In Our Time - Astronomy and Empire

Episode Date: May 4, 2006

Melvyn Bragg and guests discuss the relationship between astronomy and the British Empire. The 18th century explorer and astronomer James Cook wrote: 'Ambition leads me not only farther than any other man has been before me, but as far as I think it possible for man to go'. Cook's ambition took him to the far reaches of the Pacific and led to astronomical observations which measured the distance of Venus to the Sun with unprecedented accuracy. Cook's ambition was not just personal and astronomical. It represented the colonial ambition of the British Empire which was linked inextricably with science and trade. The discoveries about the Transit of Venus, made on Cook's voyage to Tahiti, marked the beginning of a period of expansion by the British which relied on maritime navigation based on astronomical knowledge. With Simon Schaffer, Professor in History and Philosophy of Science at the University of Cambridge; Kristen Lippincott, former Director of the Royal Observatory, Greenwich; Allan Chapman, Historian of Science at the History Faculty at Oxford University.

This BBC podcast is supported by ads outside the UK. 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 programme. Hello. The 18th century explorer and astronomer James Cook wrote, Ambition leads me not only farther than any other man has been before me, but as far I think as it is possible for man to go.

End quote. Cook's ambition took him to the far. reaches of the Pacific, led to astronomical observations which measured the distance of Venus to the Sun with unprecedented accuracy. Cook's ambition wasn't just personal and astronomical, it represented the ambitions of the British Empire, which were linked inextricably with science and trade. The great transit of Venus measurement on Cook's voyage to Tahiti marked the beginning of a period of expansion by the British, which relied on maritime navigation based on astronomical knowledge. How had ancient trade routes set a precedent for colonial expansion?

What was the link between astronomy and surveying? What tools did the 18th and 19th century astronomers have at their disposal? And how did the British use science to justify imperial ambitions? With me to discuss astronomy and empire, Simon Schaffer, Professor in the History of Philosophy of Science at the University of Cambridge, Kristen Lippetcott, former director of the Royal Observatory Greenwich, and Alan Chapman, historian of science at the History Faculty at Oxford University. So, I mean, Chaffa, we tend to think of the great scientific travelers of the 18th and 90th centuries as naturalists, preeminently Darwin.

Should we also think of others as scientific imperialists? I think it's very important to understand the way in which travel and global reach and mapping and surveying were absolutely fundamental enterprises for the emergence of modern science. It's not just, though it was very important, that issues like economic botany and the environment, accumulation of natural resources were crucial for the empire. Think of tea or rubber or coffee. But it was also the case that the way in which the empire was able to exert its global control relied on what we might call its knowledge of the territory. Knowing the territory meant precisely knowing where you were. And to that enterprise, astronomy and surveying played an absolutely crucial part. In what you write, you seem to me to establish a sort of loop really, a scientific

exploration needed astronomy and safe passage. Safe passage meant empire. Empire meant astronomy and scientific exploration could proceed safely. Yes, I think it was a very virtuous circle, at least from the point of view of the scientists and occasionally the civil servants who were paying their wages. Astronomy could offer, at least potentially, and certainly from the 1700s onwards, unprecedented accuracy in determining position on the earth. It's very important to remember, too, that almost all trade routes, effective trade routes, were wet. It was much more efficient, much cheaper, much more reliable to travel by sea than by land, so that, for example, the great European ports were more closely linked with each other very often than they were with their

terrestrial hinterlands. And the way in which the British Empire, notoriously became a maritime empire, put astronomy right at the heart of the imperial project. The foundation of the Royal Observatory in Greenwich is inconceivable without the focus of the British. British state on the problem of longitude, of celestial positioning and so on. We can use longitude as an example to gather round the proposition that you're putting in rather abstract and general terms. Can you go for that? So I think it's well known that longitude poses an enormous problem for navigators, that while it's relatively straightforward to determine how far north or south you are from

the equator or the pole, it's extraordinarily difficult to determine how far east or west you are. because in order to know where you are east or west, you need to know precisely the time it is from whence you started. There were roughly two viable methods, so it seemed from the late 17th century onwards, of determining your longitude. One was the, as it seemed, fantastical or utopian idea that perhaps someone somewhere would be able to build a clock,

