Where the F*** Are We?

ROMAN MARS: This is 99% Invisible. I’m Roman Mars. 

There’s an archipelago in the far west of the UK. And I mean far west. Like, once you think you’re in the west, like around Cornwall, keep going. And then take a ferry another three hours west, and you’ll find yourself in a collection of islands called the Isles of Scilly. 

KELLY PRIME: That’s silly spelled S-C-I-L-L Y, not silly ha ha. 

ROMAN MARS: That’s 99PI producer Kelly Prime. 

KELLY PRIME: In fact, Silly is not ha ha at all. It’s a place that’s hard to wrap your mind around. The islands sit in the warm waters of the Gulf Stream so you’ll find tropical plants like giant palms and birds of paradise all blooming up against the backdrop of the rugged North Atlantic. 

ROMAN MARS: It’s also, historically, one of the deadliest places in the UK to travel by sea. 

KELLY PRIME: These islands are plopped down in churning waters with jagged rocks rising all around like the jaws of some sort of mythical sea creature. In this past October, I found myself on a little boat called the Buccaneer right in the middle of it. 

TODD STEVENS: It’s crazy, man. It’s a crazy place. You know, we’ve got… There’s just rocks everywhere. As you’re going along, you don’t realize, we’re passing rocks under the water all the time. 

KELLY PRIME: The Buccaneer belongs to a scuba diver named Todd Stevens. Todd has been diving the shipwrecks around Scilly for over two decades. 

ROMAN MARS: If you’re into shipwrecks, it’s really hard not to find one here. At least 900 shipwrecks litter the coasts of Scilly–probably more. Sometimes ships will sink on top of other, older shipwrecks, so it’s difficult to say for sure. 

KELLY PRIME: Are there shipwrecks below us right now? 

TODD STEVENS: Yeah, yeah, we’ve passed quite a few. If you’d have been asking me that as we were just coming along St Mary’s shoreline, there’s at least half a dozen along there. 

KELLY PRIME: Oh my God. Are there life jackets on this boat? 

KELLY PRIME: We were specifically looking for the remains of one particular disaster, where not one but four ships were lost on the same night: The HMS Association, Romney, Eagle, and Firebrand. 

TODD STEVENS: We’re just coming up on the Firebrand now. So we’re right over it now. The wreck lays just across here and her bowels are up that way because her anchors are up that end and then she lays across here. 

ROMAN MARS: The wrecks happened on October 22nd, 1707. It was quite literally a dark and stormy night. And there was a fleet of British naval ships bravely led by an admiral named Cloudesley Shovell. 

KELLY PRIME: Shovell and his fleet had just fought a battle with the French. They were headed back and, according to their maps, they were about to pass safely into the English Channel. But in reality, they actually were 200 miles off course, exactly where you really do not want to be–smack in the middle of the Isles of Scilly. 

ROMAN MARS: The HMS Association crashed into one of the many jagged rocks just beneath the surface of the water. The death toll was somewhere between 1,400 and 2,000. It was, at the time, the deadliest shipwreck in British history. 

KELLY PRIME: But the important thing about this shipwreck–why it’s still remembered today–isn’t just the scale of the disaster. It’s also why it happened and how it could have been avoided because the navigators of the fleet were missing a vital piece of information. 

KELLY PRIME: And do we know why they thought they were that far?

TODD STEVENS: Yeah. They didn’t know their longitude. So, they were guessing.

ROMAN MARS: The reason this fleet was so dangerously off course was because they didn’t know their longitude, their east-west coordinates. 

KELLY PRIME: And this wasn’t because they lost their map or their navigator was killed by pirates or they were just really bad at their jobs. They didn’t know their longitude because, at that point, no one knew how to calculate longitude at sea. 

ROMAN MARS: It was a problem that had plagued navigators and scientists for centuries. The greatest minds of Europe–Isaac Newton, Galileo Galilei, and the Haley’s Comet guy–they all tried and failed to find a way to calculate longitude at sea. Most people thought it simply wasn’t possible. 

KELLY PRIME: That is, until the 18th century, when the disaster in Scilly helped inspire Britain to action. 

ROMAN MARS: What follows is a tale of imperial greed, a lucrative contest, and an obsessive underdog who became his own worst enemy. 

KELLY PRIME: But before we tell you about all that, we need to explain what longitude actually is, which is a lot harder than it sounds. 

ALEXI BAKER: Basically, longitude is the east-west coordinate. So if you think of the Earth as an orange and you peel 24 vertical pieces of that orange, each peel represents 15 degrees of longitude away from the prime meridian. And that’s because longitude is counted off in the same direction as the Earth is rotating on its axis. So, you know… I think I’ll start over on this description. It’s gotten away from me. [LAUGHS]

KELLY PRIME: This is Alexi Baker, Manager of the History of Science and Technology Collection at the Peabody Museum. And see? I told you this was hard. 

ALEXI BAKER: Should I use the orange? Should I not use the orange? Okay.

