0:00:10 > 0:00:18300 years ago, a group of men found themselves thousands of miles from home, fighting for their lives.
0:00:18 > 0:00:25They had travelled halfway around the world, across unknown lands into hostile territory.
0:00:31 > 0:00:34But these were no hardened adventurers.
0:00:34 > 0:00:39They were bookish academics on one of the most important scientific expeditions ever.
0:00:43 > 0:00:48Its outcome would fundamentally change the way we see our world.
0:00:50 > 0:00:57But their mission would become an eight-year epic of obsession, betrayal and murder.
0:01:17 > 0:01:20History is littered with explorers
0:01:20 > 0:01:25who are driven by a desire for wealth and glory.
0:01:25 > 0:01:28But the men on this expedition were different.
0:01:28 > 0:01:30They were scientists,
0:01:30 > 0:01:35and this was the first scientific expedition ever.
0:01:38 > 0:01:42The ambitious mission was launched in 1735
0:01:42 > 0:01:47to discover a fundamental truth about our planet...
0:01:48 > 0:01:51..the true shape of the Earth.
0:01:56 > 0:01:59I'm not short of ambition myself.
0:01:59 > 0:02:01I've climbed on Everest,
0:02:01 > 0:02:05and run countless expeditions in polar regions.
0:02:05 > 0:02:08But even by my standards,
0:02:08 > 0:02:13this French mission was an amazingly ambitious project.
0:02:16 > 0:02:20And I've always had modern equipment and modern back-up and support.
0:02:22 > 0:02:25These scientists didn't know what they were getting into.
0:02:28 > 0:02:30Their three-year plan
0:02:30 > 0:02:35involved sailing 10,000 kilometres from France to the equator...
0:02:35 > 0:02:39scaling the Andes and crossing dense rainforest.
0:02:43 > 0:02:45It was a bold plan to begin with
0:02:45 > 0:02:49but it would turn out to be much more daunting than they could have imagined.
0:02:49 > 0:02:54They'd be plagued by disease and death.
0:02:54 > 0:02:58Instead of taking three years, it would take them nine.
0:03:01 > 0:03:08But, for all that, they would make a series of chance discoveries that would have a profound impact.
0:03:09 > 0:03:12From maps and medicinal cures,
0:03:12 > 0:03:16to rubber goods and the metric system.
0:03:18 > 0:03:21This is the story of their incredible journey,
0:03:21 > 0:03:25carefully pieced together from their own journals.
0:03:34 > 0:03:39"We sailed from La Rochelle in the month of May 1735,
0:03:39 > 0:03:42"provided with passports from His Catholic Majesty Philip V,
0:03:42 > 0:03:45"for the purpose of taking measurements next to the equator."
0:03:45 > 0:03:50C'est tres bien, quand meme. C'est un des meilleurs de Paris.
0:03:50 > 0:03:53Si on continue comme ca on va etre en retard.
0:03:53 > 0:03:56Merci bien, Monsieur.
0:03:57 > 0:04:03A team of men loaded their ship, the Portefait, with state-of-the-art scientific instruments.
0:04:12 > 0:04:16And leading the expedition were some of France's greatest brains.
0:04:19 > 0:04:22Pierre Bouguer, aged 37.
0:04:22 > 0:04:30A mathematician who had been a child prodigy, and was made a Royal Professor at just 16 years of age.
0:04:34 > 0:04:36Charles-Marie de la Condamine.
0:04:36 > 0:04:38Aged 34.
0:04:38 > 0:04:42A wannabe adventurer with four years' experience in the military.
0:04:48 > 0:04:50And Louis Godin.
0:04:50 > 0:04:53Ambitious mathematician and astronomer.
0:04:53 > 0:04:56At 31, he was the youngest of the three,
0:04:56 > 0:05:00but he'd appointed himself leader
0:05:00 > 0:05:04on the grounds he'd suggested the expedition in the first place.
0:05:10 > 0:05:14With their delicate scientific instruments and elegant attire,
0:05:14 > 0:05:17these men were the very antithesis of rugged explorers.
0:05:20 > 0:05:22Merci. ..Ne touche pas!
0:05:22 > 0:05:26Je pense que c'est vivant! Oui!
0:05:26 > 0:05:29Ca vient d'un des meilleurs fabricants en Paris.
0:05:29 > 0:05:32Bien sur, bien sur!
0:05:32 > 0:05:34Voila, Monsieur. Ah, Monsieur!
0:05:34 > 0:05:37Vous etes prets? Oui, oui. Tres bien.
0:05:37 > 0:05:41Messieurs, on est pret a partir.
0:05:41 > 0:05:45The team had barely travelled beyond the boulevards of Paris,
0:05:45 > 0:05:48and now they were heading off to the other side of the world.
0:06:01 > 0:06:05The mission the French scientists were charged with was a huge one.
0:06:05 > 0:06:10Nothing less than to measure the shape of the entire Earth.
0:06:17 > 0:06:23For centuries, people thought the Earth was a sphere, a perfect ball floating in space.
0:06:23 > 0:06:27One unusual measurement would change that notion.
0:06:31 > 0:06:35When Louis XIV, the King of France, wanted a new map of his country,
0:06:35 > 0:06:40he got the famous Italian astronomer Cassini to do the job.
0:06:40 > 0:06:44Cassini noticed something really odd. Up in the north of the country
0:06:44 > 0:06:47a degree of latitude was a different length
0:06:47 > 0:06:51than a degree of latitude in the south of the country.
0:06:51 > 0:06:56So this suggested something really shocking - that the Earth wasn't a perfect sphere at all.
0:07:01 > 0:07:06So, Cassini's measurements led him to believe that the Earth was kind of egg-shaped.
0:07:06 > 0:07:10And, suddenly, everyone came up with their version of the shape of the Earth.
0:07:10 > 0:07:15Amongst them was Isaac Newton, whose theories of gravity suggested to him
0:07:15 > 0:07:19that the Earth was much flatter, kind of grapefruit-shaped.
0:07:26 > 0:07:29It had become the burning issue of the day.
0:07:29 > 0:07:32This was the age of the Enlightenment,
0:07:32 > 0:07:35an era which was fanatical about knowledge,
0:07:35 > 0:07:38and knowing the shape of our planet was critical.