so reliable that you could get on a ship with this clock and it would never lose time and it would tell you what the time was where you started. If you then made a local astronomical observation, you could determine the difference between the time where you started and the time where you were, and that would tell you how far east or west you were. An alternative which seemed much more plausible but technically at least as difficult was to make a book, an almanac, which would tell you, for example, that at Greenwich, when the moon is near a certain star, it's such a time. If you made such an observation where you were, and you knew what the time was locally, you could then compare these two times together. So a clock method or a lunar method, both extraordinarily difficult. And at the start of the 18th century, they must have seemed visionary, almost infeasible.

But briefly, we have, then we got the Harrison clock and Newton swore by the Greenwich Omanagh method. Both were very important. Briefly, how does that support your thesis about astronomy and empire? Well, the speed and reliability with which long-range voyages take place is absolutely crucial for imperial and commercial control, especially in an epoch when going on a long sea voyage, as Dr. Johnson said, was exactly like being in a jail with the added risk of being drowned so that the reliability and precision of celestial navigation at sea was fundamental for the trade routes and indeed the military routes on which imperial control relied.

Kristen Lippengot, what do we know of the ancient? Can you give us some idea of ancient astronomical knowledge and the first observatories? Well, I mean, just going back to what Simon was saying about travel being wet, most travel in the ancient world was dry unless you were going along the coast. You were very rarely out of sight of land. So the great superhighways were the land trade

routes. We know, for example, the silk route or the coastal routes going all the way really from England down to Africa. The earliest observatories, though, that's a completely different kettle of fish. The earliest observatories were the homes of the priests. Because in those days, one would call it astrology now, but essentially there was a belief system that the stars were there to guide the king, whether he was an Egyptian king or a Mesopotamian king or a Chinese king. So all the people

who were watching the stars were the priests who wanted to see if the fabric of heaven was giving messages. And how did that lay a basis for astronomy? Was there something there that the people who came up in the 17th and 18th centuries could build on? It's a long, long trail. But essentially what happens is as you become more and more proficient at doing things like calendar reckoning, like mathematical astronomy, then these are the blocks that other cultures we use. And what we find is as astronomical knowledge essentially goes from Mesopotamia

outwards all across the world, each culture, uses those building blocks. So if you dig hard enough underneath Indian astronomy, you'll find Babylonian astronomy, Chinese astronomy. So it was going that way along the trade routes, but the difference is it was underneath the culture rather than on top. Several times on this program in the last few years, we've brought into play the impact of, let's say, Islam,

in the pre-European Middle Ages, and the effect they held on transferring Greek learning and so forth. Have we got a similar impact and development here in this area? Exactly. Through Persia and through India astronomy comes into Islam, and it's really between about the 9th and the 15th century that you had this huge renaissance of learning, taking the original Greek texts but building on them

so that you have incredible theoretical mathematics and astronomical work there, but for a different purpose, and never in this instance for travel. So what was the purpose there? It's primarily something, again, that one hates to use this word because it's not pertinent, but it has to do with the belief that the stars are trying to tell us something, that if you understand God's message that he's leaving for you in the stars,

you can live your life in a better way. Alan Chapman, what effect, let's move on, we've mentioned the 15th century, so I'm legitimized to move on to the discovery of America. What impact did that have on scientific discovery? But America? I think the discovery of the Americas was absolutely fundamental, not only to science, as we know it today, but to the whole definition of post-15th century Western civilization.

I mean, one of the key things about it is, first of all, nobody had any idea it was there before. If, for instance, you look at Ptolemy, or you look at Strabo, or the ancient geographers, there's not the slightest hint that there's a vast slab of land going from virtually pole to pole, about 3,000 miles west from Spain. Now, this tells the West a crucial thing.

In other words, we are not as stupid as we thought. If we can discover this vast slab of land, which the ancients had absolutely no knowledge of whatsoever, then what else can we discover? So in other words, there's the sheer power of new discovery. I think also that goes to another way as well. Most intellectual systems in the Christian and also in the Islamic world up to this time were essentially of a philosophical character.

