Geographic Frontiers



Christopher Columbus and his “Sailing West to Asia” Start-up
— The Geographic Backstory.

How Columbus got lucky in his initial discovery but ended up getting kicked out of the enterprise he founded.

Christopher Columbus has fallen into disfavor over the last several decades. As a child in elementary school over 60 years ago, I dutifully celebrated Columbus not only as the discoverer of America, but the brave mariner who dispelled once and for all the notion of a flat earth.

The people Columbus encountered rightfully could claim they were there all along. Columbus and many of the Europeans who travelled with him treated them cruelly. A lot of people in Columbus’s time were aware the earth was round. He might not have been brave as much as obsessed with his idea of sailing west—not to America—but to Asia. In coming up with the idea for his journey, the only issue--as far as Columbus was concerned--was how far away to the west was Asia.

Like most start-up founders, Columbus brought a belief and a persistence that enabled to him to get funding for his endeavor. He wasn’t the first to consider sailing west to Asia. Columbus was not a scientific wizard who recognized a physical truth that had escaped others. He was no Newton with gravity or Galileo with a sun-centered solar system. Like many founders who are passionate about their idea, he highlighted his experience and used data favorable to his vision. He even threw in divine appointment for good measure.

European monarchs were interested in trade access to Asia. They had taken a liking to the exotic spices that only seemed to be available from Asia, and there was considerable mark-up for spices meaning more money in the treasury. The journey east was fraught with challenges. Muslims controlled most of the land routes.

Columbus simply needed to find or--if need be--create the data to sell potential royal sponsors on his plan. A start-up founder must be persistent to get funding. Columbus certainly was. He made his first pitch to King John II of Portugal in 1484. (Since we all know Columbus sailed the ocean blue in 1492, this means it took him eight years to obtain his initial investment.) King John had his experts evaluate Columbus’s proposal, and they felt Columbus came up significantly short in estimating the distance to Asia. Columbus tried Ferdinand and Isabella of Spain in 1486, but their experts came to the same conclusion as King John’s. Columbus even sent his brother, Bartolome, to England to make his case before King Henry VII. (Pirates intervened and Bartolome was unable to complete his voyage.) After a couple of additional pitches to Ferdinand and Isabella, the time became right in 1492. Ferdinand and Isabella were flushed with the success of removing Muslims from Spain. They no longer needed to expend funds on war. Ironically, they were persuaded not so much by the feasibility of Columbus’s proposal but rather as a hedge to ensure other competitors—that is neighboring monarchs—wouldn’t somehow capitalize on Columbus’s idea. Ferdinand and Isabella became Columbus’s angel investors. It turns out they were a little short on cash. They could only give Columbus money for one ship when he needed three. The monarch resolved this problem by requiring the city of Palos, which owed the Spanish crown a fine for piracy, to pay up by loaning two ships to Columbus.

In the end, it wasn’t his data and analysis as much as plain old luck (or just maybe that divine appointment thing) that brought him initial success. Columbus set sail in 1492 convinced the earth was smaller than it actually is, and Asia was a good bit larger. Fortunately for him, there was a sizeable land mass—now called North and South America--between him and Asia. Had it not been there, he likely would have turned back. It wasn’t a small world after all.

Columbus is like some modern-day start-up founders who are steadfast in their vision, but lousy—to say the least in his case--in how they treat others once things get going. Some founders stay on too long, but eventually are forced out. The same happened to Columbus. By his third voyage, his deadly treatment of both Spanish settlers and indigenous peoples caught up with him. He did manage to convince his investors to fund a fourth voyage, but they had fired him as governor.

What did Columbus include in his start-up pitch? We’ll look at three things. Columbus likely highlighted his experience as a navigator. He cherry-picked data to fit his notion that it was a small world. He threw in divine appointment perhaps due to his own beliefs but certainly to appeal to the beliefs of his potential investors. All three have a geographic backstory.

Columbus the Navigator

Navigation is rooted in geography but has grown so sophisticated it is often separated from its origins. Knowing where one was and how to get to where one needed to be was the motivation behind early geographic treatises. The navigation techniques and maps used by Columbus—although primitive by today’s standards—grew out of the work that began with the geographers of antiquity.

All indications are Columbus was a pretty good navigator. There was no way to assess the comparative abilities of navigators of his age other than that they got to their destination and returned safely. Columbus did this reliably.