0:07:38 > 0:07:45The row between Cassini and Newton had become so fierce that this group of men were sent out to settle it.
0:07:48 > 0:07:54And that would take nothing less than a practical measurement of the curvature of the Earth.
0:07:56 > 0:07:59This expedition was completely unprecedented.
0:07:59 > 0:08:05It represented the very pinnacle of the Enlightenment, the new age of experimental science.
0:08:05 > 0:08:10Scientists themselves called it "the greatest expedition that world had ever seen".
0:08:18 > 0:08:24Fired by academic fervour, they headed off to the equator in Peru - now Ecuador.
0:08:27 > 0:08:33For the three chief scientists, this was their opportunity to shine.
0:08:33 > 0:08:36Bouguer might recover some of the faded glory of his youth,
0:08:36 > 0:08:43while La Condamine and the ambitious Godin might make their reputations.
0:08:44 > 0:08:50And, for this, they were prepared to give three years of their lives.
0:08:55 > 0:09:00But, soon after setting sail, they were about to make their first big mistake.
0:09:08 > 0:09:14After five weeks at sea, the group stopped off at Santo Domingo in the Caribbean.
0:09:20 > 0:09:23This was the perfect place to test their instruments
0:09:23 > 0:09:26and wait for the letters of permission
0:09:26 > 0:09:31to be exchanged back and forth between the French diplomats and the Spanish, who ruled Peru.
0:09:31 > 0:09:34They had some time on their hands -
0:09:34 > 0:09:36time to enjoy the relaxed surroundings.
0:09:40 > 0:09:44This French colony would have seemed to them a paradise,
0:09:44 > 0:09:47filled with exotic and beautiful people.
0:09:49 > 0:09:53As soon as Godin, the expedition's self-appointed leader,
0:09:53 > 0:09:59set foot on land, he set his heart on a local woman, named Gousan.
0:10:04 > 0:10:08As one of the crew wrote in a letter at the time...
0:10:08 > 0:10:11"Love is taking up all his time.
0:10:11 > 0:10:15"I hope that his wife doesn't hear of her Adonis's infidelity.
0:10:15 > 0:10:17"She will perhaps take revenge.
0:10:17 > 0:10:23"It is very annoying that honest people are at the mercy of a young beard without experience."
0:10:26 > 0:10:29Even back in the 18th century,
0:10:29 > 0:10:34Godin knew exactly who - or rather what - were a girl's best friend.
0:10:39 > 0:10:43But this gift was to bring nothing but trouble.
0:10:46 > 0:10:50Unfortunately, Godin hadn't used his own money to buy the diamond.
0:10:50 > 0:10:54As leader of the group, he had control of the expedition coffers.
0:10:56 > 0:11:01And it was this, the expedition's money, that Godin had squandered.
0:11:03 > 0:11:10He'd spent a whopping 1,000 ecus, which is about ?23,000 today!
0:11:10 > 0:11:14So this extravagance had just put the whole expedition under threat.
0:11:18 > 0:11:22To lose so much money at this early stage was a disaster.
0:11:22 > 0:11:26The remainder was barely enough to get to Peru.
0:11:27 > 0:11:34Failure at this stage would mean returning home to face humiliation and the end of their careers.
0:11:53 > 0:11:56The other scientists, La Condamine and Bouguer,
0:11:56 > 0:12:00were furious about Godin's extravagance with their money.
0:12:21 > 0:12:27Seniergue, the expedition surgeon, described the escalating tension in a letter home.
0:12:30 > 0:12:36"Mr Godin has not been speaking to Mr de la Condamine and Mr Bouguer for some time now.
0:12:38 > 0:12:43"They fight like cats and dogs, and attack each other's observations."
0:12:43 > 0:12:45Merci.
0:12:45 > 0:12:50"It is not possible that they will remain together for the rest of this trip."
0:12:53 > 0:12:56What should have been a close-knit team,
0:12:56 > 0:12:59gearing up for a challenging expedition,
0:12:59 > 0:13:01became a bickering band of rivals.
0:13:08 > 0:13:10And they hadn't even reached Peru yet.
0:13:18 > 0:13:22Now they had to go right through to the heart of Peru to reach the equator.
0:13:22 > 0:13:27And that whole area, particularly round the Amazon, was completely uncharted.
0:13:27 > 0:13:29Few Europeans had been there.
0:13:29 > 0:13:32It was a monumental task for any group.
0:13:32 > 0:13:35But, for men who were not only desperately short of money
0:13:35 > 0:13:39but not even speaking to each other, it seemed impossible.
0:13:48 > 0:13:53Finally, on March 10th 1736, they reached Peru.
0:13:56 > 0:14:00But they couldn't proceed without more money.
0:14:00 > 0:14:02And so they headed to the area's capital, Quito,
0:14:02 > 0:14:06hoping they might borrow funds from the Spanish authorities there.
0:14:10 > 0:14:13To reach Quito, the expedition had to go inland,
0:14:13 > 0:14:17across hundreds of kilometres of uncharted land,
0:14:17 > 0:14:21and handle some very unfamiliar terrain.
0:14:24 > 0:14:27One ticket, please. Una billet, por favor.
0:14:35 > 0:14:36Hola!
0:14:43 > 0:14:45People use these every day for work.
0:14:48 > 0:14:52It's the normal form of transport across these whopping great gorges.
0:15:00 > 0:15:06They wouldn't have seen anything like this in the comfortable boulevards of Paris.
0:15:06 > 0:15:09I mean, this would have been totally unfamiliar terrain for them.
0:15:09 > 0:15:12250ft-deep gorges,
0:15:12 > 0:15:14huge waterfalls,
0:15:14 > 0:15:18and they believed - quite rightly because they had no other knowledge -
0:15:18 > 0:15:22that all this unfamiliar terrain and hidden in these trees were monsters.
0:15:22 > 0:15:27Headless monsters, one-eyed cannibals, all kinds of terrible things.
0:15:30 > 0:15:34Whatever creatures they imagined, real dangers lurked in these forests.
0:15:36 > 0:15:41From bears and snakes to more insidious killers...