You basically know the terrain. You know where the land lies, astronomical and geographically, and you're refining and you're perfecting. But what you suddenly find here, you don't discover America by philosophizing in your study or by deducing its existence from an ancient cartographer. You have a pack of Italian and Spanish sailors who get in a ship and hit the continent.

And this is of a very, very different level. It shows that you can have profound fundamental discovery made physically, not intellectually, although that discovery has the most profound intellectual repercussions. And it also tends to mean, too, that instead of it being within what you might call an arcana of either Greek knowledge or philosophical knowledge, anybody can test it for themselves.

You can get into ship, let's say, Drake can get in a ship from England and go and see it for himself, Magellan can do it, anybody can do it. And of course, as Simon was saying too, you used geometry to determine, in key positions such as, let's say, where Florida is, or Jamaica, or Brazil, or something like that. And then, of course, you discover a vast ocean that lies beyond America, and you can go all the way round. Now, what this tends to do is to bring what I call it instrumentalism into

science in a new aggressive way. Now, it's true scientists that always used instruments, especially astronomers, the astrolabe, of course, in the Middle Ages, is the obvious tool. But all of these instruments were regulatory. They more or less monitored what you knew already, hopefully a little bit more accurately. What you've now got with the ship, and I think of the ship as perhaps one of the first ever great instruments of pure discovery, you can find things

that nobody ever found before with it. And it's not for nothing that Bacon, for instance, in the New Atlantis in 1627, and Robert Hook, in the preface to micrographia in 1665, both use powerful maritime analogies and are constantly mentioning Drake, Columbus, Magellan,

and how, in, let's say, the 16th, The air pump, the microscope, the telescope, the hydrostatic balance, all of these instruments are, as it were, new ships, because they're taking you to places you could never have imagined before them. And what's moreover, they're also public knowledge. It's not Arcana. And so, therefore, something discovered, let's say, by a Frenchman, will be checked by an Italian or a Scotsman. And the ship, I think, and the discovery of the Americas becomes a sort of model for a much more aggressive approach to nature. So this idea which you've expressed extremely eloquently irradiates among a great number of practical persons and practical persons come into an argument

which hitherto has been dominated by theoretical persons or by small elites, priestly elites, scholarly elites and so on and so forth. So I can see it that way. But can you just give us a little more on the development of instruments? So it brings us up to the end of the 17th. What instruments were being developed? I know Hooke's idea we must extend our senses and so on. Oaks, not idea.

Can you just give us some of the instruments? so we're about to be employed as we move towards the sailing to the 18th century in about two minutes time. I think the first of these to be an absolute smasher was Galileo's first use of the telescope. And let's not forget, not just Galileo, Thomas Harry to England, was making lunar observations just before Galileo, but the telescope. The realization that a piece of tube with two lenses in it would show things on the surface of the moon, the moons of Jupiter, that there were dozens of stars in the Pliades, that the Milky Way just broke down into he meant starfish,

and that all the planets were actually spheres. They weren't just lights. Bearing in mind, of course, ancient astronomers thought each star was essentially a light, Galileo shows them to be worlds, opening up the possibility of perhaps life on other worlds. Then once you have that colossal extendance of vision, then, of course, the microscope does the same thing for a smaller world.

So you come to actually ask the question, what actually is big and small? If what I can see through the telescope is there, Yet with 100 magnification through my microscope, I can see something incredible there as well. Then you have the air pump, the realization that you can have a thing the ancient said could not exist, namely a mechanically produced vacuum. Then it has characteristics. Flames won't burn in it, gunpowder will burn in it, cats die in it.

There's the famous little horrendous poem where the Danish ambassador was shown a cat in an air pump and which went that to the Danish agent late was shown that where no air is there's no breath at last this secret did make known wherein a cat was put to death I think that's quite enough of that I know I mean we get enough letters as it is

instrumentation just proliferated and the crucial thing with it of course it was totally international now we're entering in the 18th century at 19th century at a time of extraordinary explorations and expeditions but there's a precursor about Christian Lippincott which you're particularly fond of is the wrong word interested in.