If you have visions of Columbus standing at the rail of his ships and “shooting” the stars to determine his position, you would be mistaken. Columbus used a brute force form of navigation known today as dead reckoning. (There is some debate as to the origin of the term. I always thought it came from the idea that if you reckoned wrong, you would miss your target location and end up dead. Turns out that’s definitively not the origin of the term.)

We know a great deal about Columbus’s navigation techniques because he kept detailed logs of his journeys. His tools of the trade were a compass, some flotsam, a sandglass and maybe some tables that provided the times for sunrise and sunset for each day of the year.

The process was rather straightforward. Columbus stuck to a bearing on his compass. Since he was sailing west to Asia, he kept his ships generally pointing west. Knowing his direction, the next thing he needed to know was his speed. This was determined by throwing a flotsam overboard—usually a piece of wood with a rope attached—and seeing how fast it traveled the length of the ship. An experienced sailor would say a rhyme or a chant at a consistent cadence to mark time. The third piece was to know the elapsed time. This was accomplished via the sandglass which was usually turned every half hour at which time the flotsam measured speed was also recorded. The time derived from the sandglass could be recalibrated based on an observable sunrise, high noon, sunset or perhaps by the shift of constellations in the night sky.

Good navigators—like Columbus—had to be very deliberate in ensuring the compass bearing was maintained, the sandglass was turned every half hour, and speed was recorded. Good navigators—like Columbus—often kept best and worst-case estimates of their position. On his first voyage, Columbus only shared his best-case estimate with the crew. It turned out to be fairly accurate.

With two entire unknown continents to the west, it wouldn’t require much in the way of navigational skill to eventually hit land. On the other hand, knowing how far he traveled was important since he had already “calculated” how far west he would need to sail to reach Asia.

Columbus did take a stab at celestial navigation. Once he reached the islands in what we now know to be the Caribbean, Columbus recorded his efforts to determine his latitude using a device called a quadrant. He was off by about 20 degrees. It was a good thing he had dead reckoning down.

Good navigators also had some skill in understanding weather. Columbus’s experience may have involved as much luck as skill. He was probably no better or worse than other navigators of his day in understanding the vagaries of wind and weather. He sailed to the Canary Islands off the coast of Africa before heading west planning to take advantage of prevailing winds coming from the northeast. While this worked for him on his first voyage, he could have just as easily encountered a hurricane. Although there was substantial disagreement as to who was a fault, the Santa Maria did run aground off the coast of what is now Haiti while Columbus was on board. (It wasn’t the only time he ended up beached on his voyages.) On his return voyage, Columbus planned to go by a more northerly route to take advantage of “westerlies” to carry him back to Europe. Now on the Nina, his ship did encounter storms, forcing him to make unplanned stops in the Azores (where he was imprisoned for a couple of days for suspicion of being a pirate) and Portugal. Columbus always managed to return alive which, by my criterion, placed him in the class of reasonably good mariners for his time.

It is believed Columbus got into the sea business at an early age. Columbus wrote that he went to sea at the age of ten. This could have been an exaggeration. Although Columbus was the son of a wool merchant involved in the weaving trade, his birthplace of Genoa--an independent republic in what is now Italy--was known for its seafarers. If you’re the son of a store owner in Silicon Valley, the tech influence could be such a draw that you decide to study computers. It appears that the Genoa’s seafaring reputation drew Columbus to the sea. While we can’t be sure when he started his apprenticeship, by his mid-twenties, he was sailing outside the Mediterranean to England and possibly to Iceland.

Almost two centuries before Columbus’s now famous voyage, the Portuguese king enlisted the help of the Genoese to enhance his kingdom’s seafaring capabilities. This led to the creation of an influential Genoese colony in Lisbon, Portugal. In 1477, Columbus settled into Lisbon where his brother, Bartolome, was working as a map maker. He married the daughter of a Portuguese nobleman which—tasting a bit of the noble life—may have motivated Columbus to come with an idea of how to achieve wealth and fame. It makes sense, then, that the Genoese ship captain Christopher Columbus would target Portugal’s King John as his first investor.

It's a Small World After All

With established credentials as a navigator, now Columbus had to convince others—as he had already convinced himself—that Asia was not that far to the west. The geographic backstory involves a well, faulty measurements, a Muslim scholar, and Marco Polo.

Let’s begin our story some 1700 years before Columbus with the well. This particular well was in the Egyptian city of Syene, now modern-day Aswan. In the 3rd century BC, this well had gained some notoriety because the sun shone directly to the bottom of the well at noon on the summer solstice.

