Venus. The second planet from the Sun. Brightest star in Earth’s night sky.

In 1627, the German astronomer Johannes Kepler realised it was possible to predict the Transit of Venus; that rare moment when, observing from Earth, Venus would appear to pass across the face of the Sun. And that was important, because if you knew how long that took, you could determine the average distance from the Earth to the Sun. If you had that, you could measure the entire solar system.

The next visible transit of Venus, Kepler predicted, would be in 1631, but just one year before that, Kepler died. He did not get to see the Transit—and neither did anybody else, because his notes were not very helpful.

But all was not lost. Another astronomer, Jeremiah Horrocks, believed that as a rule, Transits of Venus occurred in pairs, eight years apart. So, the next one should be in 1639. He was right, and in that year, he recorded the fabled Transit and thus determined the distance between the Earth and the Sun. Inaccurately, as it turned out. Perhaps if he’d had another chance, he would have been able to refine his first calculations. But Horrocks had also discovered that after the transits in 1631 and 1639, there wouldn’t be another for over a hundred years. Transits came in pairs, but only once in a century. Two close chances in a lifetime.

In 1716, the British astronomer Edmond Halley made a plan to observe the next Transits in 1761 and 1769, which he himself would not live to see. He called for excellent astronomers from a coalition of enlightened nations to be stationed at key points around the globe, where they could gather as much data as possible on the transit, simultaneously. It would be a huge undertaking, requiring the co-operation of European nations who were normally at constant war with one another. But everyone recognised that the pair of transits coming up would be, quite literally, a once in a lifetime opportunity to unlock the secrets of the solar system. The next ones wouldn’t be until 1874 and 1882. Who was going to observe those, Jack the Ripper?

‘No way!’ the nations of Europe cried out as one. ‘We’ll do it!’

‘Okay,’ said Edmond Halley. ‘I’m going to die pretty soon, but I trust you.’

Halley died in 1742, aged 85. He’d laid the groundwork for the greatest global astronomical undertaking in the history of mankind. It was a shame he wouldn’t be around to see it, but he had to be content that, in his lifetime, lots of other great stuff had happened. He’d seen a comet. He’d learned Arabic. He went to Stonehenge. Isaac Newton came up with gravity. Ballet and Freemasonry got started. Someone created the world’s first robot and taught it to play the flute. Paradise Lost was published. Blackbeard was alive. Humankind successfully hunted the dodo to extinction. In Sweden, they had a 30th of February for an entire year. It was quite a time to be alive.

But maybe it was good that Edmond Halley’s life ended there, because if he had lived long enough to see what happened next, he would have been absolutely furious.

You’re listening to Something True – stories from the footnotes of history. Written by Duncan Fyfe and read by Alex Corbett Ashby. This week’s episode: Odyssée.

It was time. March, 1760. To prepare for the Transit of Venus on June 6th, 1761, 122 astronomers left their homes and headed for 62 observation stations around the world. Charles Mason and Jeremiah Dixon went to the Cape of Good Hope. Jean-Baptiste Chappe went to Siberia. And bound for Pondicherry, India, was Guillaume Le Gentil.

Thirty-five years old, Le Gentil had thrown away a career in theology to study the stars in Paris. He was good: He’d discovered clusters, clouds and dwarf galaxies—but all that was no better than bird watching, compared to the Transit of Venus. He was thrilled to get the assignment. He packed up his telescope, bid his family in Paris adieu and boarded an East India Company ship travelling to Isle de France – now Mauritius – a recently acquired French colony, where he would switch ships for India.

‘There’s nothing like a sea voyage!’ Le Gentil marvelled from the prow. ‘The adventure... the salt air... the big boat... I love it all!’

But there was one little setback. When Le Gentil arrived at Isle de France and tried to board a ship bound for Pondicherry, India, he learned that in the four months he’d been at sea, England and France had gone to war... in Pondicherry, India. Ships just weren’t going there. So, he’d have to cool his heels on the island, for the summer, at least. It wasn’t a bad way to spend the time—summer in Mauritius? Dolphin spotting, museums, a dodo graveyard, excursions to beaches and waterfalls... but the only excursion he'd be making would be to the toilet, at the behest of that wicked master called dysentery. Le Gentil was agitated: How could he go on a two-month sea voyage when he couldn’t even leave the potty?