ROMAN MARS: Maybe let’s give it a try without any citrus fruits. 

ALEXI BAKER: So longitude are the vertical lines on the globe and latitude are the horizontal lines. And when you move besides beyond vertical and horizontal lines, it does quickly get away from you. 

KELLY PRIME: I’m gonna try to do this as simply as possible. So latitude and longitude came about when some Greek guy from a very long time ago decided to throw some lines on the globe, the idea being that, if we put lines on a map, they’ll form a grid. And then people can use that grid to navigate the world with more precision. 

ROMAN MARS: This grid is what gives us GPS coordinates. For example, the Pandora building in beautiful uptown Oakland, California–that’s around 37.810 North, 122.267 South. 

KELLY PRIME: The trouble with this imaginary grid system is that it’s imaginary. These values were great for understanding the world from a distance–for looking at a map from the comfort of your own home. But if you actually wanted to use the system to navigate, like if you were out in the middle of the ocean, you needed to be able to calculate your latitude and longitude in real time. 

ROMAN MARS: Which was annoying. Before the age of GPS, the best navigational tool available was the sky. The sun, the moon, and other celestial bodies were your reference points, no matter where you were in the world. 

KELLY PRIME: That made latitude pretty simple. It’s just based on your distance north or south of the equator–easy enough to figure out by looking at the sky. 

ALEXI BAKER: Latitude you can determine by just measuring the height of the sun or the pole star above the horizon you see. 

KELLY PRIME: If you can see the North Star and it’s 10 degrees above the horizon, you’re at 10 degrees latitude. Using the sun takes a little more calculation, but it’s still very doable. 

ROMAN MARS: Getting Longitude, on the other hand, is a completely different story. 

ALEXI BAKER: Longitude is a lot harder to find than latitude. 

ROMAN MARS: The reason calculating longitude is so much harder is largely down to the fact that the Earth doesn’t stay still, it spins. 

KELLY PRIME: The Earth rotates west to east, which means even while the north-south values, like the poles, equator, and lines of latitude, all stay fixed, the sides of the Earth–the east-west values–are in constant motion. 

ROMAN MARS: Calculating longitude is like trying to keep track of all the horses on a carousel. No matter how hard you try, they’ll just keep spinning out of sight. 

KELLY PRIME: What all this means, in practice, is that you can’t get longitude just by looking at the sky. None of those useful celestial bodies will hold still. And so for many, many years, longitude was just garbage as a real world value. 

ROMAN MARS: Sailors did manage to get around without knowing their longitude, but not very well. They were forced to make do with depressingly bad methods. 

KELLY PRIME: One such depressingly bad method was called “sailing the parallels,” where ships could find one line of latitude and just stick to it until it was time to basically turn north or south off the highway. This was a really popular approach, enough so that everyone started sailing along the same lines. 

ROMAN MARS: Which might’ve been a great idea if it weren’t for the fact that pirates also knew these routes. And so they could just sit around, doing basically no work, and pick off whatever ships they wanted. 

KELLY PRIME: Another less bad way of estimating longitude was called “dead reckoning,” a way of measuring speed and direction. How it worked is that you’d tie a series of knots in a rope and then throw that rope behind you in the water. How quickly the knots fed out would tell you how fast you were going. 

ROMAN MARS: This is actually where we get knots as a unit of speed. One knot equals one nautical mile per hour. If you remember nothing else, remember that. 

KELLY PRIME: Having a general sense of speed could tell you how far you’d gone east or west. But dead reckoning was notoriously inaccurate, especially on long journeys where even small errors could accumulate. 

ROMAN MARS: For centuries, everyone from seamen to astronomers struggled to figure out what became known as the problem of longitude. And so much time passed without a solution that people put longitude in the same bucket as finding the philosopher’s stone or turning lead into gold. Basically, you’d go mad before you’d ever figure it out. 

DAVA SOBEL: The idea of discovering a way to determine longitude at sea, at that time, was tantamount to attempting mission: impossible. 

KELLY PRIME: This is Dava Sobel, who wrote the best-selling book Longitude.

DAVA SOBEL: People just didn’t think it could be done. It was one of those things you would talk about, like the secret of perpetual motion, but you didn’t really expect it to happen. 

ROMAN MARS: Still, that didn’t stop the big colonial powers of Europe from trying for longitude. There was just too much riding on a solution. 

DAVA SOBEL: The stakes were high–life and death.

KELLY PRIME: Having accurate coordinates at sea could mean the difference between making a swift, safe journey and, say, veering dangerously off course, hitting a rock, and drowning with a guy named Cloudesley. 

ROMAN MARS: In other words, it was just a lot safer to know where you were going. 

KELLY PRIME: But the search for longitude wasn’t only about safety. For Great Britain, it was also very clearly a matter of empire. 

ALEXI BAKER: It was really important to that vision of Britain sort of taking over the world, both commercially and literally. 