0:15:41 > 0:15:44insects carrying deadly diseases.
0:15:47 > 0:15:53On top of these threats, now the French scientists unwittingly made their journey even more difficult.
0:16:00 > 0:16:04They hadn't been speaking to each other for ages.
0:16:04 > 0:16:09And now they decided they'd just had enough, and they were just going to travel separately.
0:16:09 > 0:16:12All the way to Quito. Seems a crazy thing to do.
0:16:12 > 0:16:16It's certainly breaking one of the golden rules of travel.
0:16:20 > 0:16:27Godin commandeered the equipment and the guides, with Bouguer following shortly behind,
0:16:27 > 0:16:32leaving La Condamine to cross through one of the world's most hostile environments alone.
0:16:35 > 0:16:38And I'm following in his footsteps.
0:16:50 > 0:16:57La Condamine canoed up the coast, and then up here - the Esmeraldas River - so he could get inland.
0:16:57 > 0:17:00And he had a real genuine interest for exploring.
0:17:00 > 0:17:04And this would have been a complete treasure trove for him.
0:17:04 > 0:17:09Round every bend in this river there would've been something new. He'd be bursting to understand it.
0:17:16 > 0:17:23It wasn't long before his curiosity led him to the first significant discovery of the expedition.
0:17:29 > 0:17:33As La Condamine made his way through the jungle, he came across a group
0:17:33 > 0:17:38of local Quechua Indians, and they were collecting sap from the trees.
0:17:44 > 0:17:46It was a strange pliable substance,
0:17:46 > 0:17:50the like of which La Condamine had never seen before.
0:17:53 > 0:17:59"When fresh, by means of moulds, it takes any shape given to it at pleasure.
0:17:59 > 0:18:05"It is impervious to rain but its most remarkable property is its elasticity.
0:18:07 > 0:18:10"Of it are made infrangible bottles, boots
0:18:10 > 0:18:13"and hollow balls, which can be flattened at will,
0:18:13 > 0:18:17"but which, when the pressure that flattens them is removed,
0:18:17 > 0:18:19"assume again their pristine form."
0:18:29 > 0:18:32La Condamine had chanced across rubber.
0:18:39 > 0:18:45Montserrat Rios is an ethno-botanist, studying how the local Quechua people use rubber.
0:18:45 > 0:18:48Arturo? Quechua Indian? Wow.
0:18:48 > 0:18:52Arturo Grefar is an expert rubber tapper.
0:18:52 > 0:18:56The way to collect the rubber is that you have to cut a V on the trunk.
0:18:56 > 0:19:00So the rubber is right up in between the bark and the tree itself?
0:19:00 > 0:19:03Yes. OK.
0:19:03 > 0:19:05So the local people were doing this
0:19:05 > 0:19:07when La Condamine came through?
0:19:07 > 0:19:10Yes, this is a very old practice, since pre-Hispanic.
0:19:10 > 0:19:15And it's the same practice now...? It's the same practice now for thousands of years. OK.
0:19:15 > 0:19:17Arturo, can I have a go?
0:19:19 > 0:19:22Thanks very much. OK, stand back.
0:19:28 > 0:19:30That's a bit rough...
0:19:30 > 0:19:32And another one?
0:19:32 > 0:19:33Another one, like this.
0:19:45 > 0:19:48Blimey, it looks a bit untidy. Well...
0:19:48 > 0:19:50It's not as good as yours!
0:19:50 > 0:19:55So Arturo, once you've collected the rubber, what do you do with it then?
0:19:55 > 0:20:00He collect the rubber and then he make balls, rubber balls. Right.
0:20:00 > 0:20:03So, hang on. Oh, I've got the idea. OK, it picks it up.
0:20:03 > 0:20:05It kind of picks it up.
0:20:08 > 0:20:11It's a long process, though. You just keep doing that?
0:20:11 > 0:20:13Yes, it's a long process.
0:20:13 > 0:20:14It takes flipping ages.
0:20:17 > 0:20:21Arturo, what do you do with the rubber you collect?
0:20:31 > 0:20:37I love it. La Condamine came through here and discovered something that revolutionised Europe in many ways.
0:20:37 > 0:20:40It was a tremendous discovery for us 300 years ago.
0:20:40 > 0:20:44And yet, Arturo and his people, it's completely routine.
0:20:46 > 0:20:51La Condamine immediately recognised the potential of this extraordinary new material.
0:20:51 > 0:20:56He sent back the first specimens of rubber seeds and wrote a meticulous paper.
0:20:56 > 0:20:59That prompted the rubber boom of the Victorian era,
0:20:59 > 0:21:03creating millionaires and shaping empires.
0:21:05 > 0:21:09So, thanks to La Condamine sending back the rubber samples and writing his papers,
0:21:09 > 0:21:13he kick-started the rubber industry as we know it today.
0:21:13 > 0:21:18So we've got him to thank for rubber tyres, windscreen wipers,
0:21:18 > 0:21:23inflatable rubber boats, washing-up gloves, condoms...
0:21:24 > 0:21:27I wonder if they were originally called La Condamines!
0:21:32 > 0:21:35Things seemed to be looking up for La Condamine.
0:21:35 > 0:21:42He'd discovered rubber, and he was now on his way to Quito to join the rest of his expedition.
0:21:42 > 0:21:46But the reality was a bit different.
0:21:46 > 0:21:50He was lost in this rainforest.
0:21:55 > 0:22:00Even worse, his two guides had just taken off.
0:22:00 > 0:22:02So now he was alone...
0:22:03 > 0:22:07..except for the company of jaguars,
0:22:07 > 0:22:09pumas,
0:22:09 > 0:22:11tarantulas
0:22:11 > 0:22:13and poisonous snakes.
0:22:33 > 0:22:37And this is what he was up against -
0:22:37 > 0:22:40a solid wall of rainforest.
0:22:40 > 0:22:45It's really hard work to get through, even with a sharp machete like my one.
0:22:45 > 0:22:50La Condamine just had an axe, and he had no jungle experience whatsoever.
0:22:50 > 0:22:52And neither do I.