It was now February 1761, and with the transit four months away and in a different country, it was beyond time for Le Gentil to make a move. Finally, his luck changed. A French frigate made a stop in port, carrying news for the troops fighting in Pondicherry. Pondicherry! Perfect! ‘Au revoir, our colonial possession!’ Le Gentil waved from the ship, as a powerful wind then hurled it in completely the wrong direction.

Nevertheless, they made it to India, although a little delayed, on May 24th. But on the wrong coast, and it got worse. ‘You know how we’re doing a war?’ they heard from the French soldiers. ‘Well, the English are pretty good at it, and they’ve seized Pondicherry, so that’s a no-go. Actually, they seized it months ago. Before you left Isle de France, in fact. Did you not know that? That is so funny! You could have just stayed. Anyway, you should leave immediately.’

‘Oh, come on,’ Le Gentil pleaded. ‘I’ve been travelling for a year, there’s only two weeks until the Transit, and I’m finally so, so close! I even have a letter of introduction from King Louis that explicitly says, “I know we’re at war, but please, let this man do his important scientific work!”’

The crew of the ship weren’t having it. ‘Sorry. That’s the end of the beans, my bro.’ And it was back to Isle de France.

Which meant that Guillaume Le Gentil was stuck on a boat in the middle of the Indian Ocean on June 6th, 1761. The day of...

THE TRANSIT!

‘I can see it! I can sort of see it!’ Guillaume yelled, running up and down the deck of the ship with a telescope and a notepad. ‘Oh look, look, look, there it goes! If I shout out numbers can someone remember them?!’ But it was hopeless. And soon, that brightest star of the Earth’s night sky was gone.

It turned out that nobody had got a really good look at the Transit. An uncommon phenomenon called the black drop effect had made it difficult to accurately determine exactly when Venus appeared to touch the edge of the sun. Everybody resolved to do better for their next shot at the prize, in eight years’ time.

‘You know what,’ Le Gentil thought, back on Isle de France, ‘why don’t I just stay here until the next Transit? I’m far closer to it now than I would be back in Paris. I do love the big boats, but things can go wrong on a voyage. This next Transit is the last shot I’ll ever have at this, and I don’t want to leave anything to chance!’ He sought permission from the Academy of Sciences to remain in the Indian Ocean, collecting scientific data on the flora and fauna around Isle de France and Madagascar. The Academy gave him the thumbs up. ‘Marvellous! Simply marvellous!’ Le Gentil cried. In celebration he ate some local beef, which gave him a stroke.

Five years passed, during which Le Gentil busied himself with local observations. In this time he’d realised that a better place to view the second transit would not be in Pondicherry, but Manila, in the Philippines. So, he booked passage and arrived in Manila, then a Spanish colony, in August 1766, leaving him almost three years in which to prepare. But... he didn’t love it in Manila. The Spanish governor was very rude. ‘So, you’re French, are you?’ he bellowed. ‘I despise the French! Now, stay still while I read to you from my favourite book, “101 French Jokes to Make You Say Sacré Bleu”!’

‘Sir, please, treat me with some dignity! I am an important astronomer on an international mission, following in the footsteps of Halley and Kepler!’

‘An astronomer? To me, you look more like the theory of evolution—because I’ve never heard of you! All the astronomers I know have a letter of recommendation from their King saying I should treat them nicely—where’s yours?’

Le Gentil’s letter from the King of France had been for Pondicherry, not Manila. He had written away for a new one before leaving Isle de France, but...

‘I... don’t have it yet! It takes time!’

Le Gentil didn't get his letter from the King until the next year. Smugly, he presented the royal missive to the governor, who inspected it closely. ‘Hmm... this says you wrote to the King over a year ago... that’s not nearly enough time to write to France and get a response! Did you really expect me to fall for this pathetic forgery? Sir, as you know full well, I already have 101 side-splitting French jokes—I certainly have no need of another one!’

At about this time, Le Gentil received more useful correspondence, with news of his astronomer friend, Alexandre Pingre. Pingre had been in Madagascar for the 1761 transit and was now stationed in Haiti for the second. He thought that Le Gentil’s calculations were wrong; Manila was not the place to observe the transit. To get the best look at it, he said, Le Gentil should head for Pondicherry, India.

