolutionary study because it was the first time that anybody had done systematic fieldwork that is going round the lands and actually commissioning people to draw the landscape and the fossils in the landscape.

So we still have those drawings? Yes, and those drawings now are part of the Queen's collection because they were bought by George III from the Papal families. They were collected together by another member of the group Cassiano Darpocet. but what he was able to do was he collected the specimen,

saw their field localities, and tried to understand their nature. And he obviously was having a great problem. He collected, and there was over 200 drawings in this collection. The problem was he couldn't decide whether they were once living things that became stone or whether they were stone, which became rather mimicking living things.

And he never got round publishing. He actually died in 1630. But it's obviously well known around Europe because people started writing to each other saying, well, we've heard about this project. We need to know more about it. And so Staluti, obviously, were one of the founders with Chazy of the Academy, decided he would write a small little book about this. He only published about 13 of the pictures in 1637. But

in that, he did two things. Firstly, he showed that they had done field observations, that they had done experiments even, and he came to the conclusion that these weren't once living. Now, the problem they faced was that all the fossil plants they had, all the logs, weren't upright. They were just logs in sediment. So they said, well, surely if they had been once living trees, they would be upright, but they didn't find any upright trees. and then secondly they had some specimens

which were wood at one end and stone at the other so which way around was it they took some specimens back to their rooms and left them in the library for a month and found that the rock had become fossil well what actually probably happened was that they had a decaying, piratized piece of wood surrounded by sediment

and it just fell apart and so it looked as so it was changing its nature Can I briefly, Stephen, it almost reaches a sort of for geology. An interesting climax when you have many people, including the Irish bishop, predate of all island, James Asher, calculating the length of time the earth, much ridicule for it now, but not at the time, that it was about 6,000 years old. That was fairly commonly accepted, wasn't it?

And that would be a big bar to what these chaps were doing. Yes, and you're right, Usher has been ridiculed for that, and we must remember that actually Isaac Newton, the great scientist, had a very similar chronology himself. And Usher was an extraordinary scholar. He had a huge network of informants that he used his position to acquire. He used the very best biblical scholarship. And as Lucia said, he looked at all the latest scholarship on other civilizations.

And he worked out that the date of the country, creation of the Earth must be 4,000 years plus four, because he knew that Jesus was born, as it were, four years before Christ. And then he added on the 23rd of October, because he used the very latest astronomy from Johann Kepler to work out when the autumn equinox would have been that year, which was the conventional time in the Jewish calendar to assume that the Earth was started. On the basis of extremely good scholarship, and I must say, looking through his correspondence as I have, it's amazing to see such extraordinarily excellent methodological work, which we would now say is all a complete way, of time. I want to go across to a man called Nicholas Stino.

That's his Latinised name again. He was Danish, born in Copenhagen in 1638. And Lucia, can you tell us about him? And then about the two, something about him, and needn't be a full biography. Just get us going and then what he contributed. Yeah, so Stino was

Danish and again a prodigious student born in a relatively poor family. And he really got very interested in the world around him. He began medical studies. He did a lot of work in anatomy and he ended up in Tuscany in the 1660s, first doing work on anatomy and then tutoring and was given a shark's head to dissect and he noticed that the teeth were very similar to rocks or rather

fossils in rocks in the local area and he identified these as fossilized sharks teeth so as organic remains as opposed to as they were generally thought to be in the region something that had grown in the rock after it had formed so this sort of began his his natural historical studies as it were and he worked a lot on this in the 1660s eventually publishing a theory of the earth Well, I described you in the notes that you have written as important breakthroughs. The two principles. Can you describe what they are? Yes, he did a lot of work about how the different layers of rock that you can see must have been formed.

And so he discussed the principle of superposition, which is that when the layer of rock was formed, then everything that was above it must have been fluid. and it sort of sedimented out of this fluid. So you can tell the relative age of the rocks, the oldest are at the bottom and the youngest are at the top, and they were laid down in that order. And the other principle was one of horizontality,

that because this was precipitating out of a fluid, it was level. That's very important because that tells you that the earth has not been static since, because you can see that some strata are tilted or even folded right over on themselves. So that was very important. Can you develop, is there anything, Andrew Scott, can we develop the idea of Steener's contribution? Yes, I think one of the thing is we talked about his original work on sharks' teeth.