KELLY PRIME: In the early 18th century, Britain had colonized parts of North America and the Caribbean and they were actively growing the transatlantic slave trade. Having longitude would mean shorter, more predictable journeys. In other words, they’d be able to do more horrible things more quickly. 

ROMAN MARS: Global powers of the time knew that there was an ill-gotten fortune to be made if your kingdom’s ships were the fastest, most efficient, and safest ones on the ocean. 

DAVA SOBEL: So even though everybody considered it mission: impossible, still there was a sense of “wouldn’t it be great if we could do this?”

KELLY PRIME: So, with global domination on the line, Parliament passed the Longitude Act of 1714. 

DAVA SOBEL: Which offered a fantastic monetary prize to solve this problem of finding the longitude at sea. 

ROMAN MARS: The Longitude Act of 1714 dangled a massive prize in front of anyone who could come up with a workable solution. Parliament was trying to motivate the great scientific minds of the time, for the love of God, to finally figure out where the [BLEEP] they were. 

KELLY PRIME: The rules of the act were this. If your idea passed muster with a board of qualified judges, you’d be sent on a trial journey to a place of known longitude, in this case, Britain’s colonies in the Caribbean, then known as the West Indies. And there were different prizes depending on how close your ship got to the bullseye. 

ROMAN MARS: If you pulled into Harbor with the greatest level of accuracy, just 30 nautical miles or half a degree of longitude, you’d get the highest prize. 

DAVA SOBEL: The prize was 20,000 pounds. So you can imagine. This was really worth extending yourself to try to win this. 

ROMAN MARS: With the modern equivalent of around 3 million bucks on the line, all sorts of people came out of the woodwork with wacky solutions involving, among other things, cannons, dogs, and magic powder. 

KELLY PRIME: Most of those proposed ideas weren’t given any real consideration. For one, they were stupid. But two, it was believed that if someone could find a solution to the longitude problem, that solution would probably come out of the field of astronomy. 

DAVA SOBEL: You got your latitude from the sky, so why wouldn’t you get your longitude? I mean, it just seemed to make sense. 

ROMAN MARS: In the world of navigation, astronomy reigned supreme. Astronomers were men of science. And over the many, many years, they had been inching closer to a solution. But for all their high towers and stargazing, no one had managed to bring the issue of longitude within reach. 

KELLY PRIME: That is, until an unexpected dark horse entered the race. 

DAVA SOBEL: Astronomy had an entire international network of people working on it. And then this guy from Yorkshire came along with his clock. 

KELLY PRIME: John Harrison was not an astronomer. He was a self-taught clockmaker and the son of a carpenter. 

DAVA SOBEL: He lived in an unglamorous section of England, he seems to have been entirely self-educated, and he achieved things in precision timekeeping that were highly unusual for the time. 

ROMAN MARS: Historical records of his early life are scarce, but we know that he was born in 1693 and generally described as a sort of single-minded eccentric guy who was a genius when it came to clocks. 

EMILY ACKERMANS: Harrison was very determined to win this reward. He wanted that top reward, 20,000 pounds. 

KELLY PRIME: This is Emily Ackermans at the Royal Observatory in Greenwich. Her title is actually the Curator of Time, which sounds like the name of a Doctor Who episode but is actually her job. I met Emily in the observatory, surrounded by mysterious brass instruments and all the people coming to look at them. 

EMILY ACKERMANS: He wasn’t a member of the Clockmakers Guild. He didn’t follow a traditional apprentice path, so he did design very unique clocks. 

KELLY PRIME: Harrison, who worked alongside his brother, James, took an outsider’s approach in his clockmaking. He invented new features like the gridiron pendulum and grasshopper escapement. These terms might not mean anything to you unless you study clocks, but trust me, the horology crowd is probably freaking out right now.

ROMAN MARS: Harrison’s timekeepers were some of the best, most accurate clocks in the world, which made him particularly well-suited to finally solving the longitude problem. 

KELLY PRIME: That’s because a solution to the problem of longitude at sea actually already existed, at least theoretically. 

DAVA SOBEL: What time is it in two places at once? And that will nail your position. 

ROMAN MARS: The whole scientific community had known for a long time that it was hypothetically possible to calculate longitude using time differences. You just needed to know your own local time and the time back at your home port. 

KELLY PRIME: The best way I’ve found to imagine this is to think about our modern concept of time zones. How many hours away something is can tell you roughly how far away that place is. So I’m in New York and Roman’s in California. He’s three hours behind me. But Hawaii is five hours behind, which means Hawaii is farther away than California. So time can give a pretty good estimate of distance east and west. 

ROMAN MARS: And you can get even more precise than that. One hour equals 15 degrees of longitude. 

DAVA SOBEL: It’s one o’clock here. It’s 10 a.m. in California. Okay. So, we know that’s a three-hour difference. 45 degrees of longitude. And if you look on the map, I think you’ll see that’s about right. 

KELLY PRIME: So if you could get your local time using the sun overhead and you knew what time it was back home, you’d know the distance between those two places. You could calculate your longitude. 