Five hundred miles to the north, in Alexandria, lived Eratosthenes. Eratosthenes was a polymath known for accomplishments in mathematics, astronomy, music theory, and geography. Born in North Africa and educated in Athens, he was chosen to run the Great Library of Alexandria. In terms of geography, his most recognized accomplishment was a remarkably accurate calculation of the earth’s circumference

One summer solstice at noon, he measured the sun’s shadow in Alexandria. Knowing this angle, and the distance to Syene where the angle was zero, he had all he needed to calculate the earth’s circumference. He came up with the figure of 252,000 stadia.

This presents a problem we encounter at least up to the time of Columbus--uncertainty over the length of the unit of measurement used by the geographer. In the 3rd Century BC, there were at least two versions of stadia in use with the Greek version being about 90 feet (27 meters) longer than the Egyptian version. If Eratosthenes used the longer, Greek version, he would have postulated the world to be 16% larger than it actually is. Examining the linear distances Eratosthenes used elsewhere in his work, it appears he used the Egyptian figure of about 517 feet (157 meters) per stadion. This would place his result to within 2% of the earth’s actual circumference.

It helpful that Eratosthenes wrote a book about his accomplishment. In fact, he is first person we know of who wrote a book about geography which he gave the arresting title: Geography.
(Original versions of Eratosthenes’s Geography are lost. What we know about it comes from later writers who referred to it.) In addition to describing how he calculated the earth’s circumference, Eratosthenes developed a grid system--analogous to our modern-day latitude and longitude system—to describe the location of over 400 cities in the ancient world along with a means to calculate distances between them. As a geographer he wanted to help others navigate from one place to another.

If you’re a mathematician, it seems that others always want to check your work.

About 150 years later, Posidonius of Rhodes, a Greek astronomer, believed he could correct some of the perceived errors in Eratosthenes’s work. Instead of using a well in Syene he used the star Canopus. He measured the angle of Canopus above the horizon at Alexandria knowing that it touched the horizon at Rhodes. Knowing the angle and the distance between Alexandria and Rhodes, he had the information he needed to make his calculation. Posidonius had the misfortune of making errors in both measurements. Initially his two mistakes cancelled each other out and he got an answer close to that of Eratosthenes. The headline: Eratosthenes’s Circumference Confirmed!

But remember, if you’re a mathematician, it seems that others always want to check your work.

Like Eratosthenes, Posidonius’s original work is also lost. We are reliant on intermediate authors to convey Posidonius’s efforts and who sometimes put their own spin on what earlier geographers wrote. Either Posidonius or someone associated with him had doubts about his initial results and likely corrected the Rhodes to Alexandria distance, but not the star’s angle. The result, reported by later sources, was a much smaller circumference of 180,000 stadia. Regardless which stadion length one choses, the 180,000 stadia result is much smaller than the earth’s actual circumference by 17% to almost 30%.

Around 100 AD another multi-volume Geography appears, this one written by Claudius Ptolemy. Like Eratosthenes, Ptolemy lived in Alexandria, and he was a polymath. In addition to his contributions to geography, Ptolemy is known for the earth-centric model of the universe he developed. (One can’t be right about everything.) Claudius Ptolemy’s influence was perhaps the greatest of the early geographers for two reasons. Not only did his work survive relatively intact until the Renaissance twelve centuries later, he drew maps that looked good. One problem, though, is that his maps were a bit distorted because he insisted on using the 180,000 stadia circumference attributed to Posidonius. His maps would have looked even better if he had stuck with the Eratosthenes’s figure. It’s not entirely clear why he chose the 180,000 figure. Perhaps he was influenced by near contemporary, Marinus of Tyre, who also used the 180,000 stadia figure. Maybe Ptolemy liked rounder numbers. 180,000 divided by 360—the number of degrees in a circle yielded 500—is a much easier figure to work with than the 700 stadia per degree that resulted for Eratosthenes’s circumference.

In an age of transportation via foot, sailing ship or horses, a smaller earth is good news. One doesn’t have to travel as far to get where you’re going. This appeal of the 180,000 stadia figure attributed to Posidonius and perpetuated by Ptolemy lasted until Columbus’s day. Columbus had a copy of Ptolemy’s work. Although it turned out to be wrong, it was better news for Columbus than the Eratosthenes circumference which the naysayers used to persuade the royals that Columbus’s proposal was not worth funding.