0:22:52 > 0:22:58And everything seems to be so intent on biting or poisoning
0:22:58 > 0:23:00or scaring the pants off me.
0:23:04 > 0:23:09He would have recognised things like bananas, thank heaven, and they were the things that kept him alive.
0:23:09 > 0:23:13Everything else, just like me, seems so alien.
0:23:13 > 0:23:15It gives me the willies!
0:23:17 > 0:23:18I'm not joking!
0:23:21 > 0:23:25After a few days, La Condamine developed a raging fever.
0:23:25 > 0:23:30And it could have been any one of countless fatal diseases.
0:23:30 > 0:23:33Chances were
0:23:33 > 0:23:36he would die here alone.
0:24:01 > 0:24:03While La Condamine was lost in the jungle...
0:24:05 > 0:24:10..the rest of the expedition had safely arrived in the city of Quito.
0:24:12 > 0:24:14And, with the expedition virtually penniless,
0:24:14 > 0:24:18Godin tried to address the money problems that HE had created.
0:24:20 > 0:24:23He met with the local Spanish governor, El Sado,
0:24:23 > 0:24:28and he asked him for the money the expedition so desperately needed.
0:24:28 > 0:24:32But El Sado flatly refused.
0:24:36 > 0:24:38It was a blow, as the most powerful and wealthy man
0:24:38 > 0:24:43in the area - Dionisio El Sado - was their only hope.
0:24:45 > 0:24:48Now the French scientists were stuck.
0:24:48 > 0:24:51They had no choice but to wait for La Condamine
0:24:51 > 0:24:56and hope that his higher social status would help them persuade El Sado.
0:25:01 > 0:25:06After eight days of terrible sickness and surviving only on bananas,
0:25:06 > 0:25:10La Condamine's luck finally turned when his fever broke.
0:25:10 > 0:25:13He spotted a mountain peak and decided to follow it.
0:25:22 > 0:25:26"Having reached the highest point of the edge, I was seized by a sense of wonder,
0:25:26 > 0:25:31"mixed with admiration, at the appearance of a large valley.
0:25:31 > 0:25:34"The city of Quito, far off,
0:25:34 > 0:25:37"was at the end of this beautiful view."
0:25:39 > 0:25:43Unbelievably, La Condamine had survived.
0:25:43 > 0:25:46With Quito in sight, he was saved.
0:25:49 > 0:25:54As he entered the city, all hopes of saving the mission rested on him.
0:25:57 > 0:25:59But, instead of going off to see El Sado
0:25:59 > 0:26:05and making the essential request for the money on which the whole expedition depended,
0:26:05 > 0:26:08La Condamine hid himself away in his rooms,
0:26:08 > 0:26:09and wouldn't come out.
0:26:14 > 0:26:18Everyone waited for La Condamine to announce himself.
0:26:18 > 0:26:21But, day after day, nothing.
0:26:23 > 0:26:27El Sado grew increasingly incensed.
0:26:27 > 0:26:31Why did this foreigner not announce himself?
0:26:31 > 0:26:35Was he too arrogant, too superior?
0:26:35 > 0:26:40The whole mission, even their ability to get home, was hanging on a thread.
0:26:42 > 0:26:47"Given that I had only taken with me my instruments, a hunting outfit and a hammock,
0:26:47 > 0:26:54"I found myself incapable of appearing in public in any decent fashion when I arrived in Quito.
0:26:54 > 0:27:00"And, although our companions had used 17 mules to carry cargo, as well as persons,
0:27:00 > 0:27:06"it had not been possible in my absence to find a place for a single one of my trunks.
0:27:06 > 0:27:08"Not even for my bed."
0:27:22 > 0:27:25It was a full week before La Condamine was able to see El Sado.
0:27:51 > 0:27:55In this very room La Condamine finally got to meet El Sado.
0:27:55 > 0:28:00El Sado demanded to know why he hadn't been to see him before.
0:28:00 > 0:28:07La Condamine answered, he couldn't possibly meet a man of such stature and importance dressed in rags.
0:28:07 > 0:28:12Very cleverly, he turned a moment of gross insult into flattery.
0:28:13 > 0:28:17"I completely satisfied the president on all counts.
0:28:17 > 0:28:23"And since this first conversation, I am able to count on his family's friendship and trust."
0:28:25 > 0:28:27Well, up to a point.
0:28:27 > 0:28:30In fact, El Sado didn't give him a single penny.
0:28:30 > 0:28:34He did allow La Condamine one concession -
0:28:34 > 0:28:39the dubious honour of opening up a shop in Quito, where he could sell his belongings.
0:28:39 > 0:28:42It was all a bit humiliating for La Condamine,
0:28:42 > 0:28:46but he did manage to sell enough to get by for a few weeks.
0:28:56 > 0:29:02What had seemed to La Condamine like a victory left them hardly any better off.
0:29:04 > 0:29:1118 months into their expedition, 10,000 kilometres from home, and almost completely broke,
0:29:11 > 0:29:15and they hadn't even made one scientific measurement yet.
0:29:15 > 0:29:20It seemed as if their hopes of scientific glory were in tatters.
0:29:20 > 0:29:24And things were about to get much worse.
0:29:30 > 0:29:34Having exhausted all options for raising money in Quito,
0:29:34 > 0:29:38they were forced to start their measurements with what meagre funds they had.
0:29:38 > 0:29:42So, they headed off into the wilderness towards the equator.
0:29:46 > 0:29:50Within days, Couplet, the youngest member of the team, collapsed.
0:29:55 > 0:30:00The expedition surgeon, Seniergue, suspected malaria and administered
0:30:00 > 0:30:04the most popular treatment of the time - bleeding and purging.
0:30:26 > 0:30:30When this didn't work, the poor lad was treated to a local cure.
0:30:36 > 0:30:39"A lemon stuffed with gunpowder and guinea pepper
0:30:39 > 0:30:45"is insinuated into the anus, and changed two or three times a day...
0:30:47 > 0:30:51"..until the patient is judged to be out of danger."
0:31:06 > 0:31:11Despite - or even because of - these treatments, young Couplet died two days later.
0:31:13 > 0:31:16It was a harsh reminder of the ever-present threat
0:31:16 > 0:31:20of disease and death that hung over them all in this alien land.