ROMAN MARS: This might sound like a pretty simple solution to the problem of longitude at sea. Just set a clock before leaving and take it on board your ship. 

KELLY PRIME: But back in the 1700s, that wasn’t an option. Clock design at that point was just too unreliable. 

EMILY ACKERMANS: They’re so susceptible to inaccuracy. It’s incredible they work at all. No, I’m joking. [LAUGHING] When people say it runs like clockwork, I generally think, “Oh, not very well then.”

ROMAN MARS: During this era, all clocks were kind of crappy. But bring one of those crappy clocks on board a ship and it was useless. These were mostly pendulum clocks. And you can imagine how well a pendulum clock would work on a rocking ship. 

KELLY PRIME: There was also the issue of lubrication. The oils used in clockmaking had the tendency to get dirty and gunked up, especially in salty ocean air. And if you were traveling between warm and cold climates, the metal in your clock’s pendulum would expand and contract with temperature, making it gain or lose time. 

DAVA SOBEL: To actually get an exact position, your clock has to be extremely accurate. I mean within a fraction of a fraction of a second a day. 

ROMAN MARS: But where others saw problems, John Harrison saw an opportunity. 

He thought he could solve longitude not by looking at the stars, but by building a better clock. 

KELLY PRIME: Harrison came up with some really ingenious and creative solutions in order to make a seaworthy clock. To get around the need for traditional clock oil, he used wood from a type of tree called lignum vitae that actually exudes its own lubrication. 

ROMAN MARS: He also solved the problem of temperature by combining complementary metals–steel and brass–that expand at different rates and at different temperatures, which stopped the metal components from changing shape. 

EMILY ACKERMANS: So he’s already solved two of the three problems–the three main problems–that are facing portable clocks at sea. 

ROMAN MARS: To deal with the problem of keeping a pendulum clock running on a rocking ship, Harrison made a modified pendulum with two connected bar balances that compensate for each other’s motion. A clock with these balances could keep time even when tilted around. 

KELLY PRIME: Harrison worked for five years straight to solve these three design problems. And what he ended up with was a clock known as Harrison 1, today called H1. 

KELLY PRIME: What are we looking at right now?

EMILY ACKERMANS: Wow, okay. So what are we looking at? I think it’s a very strange contraption. It doesn’t really look like a clock, which is why it’s so unique. 

KELLY PRIME: I have to say it looks extremely steampunk. Like, it could be in the Will Smith vehicle, Wild Wild West. 

KELLY PRIME: Emily showed me Harrison’s Sea Clock, which is on display at the Royal Observatory in Greenwich. What I looked at with Emily was actually the inner workings of the clock because, sometime over the years, the wooden case around it disappeared. The clock is made of gleaming brass with four small dials arranged on its face and an intricate system of tiny gears, springs, and bars behind that. It weighs a hefty 75 pounds. 

KELLY PRIME: It’s about the size of… What would you say? 

EMILY ACKERMANS: I always say you might get away with it as cabin luggage. 

KELLY PRIME: You could, yeah, maybe. 

EMILY ACKERMANS: Not with some airlines. But with a standard airline, you might away carrying it–

KELLY PRIME: Like a fancy international. 

EMILY ACKERMANS: Yeah. 

ROMAN MARS: After Harrison finished H1 in 1735, he got in front of England’s premier research institute, the Royal Society. This was a big moment for Harrison. A good review from the Society might put his invention in front the judges of the Longitude Act. 

KELLY PRIME: While the society was impressed with Harrison’s clock, they were also pretty hesitant to trust that his idea would work because why would they? 

DAVA SOBEL: You know, he’s just a guy. He’s doing all this in his home. 

KELLY PRIME: At this point, Harrison was just a clockmaker with no scientific background. So, having some skepticism about the whole thing, the Society decided to give H1 a preliminary test–a test test–not to the West Indies but to Lisbon. 

DAVA SOBEL: They agreed to put it on a boat, but they just sent it to Portugal, so not making the huge transatlantic voyage. 

ROMAN MARS: Harrison apparently got extremely seasick on the trip, like seasick enough that we are still talking about it 290 years later. But H1 performed marvelously. 

KELLY PRIME: In fact, when the HMS Orford was on its way back to Britain, the ship’s sailing master had them on course to pass a landmark just south of Dartmouth. But Harrison, using H1, sounded the alarm. He was able to pinpoint the ship location as 60 miles off course to the west. 

DAVA SOBEL: And then it turned out that he was right. And you can imagine how that affected the captain–everybody on the crew. 

ROMAN MARS: Harrison’s timekeeper was able to correct the ship’s longitude. 

DAVA SOBEL: “Wow, that was a magic trick! That was just… How did you do that?” And how he had done it was with that clock. And the whole crew of the ship he was on–they’re all ready to stand up for him. He’s not a crank. It’s not what everybody was expecting. But he’s not a crank! He’s got something! 

KELLY PRIME: So with the blessing of the Royal Society, all eight members of the official Board of Longitude assembled to hear about the successful Portugal trial and to judge Harrison’s sea clock. 