‘Pondicherry!’ gasped Le Gentil. ‘But then, all is lost! Didn’t the English seize it?’

‘Oh really, Guillaume, where have you been? It’s French again, baby!’

Pondicherry was far away, but Le Gentil would have taken any excuse to leave Manila, and departed on February 1768. Now things were really cooking. In March 1768, with more than a year to go before the transit, Le Gentil arrived in Pondicherry, which was indeed back in French hands. The French governor welcomed him with an extravagant reception. ‘I’m all about your mission, bro; stars? Fucking wicked, mate. You just pick out where you want an observatory and I’ll get these guys to build you one. Now, just sit back, relax, listen to whatever passes for music in the eighteenth century, and munch down on some moist mutton, my dude!’

In the following months, Le Gentil was all set up. One year remained. His last year. His last chance.

The weather in Pondicherry hadn’t been great. But from the start of May, 1769, with mere weeks remaining, the sky was beautiful and clear. So perfectly clear it was as though Indra, the Indian king of the gods, was extending a celestial finger to Guillaume Le Gentil and whispering, ‘I love you, and I want this for you, my special boy.’

June 4th, 1769. The day of...

THE TRANSIT!

Le Gentil leapt out of bed at two a.m. and rushed to his telescope. ‘Here we go! Come on Venus, my friend, here we go!’

There were clouds blocking the sun.

Okay. Okay. A couple of clouds weren’t the end of the world. And the Transit of Venus lasted hours. In fact, he had almost five hours before Venus disappeared off the face of the sun completely. Who ever heard of clouds that stick around for five hours?!

No. No. He paced. It would be okay. He just had to be patient. He’d been patient so far—he’d left France nine years ago! He could be patient for five more hours.

So he waited, and checked back in with the telescope—warily—dreading what he might see. Through the lens, he saw... even more clouds. Ridiculous. Fucking ridiculous. He needed a miracle. Something, something had to happen!

Five a.m. Two hours before the end of the transit. A wind picked up.

A wind! A wind! Tribal enemy of the cloud! This was it! This was his salvation! ‘Go, wind! Get those clouds out of the way! Go, wind! Go, wind!’ As if it were fuelled by his prayers of desperation, the wind blew harder, and harder. Yes. Yes!

He flew to the eyepiece of his telescope... and saw... A SECOND LAYER OF CLOUDS BLOW IN FRONT OF THE SUN. AND STAY THERE.

Then, it rained on him.

And Venus was gone.

[PROTRACTED EXISTENTIAL MOAN OF ANGUISH]

He took a deep breath. There was only one thing he could do. He crawled back into bed and stayed there for two weeks. What he didn’t know, and this was probably a good thing, was that back in Manila, it had been clear skies all the way.

Guillaume roused himself later in the month, but in September he got sick, and went back to bed. Dysentery. Dysentery again. He had been planning to sail with a French ship that was headed to Isle de France, but he had to let it go: How could he go on a two-month sea voyage when he couldn’t even leave the potty?

December. More dysentery.

The following March, a ship finally arrived that was headed for Isle de France. Both the seas and his bottom were clear. Le Gentil packed up his stuff and got on board. In April, the ship arrived at the island, and planned to keep going to France, but Le Gentil got sick again, and had to get off. He remained stuck on Isle de France, like the days of yore.

Months passed. People asked him: ‘Hey, why not occupy yourself, my dude? Go to Tahiti. Make some discoveries there!’ But he had had it.

‘No... please. I just want to go home.’

Finally, in July, an East India Company ship arrived. ‘Ahoy there!’ cried the captain. ‘I hear there’s a boy on this island who’s been waiting for a big boat!’

‘Yes, it’s me. I’m that boy...’

At long last, Le Gentil was going home.

Almost. A month into the voyage, the ship was attacked by hurricane. Le Gentil looked on in horror as the masts broke, the sails came down, and leaks sprang all over the hull. All of Le Gentil’s stuff—his ten years of notes and observations—went into the sea. But the worst thing, the absolute worst thing, was that when the storm had cleared, the captain decided they had no choice but to go back to Isle de France.