0:31:23 > 0:31:27What's more, Godin, Bouguer and La Condamine were now a man down,
0:31:27 > 0:31:30with all their work still ahead of them.
0:31:37 > 0:31:42The men were upset by Couplet's death, but it didn't knock 'em off track.
0:31:42 > 0:31:46Partly because they were such determined men, and partly because
0:31:46 > 0:31:50early death was a pretty familiar occurrence in those days.
0:31:50 > 0:31:52Life had to go on.
0:31:52 > 0:31:57But before the expedition could continue, they had to sort out their desperate money problems.
0:31:57 > 0:32:01So La Condamine came up with a remarkable plan.
0:32:01 > 0:32:08Despite his earlier problems in the rainforest, he volunteered to go across to Lima to raise some funds.
0:32:08 > 0:32:14And that would be a whopping distance of 2,000 kilometres.
0:32:19 > 0:32:24'Unbelievably, La Condamine was about to set off alone again.
0:32:24 > 0:32:29'His determination was either foolhardy or incredibly brave.'
0:32:29 > 0:32:33Looking around, I can see it's mostly fields.
0:32:33 > 0:32:35It's all cultivated.
0:32:35 > 0:32:38And it looks relatively gentle.
0:32:38 > 0:32:42But in La Condamine's time, this was all rainforest,
0:32:42 > 0:32:45and it would have been even harder to get round.
0:32:45 > 0:32:47It's hard enough now.
0:32:48 > 0:32:54On this second trek across country, he made another significant discovery.
0:32:54 > 0:32:59He saw people harvesting a natural chemical - quinine - from the bark of cinchona trees.
0:32:59 > 0:33:01And he was intrigued.
0:33:05 > 0:33:09In the 18th century, malaria was still endemic in Europe.
0:33:09 > 0:33:12Quinine was known as a treatment there,
0:33:12 > 0:33:18but it was surrounded in mystery, because sometimes it worked and sometimes it didn't.
0:33:19 > 0:33:24'Botanist Pablo Lozano took me to a cinchona tree to explain why.'
0:33:26 > 0:33:28OK. Well done!
0:33:28 > 0:33:34You have a red bark, and there is another two kinds of bark.
0:33:34 > 0:33:39A yellow and a white one. OK.
0:33:39 > 0:33:42Same cinchona tree... but different bark.
0:33:42 > 0:33:46Another species of cinchona. Different species. OK.
0:33:46 > 0:33:48So now, if I was to take...
0:33:48 > 0:33:53a little bit of this, this would protect me from malaria, right? Yes.
0:33:56 > 0:33:58It's bitter.
0:33:58 > 0:34:01You're lucky, because this is the red bark.
0:34:01 > 0:34:05It has the highest content of quinine.
0:34:05 > 0:34:11In the 18th century, there was a confusion of the species.
0:34:13 > 0:34:17Here in Peru, the locals knew that, of the three distinct species of cinchona,
0:34:17 > 0:34:22only this one, with red bark, was effective against malaria.
0:34:22 > 0:34:24But in Europe, they didn't know this.
0:34:24 > 0:34:30So the Peruvians and merchants made a good trade, sending any old bark to unsuspecting Europeans.
0:34:33 > 0:34:36So La Condamine came through and picked up that
0:34:36 > 0:34:40out of the three types, one of them was better than the rest?
0:34:40 > 0:34:46Yes, he spent three days talking with the local people,
0:34:46 > 0:34:51and he identified the real species - the red bark.
0:34:51 > 0:34:58I think that's fantastic that, in just three days, he'd discovered this fantastically important thing.
0:35:01 > 0:35:04La Condamine wrote up what he'd learnt from the locals,
0:35:04 > 0:35:08with meticulous drawings, and sent it back to France.
0:35:12 > 0:35:17For the first time, doctors were able to use quinine reliably,
0:35:17 > 0:35:22and for the next 200 years, it became the only effective treatment for malaria,
0:35:22 > 0:35:25saving millions of lives.
0:35:28 > 0:35:32Had La Condamine made his great discovery just a few weeks earlier,
0:35:32 > 0:35:36then young Couplet might have been saved from dying of malaria.
0:35:43 > 0:35:49La Condamine continued onto Lima, on his quest to get money for the impoverished expedition.
0:35:51 > 0:35:56Out of the whole French team, it's La Condamine I have the most affinity to,
0:35:56 > 0:35:58cos he really wanted to be an explorer.
0:35:58 > 0:36:01And I think that he had a genuine love
0:36:01 > 0:36:07of that feeling of adventure and new places...that I have.
0:36:07 > 0:36:10But he had a real sense of adventure,
0:36:10 > 0:36:15a certain flair. There was a lovely spark within him.
0:36:20 > 0:36:24'La Condamine's daring paid off once again when he got to Lima.
0:36:24 > 0:36:27'He secured a generous loan of 12,000 pesos -
0:36:27 > 0:36:31'the equivalent of ?230,000 today.
0:36:35 > 0:36:39'He returned triumphant to greet Bouguer and Godin.
0:36:39 > 0:36:44'At last, they had sufficient funds, and they could begin their measurements.
0:36:56 > 0:37:01'Finally, after 18 months, after illness,
0:37:01 > 0:37:04'a death and the loss of their funds,
0:37:04 > 0:37:07'they had reached the equator - their destination.'
0:37:11 > 0:37:13I'm here at the equator.
0:37:13 > 0:37:16If I jump here, I'm in the northern hemisphere.
0:37:16 > 0:37:18If I jump here, this is the southern hemisphere.
0:37:20 > 0:37:23The equator was their reason for travelling to Peru.
0:37:23 > 0:37:28It was the very heart of their plan to measure the curvature of the Earth.
0:37:35 > 0:37:39Their mission was to come here to the equator and measure the degree of latitude,
0:37:39 > 0:37:42and compare that to a measurement
0:37:42 > 0:37:45that was already known north up in France.
0:37:45 > 0:37:48And by looking at the difference between the two,
0:37:48 > 0:37:51they could determine the true shape of the Earth.
0:37:52 > 0:37:55'It sounds simple on paper.'