DAVA SOBEL: And Harrison is there with his clock. And what does he do? He says, “I don’t think it’s really good enough yet.”

KELLY PRIME: He didn’t want that big trial? 

DAVA SOBEL: No. Not yet. 

ROMAN MARS: Harrison could have asked for his H1 sea clock to go on a trial to the West Indies, and it’s likely the board would have given it to him. He could have tried for the prize, but he didn’t do that. What he did do was solidify his place as the absolute worst venture capitalist in the history of the world. 

KELLY PRIME: Harrison was so obsessed with getting his invention precisely, exactly, perfectly right that he showed up in a room full of people practically begging to give him a big pile of money and he pointed out the problems with his own design. He was apparently the only person in the room to say anything negative about his work. 

ROMAN MARS: And so, like the terrible entrepreneur he was, Harrison went back to the drawing board. 

DAVA SOBEL: So, H1… Maybe we’d call that beta. It proves the principle. A clock on a boat will work. It will tell you the time better than the ship’s navigator. That’s what you need. 

ROMAN MARS: What followed were over 20 years of working, and reworking, and re-reworking designs for various Harrison sea clocks. 

KELLY PRIME: All this time, John Harrison had been tinkering and tinkering, making prototypes with changes big and small to the same basic formula as H1. But then, in the mid-1750s, Harrison just happened to get a new pocket watch. 

ROMAN MARS: The watch was for his personal use, made by another clockmaker. At the time, watches were extremely unreliable, even more so than regular clocks, which, as we’ve established, were very crappy. 

DAVA SOBEL: You know, a gentleman might have a pocket watch, but it was just for vanity. It didn’t really keep good time. 

KELLY PRIME: But this watch, which used some of Harrison’s improvements, was extremely accurate. 

ROMAN MARS: Harrison looked down at his shiny new pocket watch and he realized that the key to a perfect sea clock was that he needed to think smaller. His other clocks were massive. And wouldn’t it be so much better to have something small and practical that a captain out at sea could keep on him at all times and carry in his hand? 

KELLY PRIME: It took him four years to complete his sea watch, H4. H4 was five inches in diameter, and it weighed just three pounds. So, compared to the carry-on luggage of H1, it could fit in a free personal item. 

ROMAN MARS: Except on Spirit Airlines, then it would probably cost 50 bucks. 

KELLY PRIME: Looking at H4 in the Royal Observatory, I was struck by just how different it looks from any of Harrison’s earlier sea clocks. 

KELLY PRIME: If the other ones look pretty steampunk, this looks just, like, so ornate and beautiful and delicate. Like, how would you describe that? There’s all this curving filigree–these blue iridescent dots… There’s, like, rubies and diamonds in there, right? 

EMILY ACKERMANS: Yes, so diamond palettes–we’re still not entirely sure how we made them. 

KELLY PRIME: I was going to say, are the gems just, like, gratuitous? Are they flared? Do they have a purpose? 

EMILY ACKERMANS: They have a purpose. They do, yes. And it’s all anti-friction or minimizing friction. 

KELLY PRIME: When Harrison finished H4, he didn’t do what he’d done with his other inventions. He didn’t insist that this one wasn’t right or ask for more time. He was finally, finally ready to have his work tested and collect the Longitude Prize. 

DAVA SOBEL: Perfectionist, you think? Yeah. So that’s what was one of the most interesting things to me–that when he made H4, he knew he’d really done it. And he had this wonderful saying. I think I remember it. “I think it is fair to say that there is no other mechanical thing that is as beautiful or as curious in texture as this my watch or timekeeper for the longitude.”

ROMAN MARS: Satisfied, finally, with his invention, Harrison presented H4 to the board of Longitude. The board agreed to send the timepiece on its official trial to Jamaica, with that big fat pile of quid resting on the results. 

KELLY PRIME: To take top prize, Harrison would need to bring H4 by sea to Jamaica and then, on arrival, take longitude calculations. If the difference between Harrison’s number and the real longitude of Jamaica was within 30 nautical miles, or half a degree of longitude, he would at long last take home the prize. 

ROMAN MARS: Harrison himself was getting up in age. He was almost 70. So in classic dad fashion, he made his kid do it. 

KELLY PRIME: In 1761, Harrison’s son, William, traveled with H4 all the way across the Atlantic Ocean on a two-month journey through icy cold, humid heat, and rolling seas. He collected his data, which was accurate to about a single nautical mile–way closer than the 30-mile cutoff. 

ROMAN MARS: But when William returned home expecting to claim the reward, the Board of Longitude said that, sorry, actually, the trial was void–partly because they thought the result might be a fluke, and partly because they didn’t actually know the longitude of Jamaica. 

KELLY PRIME: They sent him to Jamaica, even though they weren’t sure where Jamaica was. This was insane behavior–a huge waste of time. Obviously, the Harrisons were exasperated. 