It's very interesting because those shark's teeth, the fossil ones, or tonguestones as they were known, were actually quite common and they were found in many cabinets of people at that period. It even occur in some of the drawings from the Academy de Lynchey. They were found very commonly in Malta. But the thing that Stano noticed was that many of them showed signs of decay and wear. And he argued then they couldn't have sort of grown within the rock because then there would be pristine. You know, because they showed this sort of decay and wear,

they have to have been buried in the sediment. And they also then would have been impressed in the sediment. sediment. So therefore, they must have, he didn't say exactly that they were once living, but they were likely to have been once living, from once living organisms. And I think that was very important because it's then showing you that you had at least several periods of deposition of organisms within the sediments. And so you're beginning to get the idea of geological history that could be read from the rocks. And he then had developed this idea. that in fact you have periods of sedimentation. Then he seemed to think that you had periods of erosion of material from beneath and then the collapse of rocks above to sort of form some mountains. So he was a bit confused about this, but we talked about religion. This was a shame for us because he started out as a Protestant. But during this period of time, he was actually then converted to Catholicism and gave up upon him.

on his geological studies and then became a practicing priest. And so it was tragic really that he converted because he gave up. He was developing some very interesting new approaches to understanding geology. One of his contemporaries Stephen Poppery in

this country is the English scientist Robert Hooke. And the Royal Society had been formed in 1660 as you know, so we're talking about a contemporaneity here. Are they, are some of those men onto this? They are. And Robert Hook, in particular, he seems to have been especially interested in the nature of the earth. He had a very strong theory that there were internal fires in the earth, which caused earthquakes and that earthquakes were responsible for really quite large, even catastrophic changes in the earth surface. Indeed, Hook seems to be bringing together some of the themes that are emerging in this programme. He had acute powers of observation. He was, of course, famous for his use of the microscope. And he argued for,

for example, that petrified wood really was wood, because under the microscope he could see the same cellular structure that he's recorded of living wood in his micrographia. So he asserts that fossils that look like living things really were once living things, which is still quite controversial at the time. He asserts that there are powerful subterranean forces which have produced these changes and lifted fossils up onto high ground. and he also asserts a very long age of the earth. He certainly believes it's much longer

than the thousands of years that someone like Usher would allow. And we find him in one of his lectures in the discourse is an earthquake actually quoting a Chinese figure of he says, I don't know whether it's true, 88 million years that one Chinese scholar had apparently said. I mean, without being silly about it,

it's a heck of a leap to say that from 6,000 to those millions. It is. It is. And... He said it in public. He said it in public. public and indeed his friend John even recorded that I think he says

something like, and many gentlemen were much vexed by his lectures. He does seem to have had some supporters in the Royal Society who were prepared to consider a longer time scale. So the paradigms beginning to break down with the emergence of new science. It's certainly not true that they're discarding religion

but they're looking for a new synthesis between science and religion. The interesting question, some historians have said, well, Hook really does represent the beginning of modern geology. They're all the elements in place of Hutton, but I don't think that's quite true. But Hook was not celebrated, and the reason, as always in Hook's career, is Isaac Newton, who hated him. And Isaac Newton, when Hook died and took over the President of the Royal Society,

made sure that he championed John Woodward, Hook's big, conservative enemy in these theories of the earth. Lucha, Lusia, Lee, towards the end of that century, the 17th century, the thing is being moved forward quite rather more quickly than it did in the past, and there are two factions, the Neptunists and the volcanists. Can you tell us about their dispute and why that originates? Yes, so the Neptunists were sort of following Steno, really, in a way, and not only Steno. His work had been very influential, cut off as it was,

by his conversion to Catholicism. But he had posited that the earth had begun somehow as completely covered with water, and all the rocks had sedimented, precipitated, out of this and then he'd had some processes of erosion and collapse and flooding and so on. So the Neptunist idea is really this idea of the initial primeval ocean surrounding everything, covering everything, so that all rocks are what we would call sedimentary. And of course, Neptunists because of the Roman god of the sea Neptune.

That's why they're called that. The volcanists, on the other hand, Roman god of fire, say that no, clearly not all rocks have their origin in water-based processes. Look at basalt, for example. That is clearly solidified molten rock. So basalt is really sort of where the argument begins, as it were, in the late 17th and early 18th centuries. And in the 18th century, then people are studying things more closely,

looking particularly at volcanoes, for example, and realizing that there are perhaps other rocks as well that have a molten origin, a volcanic origin, rather than a sedimentary or oceanic origin. So the debate goes on. It's really a question of where exactly in it people decide to stand in a way because nobody really denies that probably most rocks are sedimentary. On the other hand, only very few people actually hold the extreme view

that all rocks have an origin in water. The volcanists win basalt, as it were. So certainly by the late 18th century, most people are on the nectunist end of the scale, but certainly admitting that some rocks have the origin in volcanoes. Andrew Scott, this brings us to James Hutton, a natural philosopher, a farmer under scientist in Scotland, who became involved with the Scottish Enlightenment

and has been called the father of modern geology. Can you tell us something of his work? Yes, I mean, Hatton was a very important character because we forget they had lots of different friends, in Edinburgh. He was a very intelligent man. He was friends with Adam Smith and with a number of others. He was actually there when Robert

Burns met Walter Scott. So he had a lot of people who he was working with and knew. But he initially studied medicine and did a number of other chemistry he got particularly interested in.