It's in 1595 an exploratory voyage by Plansius. And why do you find that so significant? Well, one of the things that we living in the Northern Hemisphere often forget is that until people start to circumnavigate, they had no reason to go south, but more importantly, they didn't know what the stars of the Southern Hemisphere looked like. So, for example, if you're doing latitude sailing, which is what they mostly did,

which is you find the latitude of the North Pole or the sun, and that's your line of latitude and you sail along it. As soon as you hit the Southern Hemisphere, you have no reference point. So, of course, as soon as somebody like Drake went into the Southern Hemisphere, he was lost not only East West, but North-South, and this is very scary. So what Plansius did, who essentially was the chief navigator and mapmaker for the Dutch East India Company,

was he hired a ship and sent three astronomers down to the Southern Hemisphere, hemisphere, and they measured 128 bright stars, each of which could be used for navigation. The main reason he did this sounds a bit jaded, but was financial gain, because

having sent those astronomers out, he had the copyright, and within three years, he had done his globes with Hondius, and had done all of his atlases. So if you wanted to sail south and come back home, you had to use his map. And in

Indeed, he had this whole trade monopolized until Blow sent another ship out a couple of years later to map different stars, not the 128, but new stars so that he could do his own globe. So we have commas, empire, there's nothing wrong with it drove the alphabet. It drove numerology. I mean, it's been, it's a very, we've astuted for all sorts of ridiculous reasons over the last 200 years, which is another series of programs. But that was part of it there. What interests me is how valuable maps work Because I didn't know It's trivial pursuit

But it's still fascinating The when pirates nobled a ship The first thing they went for wasn't the goal But was for the maps Well you can tell you don't read a lot of swashbuckling novels Sort of like Patrick O'Brien and things like that Because I always immediately go down into the hold And say, let me have your chronometer

And let me have your maps Because this knowledge was Just sounds as good as let me have your goal Hands up, can I have your chronometer? But I think This is one of the things why before Plansius were maps so bad, because maps were secret. And you would actually put errors in your maps to mislead other people. Simon Schaffer, in 1735, the first government-funded expedition went to Lapland and Peru.

Can you tell us about this and what it portended? I think this was a fundamental moment in the 1730s, because on the one hand, it showed that the state was now going to invest, really considerable resources and the most extraordinary long-range projects. And on the other hand, this was a really dramatic demonstration that rather fragile and exquisite instruments made mainly in London would survive in the Arctic and in the Andes. The point of these expeditions was to discriminate between two different models of what the globe is like. When I say state, can you tell us what that meant at the time?

Yes, that's a very interesting. point. The state in this case is the largest and most powerful of the European governments, the French, and their ambitions linked together in a way that will become increasingly characteristic, military, commercial and scientific aims. The point of the expedition, as the French understood it, was to see if it was possible to discriminate between two really rather different models of what the globe is like, what shape the globe is. The geographers employed by the French king, who'd been employed by Louis XIV, in the late 17th century, running a survey of the kingdom of France from the Paris Observatory, had concluded that the earth, roughly speaking, is shaped like a

melon. That's to say, the distance between the poles is longer than the distance across the equator. Newton and other leading mathematical astronomers concluded exactly the opposite, that the earth is rather like a pumpkin flattened at the poles. Sounds like Esop's fable. It's a bit like a fable. Yes, I'm trying to think of accessible vegetarian analogies. Could this be the basis of the difference between England and France? The pumpkin and the nuth.

Anyway, never mind. I'm being frivolous. Pumpkins versus melons. You would be able to tell which of those stories were right. If you measured the length of a degree as near the pole as you could get, and that meant that land, and as near the equator as you could get, and that meant Ecuador. So the French, in collaboration with their political allies, the Swedes in the north and the Spanish who ruled Peru,

sent the most extraordinary expeditions to the far north and to the equator. The expedition to Peru, to Ecuador, was away for a decade. Some of its members died there or stayed in South America, got married, had children, fought duels, were killed by jealous wives and so forth. But what was dramatic was that it showed that Newton was right and the French geographers wrong, that we live on something rather more like a pumpkin than a melon, you'll be relieved to hear. And the evidence for this was a series of the most astonishingly precise astronomical and surveying measurements, taking English clocks and pendulums and telescopes to the

the far north and to the equator. Two consequences flowed from this. One was the beginning of an attempt precisely to remap all the state surveys in the name of new kinds of hardware and new kinds of technique. But even more, influentially, I think, was the demonstration of feasibility, that it was possible to take very fragile measuring devices halfway around the world that, with sufficient local ingenuity they would still work, that the numbers they generated could then be trusted and brought back to the European centre, juxtaposed, analysed and new models of the cosmos developed from those measurements. Alan Chapman, a great issue for astronomers was measuring the distance of Venus to the Earth.