ROMAN MARS: From this point on, the Board of Longitude kept holding the prize just out of reach. In 1764, Harrison got a new trial, this time to Barbados. He aces it again, but the Board equivocates. 

DAVA SOBEL: You know, they kept moving the goalposts. 

KELLY PRIME: Harrison may have finally perfected his watch, but his timing was horrible. It took him so long that, by this point, most of his friends and allies on the board had retired or just straight up died. 

ROMAN MARS: And the new commissioners of longitude were unfortunately the worst thing an eccentric creative type could encounter. They were pragmatists. Here’s Alexi Baker again. 

ALEXI BAKER: The big problem–the reason he was conflicting with the commissioners–is they thought it wouldn’t help the nation if they couldn’t also replicate his watches. 

KELLY PRIME: The Board of Longitude was looking at Harrison and saying, “This is a guy who’s over 70 years old.” He’d taken decades to build one watch, and they weren’t even sure he could make a second one, let alone put them in the hands of every captain trying to make their way across the open seas. 

ALEXI BAKER: So they could be amazing one-offs, but would it be affordable and possible, because he was getting on an age, for others to make a lot more watches? 

ROMAN MARS: Not to mention that Harrison had in fact been so slow that the astronomers who had taken centuries to find a solution to longitude had basically caught up. They actually had found an okay way of calculating longitude called “the lunar distance method.” And it worked, as long as you had a highly educated person on board, a set of tables, and several hours of calculation time to spare. 

KELLY PRIME: The Board of Longitude kept setting up new hoops for Harrison to jump through. Harrison lost his patience, and he and his son William started publishing attacks against the board. 

ALEXI BAKER: I honestly, even though it’s silly to feel sorry for people in the 1700s, feel sorry for both the Harrisons and the commissioners because they both had very valid points. And also you can definitely understand John Harrison was old by the standards of the time. He was tired. He had more medical ailments. He wanted this solved and to get his reward, you know? 

KELLY PRIME: It’s like he just wants to be done with this [BLEEP] clock. 

ALEXI BAKER: Yes, it had been his whole life since the 1730s. 

KELLY PRIME: In the end, Harrison and his son decided to pull the boldest, most daring card they had up their sleeve. They tattled. 

ROMAN MARS: William Harrison personally appealed to famous clock enthusiast and America loser King George III to step in. 

DAVA SOBEL: There were many reasons to cry, “This is unfair.” And the King agreed that it was unfair and tested the fifth one in his private observatory and was convinced that Harrison had been very badly treated. 

ROMAN MARS: Speaking to William at Windsor Castle, the King supposedly said that they had been cruelly treated and exclaimed, “By God, Harrison. I will see you righted.”

KELLY PRIME: In 1772, King George tested a copy of H4 called, you guessed it, “H5,” and was thoroughly impressed by its accuracy. At the instruction of the King, Parliament awarded John Harrison the rest of the money he was owed as a thank you for his decades of work. 

ROMAN MARS: Crucially though, the money was only a thank you. It was not the Longitude Prize, which the board maintained he had not earned. 

ALEXI BAKER: Of course, he felt hard done by. He was probably never fully happy, even after he got that recognition. 

ROMAN MARS: Harrison died in 1776, just a few years later. And it did take a minute, or more like a few decades, for manufacturers to even come close to replicating the near perfection of H4. But by the early 19th century, variations of Harrison’s Sea Watch were everywhere. These instruments became generically known as “marine chronometers.”

KELLY PRIME: Unfortunately, the marine chronometer did exactly what Parliament had hoped when they first set up the Longitude Act over a century earlier. It threw gasoline on the fire of British imperialism. The Royal Navy made marine chronometers standard issue. And captains of merchant vessels, like those sailing with the British East India Company, got their own chronometers, too. Here’s Dava Sobel again. 

DAVA SOBEL: And once they really knew where they were going and where they were, that was a powerful aid to many things they did for good and ill. 

ROMAN MARS: By the time marine chronometers were widespread, Britain had abolished slavery and left the transatlantic slave trade. But it was colonizing faster than ever, spreading beyond North America and the Caribbean and into Africa, Asia, and the Pacific. And since any tool that helped navigation helped imperialism, the marine chronometer was a key part of the evildoings. 

KELLY PRIME: In the end, the marine chronometer ended up being just one tool in a toolbox full of tools that the British used for world domination. But actually, one of the chronometer’s most lasting impacts came indirectly from its role in map making. 

ROMAN MARS: James Cook used his Harrison-style chronometer on his second voyage. He took it south of the Antarctic Circle, where he surveyed parts of the world never before represented on European maps. And the logbooks on his ship, the HMS Resolution, called the chronometer “our trusty friend, the watch.”

KELLY PRIME: In 1831, the surveying vessel, the HMS Beagle, carried Charles Darwin to the Galapagos. It also carried 22 marine chronometers. You know, just in case… 

DAVA SOBEL: Bare minimum, you’d have a few because you would use them all and then compare them. You want to have backup. You always want to have backup. 