The next character in the earth’s circumference story is a Muslim scholar, known in the west as Alfraganus. (His Arabic name was Abū al-ʿAbbās Aḥmad ibn Muḥammad ibn Kathīr al-Farghānī.) Arabic Rulers of the Abbasid Caliphate--which began in the 8th century--put resources into scholarship and learning, even building an intellectual center in Baghdad called the House of Wisdom. They placed an emphasis on translating Greek texts into Arabic. Ptolemy’s work was included in this effort. Alfraganus, who did his work in the 800’s, used Ptolemy’s work as a basis for his writings on astronomy and geography. In his work, he provided his own calculations related to the earth’s circumference. He calculated 56.7 miles per degree. This turned out to be a fairly accurate estimate so long as one realizes that an Arabic mile was longer than the Roman mile. Alfraganus’s work was translated into Latin in the 1100’s and is thought to have influenced, among others, a 15th century French cleric named Pierre D’Ally who wrote his Imago Mundi (Image of the World) in 1410.

The New World would not have been discovered were it not for the printing press. Columbus had printed copies of D’Ally’s Imago Mundi and The Travels of Marco Polo. He or his brother made notes in the margins of each. He also had access to Ptolemy’s Geography.

It’s easy to guess that Columbus settled on the lower Posidonius and Ptolemy 180,000 stadia figure for the earth’s circumference. He may have recognized a problem that others had encountered. There were plenty of definitions for how long a stadion might be. As mentioned previously, depending on which distance he chose, the earth’s circumference could have been reduced 17% to 30% of its 25,900-mile value.

It appears Columbus came up with a way to get it smaller. From D’Ally, he got the 56.7 miles per degree estimate of Alfraganus. Instead of using the Arab mile, like Alfraganus did, Columbus used the smaller Italian mile (4060 feet) which was a length that he and other European navigators used during the time period. This resulted in an even more manageable 38% reduction in the earth’s circumference to about 16,000 in modern-day miles. There is no evidence that Columbus ever tried to validate the actual distance of a degree during any of his voyages. After all, while Columbus was reasonably good a brute force dead reckoning, he was lousy at celestial navigation.

The second leg of his pitch relied on making Asia much bigger than it actually is. For this, his inspiration was an Italian named Paolo dal Pozzo Toscanelli.

Toscanelli was a polymath of sorts—primarily mathematics and astronomy--who lived in Florence around the time of Columbus. (Living into his eighties, Toscanelli died in 1482). He also had an interest in geography accepting Marco Polo’s claim of an elongated Asia. (Columbus also studied The Travels of Marco Polo.) In 1474, Toscanelli sent a letter to an acquaintance in Lisbon, a priest who was also the king’s confessor, with the idea of sailing west to Asia. His friend delivered the letter to the Portuguese king--networking existed even in the 15th century--but it didn’t appear to get traction. Columbus settled into Lisbon a few years later and likely heard about the letter and Toscanelli’s idea. It’s hard to say if Toscanelli’s big idea was adopted by Columbus or if Columbus was attracted to Toscanelli because he shared a similar view. Toscanelli sent a copy of the letter along with a map to Columbus. Columbus took Toscanelli’s map with him on his first voyage.

By one estimate, Toscanelli’s map placed Cipango (Japan) about where the western coast of southern California and northern Mexico is located. Another estimate says Columbus thought he’d run into Cipango about where western Cuba is. This fit nicely into Columbus’s vision. He calculated that the ocean separating Portugal from Cipango was one-seventh of the earth’s circumference, or about 2,400 miles. He figured that by sailing about 100 miles per day, he could reach the Indies in 30 days. It took him 36 to reach what he thought were the Indies. The actual distance was closer to 3600 miles (from the Canary Islands), so he did manage to sail about 100 miles per day.

Columbus the Divine

Columbus had experience as a navigator. He had the geographic data—albeit incorrect--to back up his claim that Asia was within sailing distance to the west. Even his divine inspiration had a geographic component.

As part of his argument for a large Asia not being too distant to the west, he referred to a verse in the Roman Catholic apocrypha. 2nd Esdras 6:42 reads: “Upon the third day thou didst command that the waters should be gathered in the seventh part of the earth: six parts hast thou dried up, and kept them, to the intent that of these some being planted of God and tilled might serve thee.” If six sevenths of the earth are dry land, he reasoned the ocean to the west could not be very large.