0:37:55 > 0:37:57Beautiful!
0:37:57 > 0:38:01But this plan would require climbing some of the world's largest mountains.
0:38:21 > 0:38:25The Andes formed a crucial part of the measurements.
0:38:25 > 0:38:30The first stage of measuring a degree of latitude
0:38:30 > 0:38:35was to measure a long line, hundreds of miles long, across the equator.
0:38:35 > 0:38:40And in this rugged terrain, it's not the kind of thing you can do with a tape measure.
0:38:49 > 0:38:53'Instead, they would calculate the length of the line mathematically,
0:38:53 > 0:38:56'using the heights of the Andes for sightings.'
0:38:58 > 0:39:02So the plan was to use triangulation,
0:39:02 > 0:39:05which is straightforward trigonometry.
0:39:08 > 0:39:11Here's the equator,
0:39:11 > 0:39:17and they needed to measure a line right down the length of the Andes, hundreds of miles long.
0:39:17 > 0:39:21And they would climb... three peaks
0:39:21 > 0:39:25and put markers on top of them
0:39:25 > 0:39:30that could be clearly seen from the other mountains.
0:39:30 > 0:39:34Then they would measure these angles.
0:39:38 > 0:39:40And because they knew all the angles,
0:39:40 > 0:39:44they could easily calculate the distance between the mountains.
0:39:44 > 0:39:47So they'd climb more mountains and measure more angles,
0:39:47 > 0:39:53and continue this chain of triangles, down the whole length of the Andes.
0:39:53 > 0:39:59And, that way, they could accurately measure a line hundreds of miles long.
0:39:59 > 0:40:03They would then take star sightings at each end of the line
0:40:03 > 0:40:08to find how many degrees of latitude this long line corresponded to.
0:40:08 > 0:40:12And, from this, they could calculate the length on the ground
0:40:12 > 0:40:18of a single degree of latitude, to reveal the shape of the Earth.
0:40:19 > 0:40:22ARGUING IN FRENCH
0:40:24 > 0:40:29While utterly committed to this scientific plan, their arguments continued.
0:40:29 > 0:40:32And so, they split up - again.
0:40:35 > 0:40:37Godin went his own way,
0:40:37 > 0:40:42while the more diligent Bouguer and La Condamine went another.
0:40:45 > 0:40:51And so these two groups set about climbing the Andes, mountain by mountain.
0:41:02 > 0:41:06Their first ascent proved to be a really tough opener.
0:41:06 > 0:41:10This is Pichincha, and it's a massive high volcano.
0:41:10 > 0:41:13It's almost 4,800 metres high.
0:41:13 > 0:41:16They had no idea of the scale of this thing.
0:41:16 > 0:41:20They didn't know what they were letting themselves in for,
0:41:20 > 0:41:22which I think's probably a good thing.
0:41:22 > 0:41:25Maybe if they had known, they wouldn't have come.
0:41:28 > 0:41:30'They struggled up towards the peak,
0:41:30 > 0:41:33'where they planned to plant a marker for their first sight line.'
0:41:41 > 0:41:45As they got higher, the conditions just got worse and worse.
0:41:47 > 0:41:48As they got near the top...
0:41:50 > 0:41:54..they just couldn't see anything - just like us now!
0:41:56 > 0:41:59But still, they kept on going.
0:42:01 > 0:42:03As they climbed higher,
0:42:03 > 0:42:06they started to feel really odd.
0:42:06 > 0:42:08They got ill,
0:42:08 > 0:42:15started to get headaches, they were nauseous and generally very, very weak indeed.
0:42:17 > 0:42:23"We found ourselves, at first, considerably incommoded by the rarefactions of the air.
0:42:23 > 0:42:27"Particularly those among us who had delicate lungs."
0:42:36 > 0:42:41What they didn't know was they were suffering from altitude sickness,
0:42:41 > 0:42:44and those effects are working on me right now.
0:42:44 > 0:42:47But I'm an experienced climber, so I know what to expect,
0:42:47 > 0:42:50and because I'm aware of that, I could make plans.
0:42:50 > 0:42:52I could put oxygen in place,
0:42:52 > 0:42:57I could have an altitude acclimatisation plan, and climb slowly.
0:42:57 > 0:43:01They knew none of these things, and just kept pushing on through
0:43:01 > 0:43:05the very dangerous effects of altitude sickness, which we now know can kill you.
0:43:18 > 0:43:22They finally made it here, to the summit,
0:43:22 > 0:43:26and conditions would have been pretty much like this.
0:43:26 > 0:43:29Cold and no visibility at all.
0:43:38 > 0:43:44As they struggled to plant the markers at the peak, they were blighted by even worse conditions.
0:43:54 > 0:43:57"We experienced extreme cold.
0:43:59 > 0:44:05"There, looking at each other, our clothes, eyebrows and eyelashes covered in icicles,
0:44:05 > 0:44:08"we provided each other with a singular spectacle."
0:44:13 > 0:44:19After surviving 23 days, and the most appalling conditions on the summit,
0:44:19 > 0:44:24they gave up, and came down here about halfway.
0:44:24 > 0:44:26It wasn't such a good position,
0:44:26 > 0:44:30but they could make their measurements and survive.
0:44:32 > 0:44:37It had taken them about four months to get one measurement.
0:44:37 > 0:44:40And they had 25 mountains left.
0:44:44 > 0:44:50'But driven by their scientific obsession, turning back was unthinkable.'
0:45:05 > 0:45:09Another day, another volcano.
0:45:09 > 0:45:13This is Cotopaxi, the world's highest active volcano.
0:45:13 > 0:45:17I've climbed this thing six times, and it's often like this.
0:45:17 > 0:45:21You can wait weeks for a decent weather window to get up.
0:45:31 > 0:45:35'As the conditions became more and more punishing,
0:45:35 > 0:45:40'it became clear that their mission would take far longer than they'd anticipated.
0:45:40 > 0:45:43'And yet, still they refused to give up.'
0:45:45 > 0:45:50They spent days or even months waiting for the weather to improve
0:45:50 > 0:45:52so they could continue with their measurements.
0:45:52 > 0:45:55So they'd plenty of time to think.