KELLY PRIME: The widespread use of marine chronometers meant that, by the late 19th century, most Western trading vessels were using British maritime charts. So when a global conference was held to pick one standard line of zero degrees longitude for the international community, the choice was obvious. 

ROMAN MARS: Greenwich, England, was chosen as longitude zero, the prime meridian. And with that, England–with the help of John Harrison–became, cartographically speaking, the center of the world. 

KELLY PRIME: I wonder how having longitude changed navigation. 

TODD STEVENS: People stopped dying so much. 

KELLY PRIME: Back on the Buccaneer with Todd, as he was steering us through jagged rocks and hundreds of shipwrecks, I didn’t take for granted that I could just look at the dashboard and get information that, a few hundred years ago, would have seemed like a miracle. 

KELLY PRIME: You’re looking at the screen right now. What is that? 

TODD STEVENS: That’s a GPS that shows you where all the rocks are and where all of the wrecks are. I’ll put them on there. 

KELLY PRIME: And what’s our longitude right now? 

TODD STEVENS: Our longitude… We’re north. North. 4 9 5 3 3 4 0 West 0 0 6 21 3 6 8. 

KELLY PRIME: Good to know. 

ROMAN MARS: After the break, we talk about a method for long-distance sea travel that existed millennia before Europeans cracked longitude. 

[AD BREAK] 

ROMAN MARS: So I’m back with Kelly Prime. I hear you have some more for me. 

KELLY PRIME: I do! So as I was reporting this story, one element kept coming up for me, which is that the story we’re telling about longitude and the longitude problem and the act is a very Eurocentric one. Like, yeah, I can’t actually picture any of these characters not wearing powdered wigs. You know? 

ROMAN MARS: [LAUGHING] Totally. That’s totally true. 

KELLY PRIME: And since the problem of finding longitude was essentially the problem of figuring out a way to safely travel long distances at sea, I was really curious about how other cultures managed to do that. And the most extraordinary version that I found comes from the Pacific Islands, where navigators have been traveling between these, like, teensy tiny islands separated by thousands of miles of ocean for millennia, like centuries and centuries before the Longitude Act. So to find out more, I called up probably one of the coolest people I’ve ever met.

LEHUA KAMALU: My name is Lehua Kamalu. And I am a captain and navigator and sometimes crewmember of traditional Polynesian voyaging canoes. 

KELLY PRIME: Lehua Kamalu is based in Honolulu and works on the canoes Hōkūleʻa and Hikianalia. And she’s one of the few people on Earth using traditional skills to navigate vast distances at sea, which means no GPS and definitely no marine chronometer. 

LEHUA KAMALU: There is no timepiece involved in the wayfinding in this way. And so I’ll probably call it “non-instrument navigation.” That’s probably the simplest way to describe it. 

ROMAN MARS: I mean, to me, there is nothing simple about navigating thousands of miles between tiny islands in the middle of the Pacific Ocean, but… How does she do it? 

KELLY PRIME: Yeah, well, I’ll say first that a lot of the original techniques for this kind of navigation have been lost over the years because of colonization. But Lehua and her colleagues use their own interpretation of the methods the Pacific Islanders used thousands of years ago. Back then, navigators in the Pacific Islands had a lot of the same challenges as Europeans. Basically, there’s only so much information you can easily get from the sun and the stars. And so it kind of makes sense that the starting point for Polynesian wayfinding is actually pretty similar to the European concept of dead reckoning. 

LEHUA KAMALU: Your need to constantly be watching, like, “Are we making good progress? Are we still doing the same speed? Are we a little slower? Are we a little faster? You know, are these conditions the standard conditions that we expect? Or are we experiencing something that is out of the norm? And how do we account for that?” 

KELLY PRIME: Ultimately, though, this approach isn’t enough. Lehua says it gets you in the right direction, but the longer the journey, the more errors can add up. So you need a way to get more confident in where you are and where you’re going at sea. And so instead of using something like latitude and longitude, Polynesian wayfinders take a more holistic approach. 

LEHUA KAMALU: Let’s just imagine the world, not so much with an imaginary grid on it, and rather just see it in the natural way that it is. And I think what it forces you to do is to allow nature to tell you where you are and not you to tell nature where you are. 

ROMAN MARS: And what does that mean exactly–letting nature tell you where you are?

KELLY PRIME: Okay, so what Lehua told me is that even when you’re out at sea, way out of sight of land, that doesn’t mean you don’t have information. In fact, your natural surroundings provide a lot of data that can be used to figure out where you are and where you’re going. 

LEHUA KAMALU: It’s not that you are traveling from point A to point B with absolutely nothing in the middle. There’s an ocean that is pointing you in the right direction. There are wave patterns. There are animals. There are wind directions. There are clouds in the sky. There is a never-ending display of celestial bodies of planets and stars and the sun and the moon and all these features that are continuously telling you what direction you’re going in if you’re paying attention. 