Why was this such a big issue and how did they set about trying to improve their measurements in 1761 with expeditions then? Well, in fact, in some ways, this takes up slightly from a point which Simon just mentioned, which I may just sort of chip in. When, of course, obviously the French were making their great surveys in the 1730s, what had really set the whole ball rolling about the melon or the lemon shape of the earth had been Jean-Richier's expedition to Brazil in 1672 to actually measure the parallax of Mars with the intention of measuring the distance of the sun.

And he found that with a new, immensely accurate clock supplied to him by the Paris Academy, that in fact it was not keeping right time in Brazil and when it was brought back to France it was keeping right time again. Now this kept a tremendous kerfuffle amongst the philosophers of Europe because did it mean that Brazil was further away from the Earth's centre than Paris was

and hence of course the suggestion that being the fatter across the poles than across the equator. But of course that expedition started as an attempt to measure the distance of the sun because we see in the wake of Kepler's laws in the very beginning of the 17th century and then especially substantiated by Newton's Principia,

if you could actually measure the distance of the sun or measure the distance of Venus, then you could, by the mathematical logic of the solar system, determine the distance of everything else in it. And it was already realized by Kepler's laws that if you could measure the distance of Venus, you could then use Venus as a sort of jumping off point by proportion to the distance of the sun.

But the problem is, if you actually have a necessary marker point on Venus's surface, you actually need this marker point to do the measure. Now, the best way of doing that was actually by using Venus as an intermediary, which had been first sewn to transit the Sun by Jurymiah Horrocks in 1639, but it was a very, very rare event. And another would not take place until 1761. Now, the idea being, if you could have global expeditions scattered as far across the Earth's surface as possible,

let's say Canada to South America, to Ben-Kulan in India, all across Europe, and so on. and astronomers could make measures of exactly where Venus was on the sun's surface on the particular day in question 6th of June 1761. When they all came back to Europe and the two French and Paris and London academies swapped their results, then you would find a key series of discrepancies. And from those key discrepancies, you'd be able to determine the parallax, in other words the slight off-centredness of Venus. But because England and France were at war then, which brings us back to the imperial idea, proposed by assignment at the very beginning of the programme, near the beginning of the programme, the information that came back was not sufficiently accurate to do the job thoroughly.

But yet, not much later, in 1769, when there was another opportunity to do this, that is when Captain Cook went on his first voyage of discovery, and others, he went to Tahiti to gather data which then proved to be very accurate indeed. Can you tell us about the Cook expedition and what that fed into the information available? Well, when Cook went down to essentially Tahiti, it's interesting because it does feed back into what we were talking about. There were two reasons for him going. The cover story, one might

say, was to go measure the transit of Venus. And one of the things that they discovered, which they weren't happy about, was something called the black drop effect, which is they thought, well, if I just measure the transit of Venus from the edge of the sun to the edge of the sun, no problem. But what happens is as Venus gets towards the edge of the sun, it looks as though Venus elongates. And you can figure out how this works. If you hold two fingers up to a light bulb and take your fingers apart and put them back together again,

you'll see they look as though they fuse. And this is what was happening. So even with the most accurate measurements, successful measurements, there was still this problem that they couldn't measure it properly. But the real reason, I think, for Cook going down to Tahiti, was allegedly he had an envelope that once he measured, the transit of Venus. He was allowed to open that says, okay, what we really want you down there for is to find out if there is a terra incognita. Because it had always been supposed, just because