Went round Europe and studied things, but he inherited a farm in Berwickshire. And as in many things that Hutton did, he got really involved in this and wanted to sort of try to understand the nature of the different soils in which he was farming. And he was actually looking

at, across his farm of very different rock types. So he wanted to understand about that and he went training down in Norfolk to try and understand agricultural practices. He got involved in chemistry and he actually developed with one of his friends a chemical

industry for Salamoniac from the city's so he actually began to get a certain amount of income, which allowed him to then pursue his real interest that's become geology. He was very interested in the different rocks around Scotland and around England and so on. And he began to realize that it isn't just a matter of there were sedimentary rocks, which he could see, but also he was able to demonstrate that maybe some of these sedimentary rocks have been hardened, and therefore it required heat from beneath.

from the earth itself. And then he also noticed that some things like granites, little fingers of granites, went into sediment. So therefore they must have been molten and then intruded into the sediment. So he began to

realize that all of these different things happening with lots of different layers. He noticed that some rocks were at angles, some were horizontal. So there must have been some kind of mountain building episodes. And so he began to develop the idea of an endless cycle of deposition of rock, of hardening of rock, of uplift, of mountain

building and then re-erosion. And so altogether, he really began to put together a number of these different themes, if you like, to show that many rocks were perhaps once molten, some were sedimentary, and that they all together, there was a very long history must have taken place for these rocks to become in their different angles in different ways in which they were seen as we see them at the earth's surface today.

Geological time, if you like, was something which he really demonstrated had to have been significantly long. And his work was read by the Frenchman Jean-André de Lucille and he who invented the word geology. Is he significant in other ways to look? Did he take forward Hutton's notions?

Well, no, he didn't take Hutton's notions forward. He criticised them very strongly. He disagreed completely with Hutton. And he was a very interesting figure in that he certainly made no bones, as by this time a lot of people actually did, about declaring his religious position in this. He didn't have no interest in adhering to a biblical time scale, but he did want to uphold the truth, though not necessarily the literal truth,

of the Bible. So his main concern, in fact, was to date the deluge and see if traces of it could be found geologically, or possibly they couldn't be. That was part of his question. But he looked very closely at strata, fossils, and at geological phenomena like the increase in the delta of the Rhine. And that was a measurable phenomenon that he could see in his own lifetime, changing. Is he like Bufant before him, the earlier French geologists, interpreting the seven days of creation as seven long ages? Yes, yes. He has that very similar idea there. Stephen Pompeii, are we getting to the station now where geology,

we've got the, at last we've arrived at the name of the discipline. Is it emerging as a discipline separate from other scientific inquiries? Yes, I think it is. I mean, I'm going to see to my experts in this field, this, but I think as we've heard from Andrew, we've got many of the conceptual elements of geology in place in terms of the sequence of events, the long time scale, the powerful Neptunist and volcanist forces. We've got still a broadly religious framework, but an escape from that constricting time scale. We're now into some geological deep time.

And perhaps more importantly, like many other disciplines at this time, we're moving away from a generalized natural philosophy in the late 18th century into a series of scientific disciplines. Geology is professionalising, but so is chemistry, so is astronomy and so forth. They're founding their own societies. There are beginning to be professional positions, particularly for people working in the industrial and practical applications.

So that's all I can say. But yes, I do think we're now arriving at a period of geology as a professional subject in science. And Andrew, we get to the Sergio, we've got the formation of the geological society and then the arrival of Charles Lyle with his book in the 1830s and the thing is really underway then.

Can you give us, can you sort of sum that up for us? Yes, I think the Geological Society was so important in, if you like, focusing people's minds and a whole range of geological enterprises. And if you look in the first publications, it involves everything, not just from geology of British Isles, but also all around the world.

And people then beginning to focus on... Which dates are these? These are the early 19th century. Yeah, yeah. even in 1812, were at their first publications, 1811, 1812. And it really began to focus the minds

in developing the idea of geology as a real science worthy of great interest. And Lyle was very important because he was able to popularise geology. He developed in his principles of geology, first published verse volume of 1830, a way of people trying to understand how the earth worked

in a more popular way than, say, Hutton could have done. And it was so important that Darwin took Volume 1 with him on the Beagle. And, of course, as they say, the rest is history. Well, thank you all very much. Thank you very much, a Re souvenir, Stephen Pumfrey and Andrew Scott. And thanks for listening. Next week, we'll be talking about neoplatonism. Thank you for listening to this Radio 4 podcast.

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