0:45:55 > 0:45:59And during that time, La Condamine came up with a great idea.
0:45:59 > 0:46:02But it was the last idea you would think of on top of a mountain.
0:46:05 > 0:46:09'It was an idea that would transform both science and everyday life,
0:46:09 > 0:46:13'and still impacts on us today.
0:46:13 > 0:46:16'It was the foundation of the metric system.
0:46:18 > 0:46:21'Larrie Ferreiro, a historian of science,
0:46:21 > 0:46:25'considers this one of La Condamine's most important contributions.'
0:46:25 > 0:46:29There he is! How are you? All right, thank you. What a fantastic market!
0:46:31 > 0:46:33It was a problem for many years.
0:46:33 > 0:46:37Villages, towns, cities, countries, didn't have standard measurements
0:46:37 > 0:46:42that allowed traders to go from one area to another and sell the same goods in different places.
0:46:42 > 0:46:46The inch was based on the thumb.
0:46:46 > 0:46:49That's my inch, from this joint to there.
0:46:49 > 0:46:51OK, so mine's bigger! Yes.
0:46:51 > 0:46:54We'd sell yours but buy mine! Yes.
0:46:54 > 0:46:59The yard was another one. The yard was ostensibly from the nose to the end of the hand.
0:46:59 > 0:47:03This is how you'd measure cloth. And this was a yard. OK.
0:47:03 > 0:47:07Let's have a little comparison then. Let's line up our noses up here.
0:47:07 > 0:47:09Yours is longer. Yes.
0:47:09 > 0:47:13If I was buying, I would want to be doing the measuring - not you. Yeah!
0:47:13 > 0:47:18What else was there? Well, the foot. Now, the foot was based on somebody's foot. Probably a king's foot.
0:47:18 > 0:47:21You have larger feet. I've got big feet,
0:47:21 > 0:47:24cos I'm small, but stable. OK. LAUGHTER
0:47:24 > 0:47:31'La Condamine, who worked constantly with weights and measures, saw that something had to be done.'
0:47:31 > 0:47:35What La Condamine had come up with was an idea that went beyond
0:47:35 > 0:47:39just the borders of cities and countries, but spanned the entire globe.
0:47:39 > 0:47:42Can you take a measurement based on the globe itself,
0:47:42 > 0:47:46and make a standard out of it and use that across the world?
0:47:46 > 0:47:52And he was the person who came up and fully developed an idea of a universal measurement.
0:47:53 > 0:47:58'This revolutionary idea was the basis for the metric system.
0:47:58 > 0:48:01'And, in 1793, the metre was defined
0:48:01 > 0:48:07'as one ten millionth of the distance from the North Pole to the equator.
0:48:09 > 0:48:13'La Condamine developed this idea over the many, many months
0:48:13 > 0:48:17'that the group struggled up and down the Andes, making their measurements.'
0:48:19 > 0:48:23After two years in the mountains, they had completed their triangulation -
0:48:23 > 0:48:28measuring a line hundreds of kilometres long down through the Andes.
0:48:28 > 0:48:31And although they'd never really pulled together as a team,
0:48:31 > 0:48:34as scientists, they were second to none.
0:48:34 > 0:48:41And even though they'd learnt the hard way, they'd finally become masters of the hostile environment.
0:48:41 > 0:48:46With the ground measurements in place, they just had some star sights left to do.
0:48:46 > 0:48:49So it seemed the end was in sight.
0:48:49 > 0:48:53But with this group, nothing was easy!
0:48:58 > 0:49:03'At the end of their triangulated line through the mountains was a town called Cuenca.
0:49:03 > 0:49:06'And they came here to carry out their star sightings.'
0:49:09 > 0:49:14And it was here that fate took a remarkable turn.
0:49:14 > 0:49:16I can barely believe what happened next.
0:49:30 > 0:49:32'The group were invited to a bull fight,
0:49:32 > 0:49:37'which, after years in the mountains, was a welcome spot of recreation.'
0:49:42 > 0:49:46I think I'm gonna... barely be able to watch it.
0:49:46 > 0:49:50But back then, it was a fantastic social occasion. Everybody came.
0:49:50 > 0:49:53The whole village would have turned out for this.
0:50:06 > 0:50:12Godin, La Condamine and Bouguer take their seats, up here.
0:50:12 > 0:50:15And, as they look down, they can hardly believe their eyes,
0:50:15 > 0:50:18because here's Seniergue, the expedition's surgeon,
0:50:18 > 0:50:22and on his arm he's got Manuela - a beautiful local girl -
0:50:22 > 0:50:25and he makes a big fuss of bringing her in.
0:50:35 > 0:50:37The crowd couldn't believe their eyes.
0:50:39 > 0:50:43And they were angry, because here's a French guy with a local girl,
0:50:43 > 0:50:46who they knew was previously engaged to a local guy.
0:50:46 > 0:50:50So, not only were they angry at Seniergue, but the whole French expedition.
0:50:55 > 0:50:58Immediately, Seniergue just plays to the crowd.
0:51:01 > 0:51:05And these three up here can just feel the crowd getting angry.
0:51:12 > 0:51:18Because Seniergue had flaunted this relationship, it just enraged the crowd.
0:51:18 > 0:51:21And the crowd turned into an angry mob.
0:51:24 > 0:51:28They surged forward around Seniergue, and began to stone him.
0:51:31 > 0:51:35And our three guys - La Condamine, Bouguer and Godin -
0:51:35 > 0:51:39they almost responded, they almost went to help him, just like a proper team.
0:51:39 > 0:51:43But they didn't. They saved their own skins instead.
0:51:43 > 0:51:47But as they fled the bull ring, the crowd followed them.
0:51:50 > 0:51:54Soon, the mob were hard on their heels, brandishing knives and swords.
0:51:59 > 0:52:04Now, on the brink of completing their mission, they were in fear for their lives.
0:52:26 > 0:52:30CRIES OF PAIN
0:52:31 > 0:52:35'As Bouguer lay bleeding, it looked as if the expedition was over.'
0:52:37 > 0:52:40Luckily, Bouguer's wound wasn't fatal,
0:52:40 > 0:52:44but Seniergue had been stoned and stabbed many times.