God works in a very measured way, if there was a lot of Earth on the top of the globe, there must be a lot of Earth on the bottom of the globe. And so he was looking for uncharted lands and sailed south as far as 40 degrees south latitude and then headed west, hit New Zealand, hit Australia, and the rest is history. Simon. I think there's another aspect which we might want to emphasize about Cook's project into the South Sea,

which is that for the first time, Europeans encountered navigators who were at least as good as they were. That's to say the Polynesians. So that on Cook's boat, after he leaves Tahiti, is a master navigator, Tupaya,

who helped make maps of the South Seas. So while Cook, as it were, runs into lands of which he was unaware, Polynesian navigators were by no means unaware of the existence of what they called Altaireoa, what we now call New Zealand. And I think there is a very interesting effect on European perceptions of what as astronomical navigation can be, since they guessed first that the Polynesians must be navigating by the stars across the thousands of miles of the empty Pacific.

And also an emerging sense that sophisticated navigation techniques, superior forms of astronomy, might eventually be the way in which, as it were, the legitimacy of European expansion could be established. Not so much we have the Gatling Gun and you do not, but we have the chronometer and you do not. And this was taken to China, wasn't it, Kristen Liping God, a delegation, the McCartney,

delegation tries to take European British knowledge to China and say, look, we want to barter this for you because your tea costs too much. And it's one of the great failures, one of the many great failures of history. But it goes back to what we were saying at the beginning of the program is astronomical

knowledge as it traveled in the very, very, quote unquote, dawn of civilization. People took what they wanted, but left the rest. And so what the Chinese had done was they'd taken the math, mathematical basis of astronomy, but not the belief system. Essentially, the Chinese system was that the emperor was the center of heaven. Therefore, the heavens were extensions of his personality.

So then in come a bunch of English people saying, look, we've got all these wonderful instruments. They brought a planetarium. They brought a celestial globe, terrestrial globe. They bought a Herschelian telescope. They brought chronometers. We can measure your heaven. heavens better than you can. Now, there was an awful lot of politics underlying this,

but essentially the Chinese said, we don't need your toys. We have an emperor. We understand how the heavens work. So that's one of these cases, and when the whole thing with the English, with their self-confidence, got it completely wrong.

Can we move on quickly from that? Actually, the Chinese got it wrong, really, in the longer run, didn't they? Because they were quite soon overtaking. But, Alan Chapman, can you tell us a bit, Moving into the 90th century with Alexander Humboldt. Why was he so influential? I'm not. Well, Humboldt is a remarkable figure because, of course, he was, well, not only was he a centenarian,

but also, of course, a figure who travelled very, very extensively around the world. And of course, he made major surveys in Brazil, in the Central American rainforest, and of course made a great circumnavigatory journey. And what about his contribution to astronomical knowledge, Simon? I think what's really important about Humboldt's achievements is that he, showed beyond any doubt what precision measurement could do for a new science of this planet and for the universe. In his expeditions to South America between 1799 and 1806, which were massively publicised on his return to Europe and especially in Britain, what he'd done was to take a vast

armamentarium of instruments, telescopes, sextants, quadrants, barometers and so on. And he showed that the methods that up till then had been used for the heavens could also be used. used for the earth. You could, for example, more precisely measure the heights of mountains, using barometers. You could, in a sense, and I think this is really the payoff of the Humboldian project, you could begin to set up what he calls physical observatories. That's to say institutions equipped with astronomical instruments, but devoted now not just to studying the stars, but also the physical variables which govern life on Earth. Alan, can you tell us a bit more about the observatory system, let's call it the system

that grew up in the 19th century. They were planted all over there, mushroom all over the world these observations. They did indeed. In fact, I suppose the first great European observatory was Tico Brahe's in Denmark in the late 16th century. But the idea of having a centre where you would monitor heavens with very, very great precision really exploded in the 19th century.