It was seven months before another suitable ship arrived at the island. A Spanish warship, headed to Cadiz. Le Gentil jumped at the opportunity.

Like the last, this journey encountered bad weather too. Tempest upon tempest trammelled the vessel as it rounded the Cape of Good Hope, but the captain did not give up. ‘Faster’, he cried, ‘faster’! The ship broke through and passed the cape. From there it was clear sailing to Cadiz.

Except...

As the Spanish vessel continued on its journey, it met an English ship.

‘I don’t want to alarm you,’ the captain told Le Gentil, ‘but I think Spain is actually at war with the English.’

‘At war?! Over what!’

‘The Falklands, I think?’

‘The Falklands? Are you sure? Well, I mean... are you going to fight them?’

‘I mean... I think we have to?’

The two ships drew to a standstill opposite one another.

‘Erm, hi,’ called out the English captain. ‘How are you?’

‘Um, good,’ replied the Spanish captain. ‘so, you’re my prisoner, okay? Because we’re at war, Spain and England, that’s what I heard.’

‘Um... I don’t think so.’

‘Really?’

‘Yeah, oh, are you talking about the Falklands?’

‘Yeah.’

‘Okay, yeah, I think they sorted that one out, mate, we’re not at war anymore.’

‘Wait... are you sure? What year is this?’

The English captain produced a recent copy of the London Gazette, which backed up his claim: England and Spain were not at war.

So, they had a big boat party. The Spanish had wine, and the English had potatoes. And Le Gentil was not so depressed that he couldn’t point out that the English potatoes were inferior to the French variety.

In August, the ship landed at Cadiz, and Le Gentil disembarked, to travel over land back to France. Where he finally concluded his own transit, on 8 October 1771—11 years, 6 months and 13 days after his departure.

‘Wait, wait, wait,’ everyone said when they saw him. ‘Guillaume Le Gentil? Aren’t you dead?’

‘No, I’m clearly not dead.’

‘Well, everyone thinks you’re dead, so.’

It was true. At some point in the last 11 years, he’d been declared legally dead, and his estate divided up amongst his relatives. He returned to the Academy of Sciences.

‘I’m sorry,’ he said. ‘I didn’t get a good view of the transit.’

‘Oh—were you still doing that?’

‘Yeah. Yeah, well I was trying.’

‘Oh, well, never mind. By the way, I see here that your membership has expired, and this area is for scientists only, so... get out?’

Guillaume Le Gentil never really saw a Transit of Venus and knew that he never would. For those of us listening in 2019, we find ourselves in the same position. The next transits of Venus will be in 2117 and 2125., and none of us are going to live that long, even if we try really hard.

Unlike Guillaume Le Gentil, however, we can watch the Transit of Venus whenever we want. The 2012 Transit is on YouTube. And we know the distance between the Earth and the Sun. It’s 150 million kilometres. That information is available to us instantaneously, and Guillaume Le Gentil would have killed to know that.

But: Could we have reached this point without the diligence and daring of Guillaume Le Gentil? Well, yes. And we did.

But: despite this, Guillaume Le Gentil lived happily ever after. As he walked down the streets of Paris, people stopped and stared, and popped out of their windows in disbelief. ‘Guillaume Le Gentil? Is that really you? Are you really alive?’

‘Yes!’ he cried. ‘It is me, Guillaume Le Gentil, and I am back! I went away to observe the Transits of Venus and I failed spectacularly. I didn’t see them! I shamed the memory of Edmond Halley! I spent 30,000 days taking notes on the creatures and cultures of the islands of the Indian ocean, and I lost all that work in a hurricane!

‘Let there be no question about it: I have been gone for a very very long time and I have absolutely nothing to show for it! But I am alive! I am... alive! I AM ALIVE!’

And, he was. For a while.

That was Something True, a podcast on the Idle Thumbs network, written by Duncan Fyfe and read by Alex Corbett Ashby. Music credits can be found in the description and on our website at somethingtrue.net where you’ll also find a full transcript of this story. Thank you so much for listening to this second series of Something True. If you would like to see us return for more episodes please do take a moment to leave us a review, share the podcast with your loved ones, or just let us know on Facebook or Twitter @atruepodcast, but for now, to each and every one of you: au revoir.