ROMAN MARS: So I think I understand that there are these natural features in the environment that you can use to navigate. But how does she apply what she’s seeing and hearing? Like, how does she make practical sense of it all in terms of setting a specific course for her canoe? 

KELLY PRIME: Great question. And one example that Lehua gave me was birds, specifically land birds. So, you might be trying to locate one little island in the Pacific and you could be out of sight of land. But if you look up and see a land bird flying overhead, like a type of bird that you know doesn’t like to go very far from home, that tells you something. And it means you’re in the radius of some kind of land. 

LEHUA KAMALU: And suddenly you see that island–if you imagine the island not just as the land above the water, but also the animals and the birds that live on that island–they are part of that island as well. So the island becomes much bigger. And soon you start to say, “Well, also the waves around that island are affected much further out.” So, in a way, those waves are also part of the island. And suddenly the island is actually just this massive target. And if you start to see all the signs that say “I’m an island,” it’s not just land, right? You don’t just have to see a rock or a tree to know an island is there. And I think that suddenly makes you realize how going after one island that might only be 10 miles around becomes going after an island that’s 200 or 300 miles around. And you’re trying to expand your perspective to see the ways that you can see an island without actually just seeing the island itself. 

ROMAN MARS: I love this so much. This was so cool! 

KELLY PRIME: It really is. 

ROMAN MARS: So, okay, she can see a 10-mile island as a 300-mile island. That’s amazing. But I do wonder–as you are relying on the natural world to be your sort of navigational guide–that climate changes and changes in the environment could change the way she should read them. Did she talk about that? 

KELLY PRIME: She did because, like you’re saying, with the entire basis of your navigation system is the natural world, even the tiniest changes to one ocean current or one species of bird can make a massive difference. 

LEHUA KAMALU: Really something I think about a lot today is just how much life in the ocean is no longer there. When you think about how critical just that one bird is, you start to connect all of the sensitivities of the system. And it all has to work for it to work for you. So you become quite attentive to what supports the system that allows the navigation. And that is a healthy ecosystem. 

ROMAN MARS: I mean, you think about one species of bird that lives on an island. And if something happened to that one species, she would know the difference. It would affect her navigation potentially. It’s just sort of an amazing concept to think about.

KELLY PRIME: Yeah, she actually talked about feral cat colonies on islands and how, when there’s feral cat colonies, those cats will kill the birds. And when you don’t have the birds, you don’t have the bird at sea. So even one tiny, tiny thing throws off how you can find where you are in the ocean. It’s kind of crazy. 

ROMAN MARS: It is crazy. It’s so interesting. 

KELLY PRIME: So I also want to mention that Lehua and her colleagues at the Polynesian Voyaging Society are currently doing this big project to circumnavigate the Pacific on traditional voyaging canoes. It’s a 43,000 nautical mile voyage. And Lehua is one of 400 crew members taking turns doing different legs of this journey. And the day I talked to Lehua, she was getting ready. It was literally the day before she was getting ready to fly out to start a 2,000-mile journey from the Cook Islands to New Zealand. And the whole voyage should take about four years. I think they started in 2023. 

ROMAN MARS: Wait. And she was getting on the phone to talk to you the day before she was leaving on his four-year journey. 

KELLY PRIME: Yeah, she was like, “I should really, really pack.” But this wasn’t– She’s doing one leg of the journey. She was going to do one leg.

ROMAN MARS: Okay, that sounds better. Okay. That sounds good. 

KELLY PRIME: Yeah, so the whole voyage should take four years. And the goal is to connect communities in the Pacific and also to spread awareness about the importance of protecting indigenous knowledge and ocean ecosystems. 

ROMAN MARS: So is there a way to track where she is in the world? 

KELLY PRIME: There is, yeah. So you can go to the Polynesian Voyaging Society website, and there’s a map that lets you track the journey–the various legs of the journey. 

ROMAN MARS: That is so cool. I’m so glad we talked about this. This is so much fun. 

KELLY PRIME: Thanks, Roman. It’s been really fun. 

ROMAN MARS: 99% Invisible was reported this week by Kelly Prime, and edited by Vivian Le. Mix by Brendan Byrns. Music by Swan Real and George Langford. Fact-checking by Graham Hacia.

Special thanks this week to Richard Dunn, Rebeckah Higgitt, Trevor Newman and Terry Hiron.

Kathy Tu is our executive producer. Kurt Kohlstedt is our digital director. Delaney Hall is our senior editor.

The rest of the team includes Chris Berube, Jayson De Leon, Emmett Fitzgerald, Martín Gonzalez, Christopher Johnson, Lasha Madan, Joe Rosenberg, Jeyca Medina-Gleason, Talon and Rain Stradley, and me, Roman Mars. The 99% Invisible logo was created by Stefan Lawrence.

We are part of the SiriusXM Podcast Family, now headquartered six blocks north in the Pandora building… in beautiful… uptown… Oakland, California.

You can find us on all the usual social media sites, as well as our new Discord server. There’s a link to that, as well as every past episode of 99PI, at 99pi.org.