Partly, of course, because as European culture went around the world and of course showed that Western science actually worked, then it became immensely useful. Now, of course, you have the establishment of an English observatory in Madras in about 1840, you have the Paramarator Observatory founded in Australia, and perhaps the most important of all was the Cape of Good Hope Observatory, which goes back to 1828,

which actually had a state-appointed English director who carried with him the title of Astronomer Royal at the Cape, and Sir Thomas MacLear was the most distinguished of these. But quite honestly, though, in the 19th century, the most adventurous observatories were not actually the state or publicly owned ones. It was the amateur tradition. Because in the 19th century, England was unique insofar that, let's say, like France or Germany or Russia or Austria, where you had a relatively autocratic, centralized state paying for all the goodies in science. In this country, in the

post-Napolionic period, with the obsession with personal freedom, governments kept completely off a lot of state patronage, and in consequence left more money in the taxpayers' hands. And as the Industrial Revolution burgeoned to immense wealth, The science of astronomy became the passion of many gentlemen. And so you have people like William Lassel, who found the world's largest steerable telescope in Liverpool in 1845. William Parsons, third Earl of Ross, with his whopper, giant telescope in Central Ireland.

And the founding of the Royal Astronomical Society in 1820 comes entirely out of this private tradition. So, can you link that back to the empire there, which seems to have sort of gone under the table for the last 20 minutes? Well, I mean, as Alan just said, some of the most important new observatories founded by the British state, and often through the Admiralty, are at the colonial headquarters in New South Wales, in Toronto, at the Cape, and above all, I think, in India. The new observatory founded in Madras has a pillar in front of it, which wishes everybody to remember that astronomical learning and Western civilization were brought here first, as it's.

said by the British. The significance of the Madras Observatory is directly linked to that of the Imperial Project, because it was from the Madras Observatory right at the start of the 19th century that the single largest survey of any country conducted by a state was launched. That's to say, the great trigonometrical survey of India, formerly institutionalized in 1818 and lasting well into the 20th century, a survey that precisely measured the length of an arc all the way from the very southern point of India, Cape Comorin, to the Himalayas. Its leaders included George Everest, who I understand is now to be pronounced George Everest, after whom the world's highest peak is named.

But above all, I think it... I call it Everest, I call it Eversed. Eversed, it doesn't sound quite as compelling. Let's get rid of it on this programme now. We'll punish Everest and return to Everest. But the political imperial consequences and motivations of that survey are all too clear to govern a country as to know the land, to make maps for taxation and extractive purposes. And what I think is fascinating about those large-scale surveys in Canada, in India, in Southern Africa and so on.

And in America. And indeed, of course, in America. Is two aspects. One is they're designed to use astronomical measurements to resolve potentially violent disputes. And on the other hand, what we see is the way. way projects turn into institutions. The survey which had begun as a one-off job became an office of government and the surveys in India and in the US and in Canada are extremely good examples of that. So that what we see in the 19th century is alongside Alan's heroic amateurs

the emergence of a relatively large-scale astronomical profession. You could pursue your career working for the government as an observer. This is perfectly true, but of course also we have to ask what kind of astronomy is being done. When you look at what's being done in India, at Parramatta, at the Cape and all of these places, it's all pretty well regulatory surveying stuff of the kind being done by Cook. But when you look at the really adventurous astronomy of the 19th century, astrophysics determining the gravitational relationships of binary stars is the universe infinite, these immensely philosophical and captivating issues.

Not a brass penny is being paid for here by the government. And this is, of course, where the amateurs are actually coming in. And of course, in pure research, what we would know call pure research, which of course is often done overseas because, of course, Lassel, for instance, wants to steal a lead on Harvard. And Harvard is closer to the Earth's surface, closer to the equator than we are. So he takes his giant telescope to Malta, which steals the lead on William Cranch Bond in Harvard.

And you had the immense fortune of a master brower in Liverpool, who is hot on the quest of astronomical physics, taking a vast instrument to Malta for five years. And there are others like him. But of course, what these men are doing is not the kind of stuff being done at the Cape or at Toronto. This is absolute cutting-edge astrophysics. Can we come?

Beyond that, there is almost, I mean, it may be a heretical story, but there seems to have been almost an antipathy between the professional astronomers and the amateurs. And there is a story, and I'm sure Alan Winonault. if I've made this up or not. But it's mythology that when Herschel came to visit George Erie, the seventh astronomer royal, at the observatory, and George Erie, who'd spent his whole life mapping the heavens,

met him, says, well, what are you working on? Herschel says, well, I'm trying to figure out how the universe started, what stars are made of. And Erie just said, that's nonsense. Why would anyone want to do that? Our job is to map stars. I personally wouldn't quite agree with that. Not only that because Aery and Herschel were friends from undergraduate days in Cambridge.