0:52:44 > 0:52:50And he endured a long and painful death, lasting four days.
0:52:53 > 0:53:01'It was now October 1739, and the scientists had been away from France for over four years.
0:53:01 > 0:53:08'But despite the hostile atmosphere in Cuenca, the team still refused to abandon their scientific quest,
0:53:08 > 0:53:11'and they remained here to take their star sightings.
0:53:16 > 0:53:22'Larrie Ferreiro took me to the very church where they did this final stage of their measurements.'
0:53:22 > 0:53:25So why would they have come here to this church?
0:53:25 > 0:53:28They used it as an observatory for some of their sightings.
0:53:28 > 0:53:32If I was gonna make star sightings, I'd be outside using me sextant.
0:53:32 > 0:53:36The sextant is what we would use today, but it really wasn't perfected at that time.
0:53:36 > 0:53:40Instead, they used an instrument known as a zenith sector,
0:53:40 > 0:53:44which resembled this drain pipe that I happen to have here.
0:53:44 > 0:53:48OK, how does it work? Let me show you how it works.
0:53:48 > 0:53:50Have a lie down. All right.
0:53:50 > 0:53:54OK. Tell me what you see. Well, a small patch of ceiling,
0:53:54 > 0:53:58but I presume they would be seeing a small patch of the sky.
0:53:58 > 0:54:02And that's exactly what they'd be looking for - a small patch of sky vertically above them.
0:54:02 > 0:54:07They would wait for a particular star to cross through that patch
0:54:07 > 0:54:12and determine when it was right above them. That way, they could discover their latitude.
0:54:12 > 0:54:15Now, the next step was probably the hardest.
0:54:15 > 0:54:18They had to do this at each end of the base line.
0:54:18 > 0:54:21Bouguer went north and La Condamine stayed here in the south.
0:54:21 > 0:54:25Each one had to make the same set of observations on the same star
0:54:25 > 0:54:29on the same night to get the arc of latitude they required.
0:54:31 > 0:54:34'This would tell them how many degrees of latitude
0:54:34 > 0:54:37'their line down through the Andes corresponded to.'
0:54:38 > 0:54:43'And from that, they could calculate the length of a single degree of latitude.'
0:54:48 > 0:54:51How long did all these measurements take?
0:54:51 > 0:54:55Well, each set of observations could take weeks or even months to make.
0:54:55 > 0:54:58Ultimately, it took them years - three years, in fact.
0:54:58 > 0:55:01So it took them three years to do what I could do
0:55:01 > 0:55:04or we could do right now with my GPS in a few days?
0:55:04 > 0:55:06That's right. Or even a few seconds.
0:55:08 > 0:55:12But after these three long years, the sightings were complete.
0:55:19 > 0:55:25The trip, which was supposed to take three years, had now taken eight,
0:55:25 > 0:55:28and cost the lives of two men.
0:55:31 > 0:55:35They had endured stifling rainforests and freezing conditions,
0:55:35 > 0:55:38incessant arguing and murder attempts.
0:55:41 > 0:55:43All in the pursuit of science.
0:55:43 > 0:55:46All to find just one number.
0:55:50 > 0:55:53Finally, they had a result.
0:55:53 > 0:55:57It was just one number, but it was an incredibly important number.
0:55:57 > 0:56:03110.61 kilometres, which was the length of one degree of latitude at the equator.
0:56:03 > 0:56:07And crucially, compared to one degree of latitude in France,
0:56:07 > 0:56:11it was shorter, which meant that the Earth was kind of grapefruit-shaped -
0:56:11 > 0:56:14fat in the middle and flatter on the poles -
0:56:14 > 0:56:18which was exactly as Sir Isaac Newton had predicted.
0:56:18 > 0:56:22All that hard work and tenacity and attention to detail
0:56:22 > 0:56:26from Godin, La Condamine and Bouguer had paid off.
0:56:31 > 0:56:37The result was a revelation that would change navigation and map-making forever.
0:56:37 > 0:56:44But perhaps their greatest legacy was from the chance discoveries they made along the way.
0:56:52 > 0:56:54They kick-started the rubber industry,
0:56:54 > 0:57:01giving us many things we take for granted today, like water-proofing and car tyres.
0:57:03 > 0:57:09They gave us quinine, a chemical that has saved millions of people from malaria.
0:57:10 > 0:57:14And they gave us the basis of the standardised metric system.
0:57:14 > 0:57:19What is a metre? What does a kilo of apples weigh?
0:57:19 > 0:57:25What's more, they provided support for the theories of Isaac Newton,
0:57:25 > 0:57:30whose work would change the course of science entirely.
0:57:33 > 0:57:37But most of all, this seemingly shambolic group of men
0:57:37 > 0:57:42had revealed one of the most fundamental of all things -
0:57:42 > 0:57:45the true shape of our planet.
0:57:56 > 0:58:00'Yet, for the French team, there were no celebrations.
0:58:00 > 0:58:06'At the end of their epic mission, there was only enough money left to send one of them home.'
0:58:06 > 0:58:09Bonne chance. A Paris! Oui.
0:58:09 > 0:58:14'Bouguer jumped at the chance to return to a hero's welcome.'
0:58:17 > 0:58:20Bonne chance. Au revoir.
0:58:20 > 0:58:25'La Condamine headed into the Amazon in search of more adventures.
0:58:26 > 0:58:31'While Godin, bitter and isolated, never returned to Europe.'
0:58:33 > 0:58:36It was a modest and subdued end
0:58:36 > 0:58:40for these most unlikely heroes of science.
0:58:44 > 0:58:47Subtitles by Red Bee Media Ltd - 2006
0:58:47 > 0:58:50E-mail: subtitling@bbc.co.uk
0:59:20 > 0:59:22Utopia - the better place.
0:59:22 > 0:59:24Somewhere between fiction and reality.
0:59:24 > 0:59:26The idea has exerted
0:59:26 > 0:59:29such a hold over us, but why?
0:59:30 > 0:59:32Join me, Richard Clay,
0:59:32 > 0:59:35as I venture across hundreds of years of art,
0:59:35 > 0:59:36literature and philosophy.