They even swapped children because occasionally the Aery children went to live. Yes, the Aerie girls actually went to live for some time in Kent to learn the social graces at the great Herschel household. He could have just meant that it wasn't the job of the observatory. Well, what Aerey certainly says in 1881 very, very clearly, is that all the great innovations in pure research have been made in the amateur front. and he says it's the job of public money to do what he's useful to the state.

Cartography, chronometers, but O'Hershal and Eri were friends for half a century. Christine, can I just ask about the returning to the transit of Venus, partly because it's just a wonderful prize. In the late 90th century, the Venus was calculated to go across the sun in 1874 and 1882. Was there great expeditions were still going out?

Were there? Was there still great interest? Well, I think picking up on what Simon was saying about the surveys is it comes to a point in the late 19th century where it's almost the duty of an empire to have astronomical expeditions. And certainly for the 1874 expedition, there were 62 different expeditions from the UK, from the US, from Russia, who sent 26 different sets of people out, France, Germany, Italy, Holland. So it comes to a point that if you are an empire or have any imperial aspirations, you go and conquer space. You know, it's this idea we must go measure as an empire. Tony, Simon. I think one of the things that's very important to remember is that without imperial infrastructure,

expeditions are fantastically difficult to mount. So that the great expeditions of the later 19th century, both to observe the transit of Venus and also to observe the exact. eclipses of the sun rely overwhelmingly on the prior existence in these sites of railroads, of steamship lines, of certainly in the subcontinent in India, troops to guard astronomical bases. So I think one of the things that's very interesting is that you begin to see the feedback between the prior existence of colonial networks, which allow European astronomers to travel and act reliably, and the contribution that that astronomy is making

to the security of those networks. Unfortunately, we're coming towards the end of this programme, which is a bit of a pity, but there you go. I want to finish on, Christine Lippincott. In 1990s, Sir Arthur Eddington sailed, the Atlantic made observations which confirmed Einstein's theory of relativity. Can you give us a little bit of information about that? And then maybe one or two of your comment

and whether that was the last symbolic of the end of the relationship between astronomy and the British Empire. So, tall order in short time, Chris. give you a very in a nutshell and people will call in and complain. Essentially the idea is if Einstein was right, then when there is a solar eclipse, the stars that are on the outside of the darkened sun, the light will appear to bend. Eddington went out there and found out that the light did bend, therefore Einstein was right. Now why this was important? Because in 1919, that's six months after the end of the First World War. And the German scientists were being boycotted by

the British. And Eddington, who was a Quaker and was a pacifist, said, no, we must keep science open for all. And the fact that an Englishman went out and proved right, a German was seen as an international peaceful gesture. And you see that as bringing this to a close, don't you? I think the Eddington... Because Eddington, in a sense, made Einstein famous. That's absolutely true. It's been shown that the public announcement of Eddington's, astonishing results from the South Atlantic was indeed what made Einstein an international hero. All of a sudden, Einstein was news. He'd not been news before the First World War. There's much more to say about that, and we don't, in an Einsteinian way, have time to say it.

For example, another of Einstein's predictions, which was that the light from stars will shift to the red because of gravity. where was that first demonstrated at a British colonial observatory in southern India at Kodi Canal, high in the Western Ghats? So it seems to me, yes, that these projects bring to an end that very long-term relationship that they had up till then always been between the colonial networks and the triumphs of precision astronomy. Briefly, Alan, you're bursting to get in.

Yes? I wouldn't quite agree. I think perhaps it was the last great discovery of major world importance. But of course, since then, you've had, let's say, the Radcliffe Observatory in Oxford relocating to South Africa. And also the wider question of was imperialism bad? I think what it actually did do was to spread a great deal

of very, very useful information around the globe. Thank you very much. Fairies next week. Thanks for listening. We hope you've enjoyed this Radio 4 podcast. You can find hundreds of other programmes about history, science and philosophy at BBC.com.uk forward slash radio 4.