There are also indications Columbus believed his sailing west had divine purpose. How much of this was his own belief and how much was pandering to Isabella’s and Ferdinand’s own religious beliefs we cannot know for sure. After a trouble filled third voyage, Columbus wrote his Book of Prophecies which cataloged views on how his explorations could help bring about the second coming of Christ. A key part was the riches he expected to find Indies. This wealth would fund the Army needed for a Spanish monarch--the “last emperor”—to conquer the Holy Land from the Muslims thereby enabling Christ’s return. Isabella and Ferdinand had distinguished themselves by removing the last Muslims from Spain (along with expelling Jews and initiating the Spanish Inquisition to ensure no imposters stayed behind). Echoing this accomplishment by having them remove the Muslims from Jerusalem, may have been part of his pitch to the Catholic Monarchs of Spain appealing to their apocalyptic destiny.


There are any number of terms used to describe when things become “real” for a startup. In Columbus’s case, it became real for him when he saw land. His startup had launched. Columbus’s first voyage accomplished what he thought it would. He found land about where he thought it would. He was convinced he had reached islands near Asia and the riches of Cipango and Cathay (China) could not be far. Within a decade, led by Spain, other European countries were sending ships to the region. Consensus was developing that an entirely new set of lands had been encountered. Another Florentine Italian, a navigator named Amerigo Vespucci, after sailing along much of the coast of what we now call South America, came to this conclusion. On a map published in 1507, a German cartographer took the liberty of recognizing Vespucci’s claim and identifying the new land with a Latinized version of his first name. In today’s world, a seemingly random tweet can bring fame or destroy one’s reputation. In the early 16th century, one person deciding to put another person’s name on a map led to the permanent names of continents and a country.

After four voyages and with deteriorating health from a life at sea, Columbus returned to Spain where he died in 1506, two years after returning from his last voyage. It’s not clear whether Columbus fully recognized that his startup idea—sailing west to Asia—didn’t quite work out as planned. Instead of Asia, he had reached an unknown continent. When one is so committed to an idea, it is hard to give it up even in light of compelling new evidence.

The Aftermath

Like most start-up founders, Columbus brought a vision and persistence that enabled to him to get funding for his endeavor. Unfortunately, like some founders, Columbus was not that great at implementation. Named viceroy and governor of all the islands he discovered, Columbus began his second voyage with 1,400 men on 17 ships. One of his mistakes was to return to Spain from his second voyage with 500 slaves when Queen Isabella, his principal backer, deplored slavery. By his third voyage, he had brought along his brothers to run his colony with him. Their harsh treatment of both Spanish settlers and indigenous peoples got them into trouble during the two and a half years they were in what we now call the Caribbean (named after an indigenous tribe Columbus encountered). Perhaps recognizing that he wasn’t that good at running things, when Columbus sent some mutinous settlers back to Spain, he requested an experienced administrator. Ferdinand and Isabella obliged. To get an idea of how bad things were, when the new governor arrived, the first thing he saw were the corpses of six rebellious Spanish settlers hanging from posts. Columbus and his brother Bartolome had gone exploring inland leaving their youngest brother, Diego, in charge. Diego informed the new governor that more settlers were scheduled to be executed the next day. The executions were cancelled, and Diego was arrested along with Columbus and Bartolome when they returned to the settlement. All three were returned in chains to Spain. It was left to his benefactors, Ferdinand and Isabella, to exonerate him, although they deferred in reinstating Columbus as governor. They recognized his talent for navigating and sailing ships but knew he couldn’t run a larger enterprise.

Columbus didn’t exactly die a pauper, but the Spanish royalty withheld funds and titles he was originally promised. He had no grand state funeral. The luster of his big discovery was overshadowed by the mess he made when he tried to run things in his new colony. After Columbus died, his heirs sued the Spanish royalty for the funds and titles Columbus had been denied and received a final ruling in their favor some 30 years later.

When it comes to financial reward, the analogy to a startup really starts to fall apart. Modern capitalism didn’t really start until about 100 years later in Holland when the Dutch East India Company became the first publicly traded company. The irony is they made their money sailing east to India rather than west to the Americas. Since all the initial wealth from Columbus’s territorial claims went first to the Spanish monarchy, it’s difficult to calculate a reliable return on investment. But, like the storied Silicon Valley tech company founders working out of a garage, Columbus started something big.

No story would be complete with some fake news. The whole story of Columbus dispelling the idea of a flat earth is just that—fake news. It arose from a book by American author Washington Irving who was living in Europe in the 1820’s and had access to the American ambassador to Spain’s library. Irving’s A History of the Life and Voyages of Christopher Columbus was a romanticized biography of the famous navigator. Perhaps wanting to cast some disparagement toward Catholics, Irving put forth the notion the Spanish theologians of Ferdinand and Isabella’s court persisted in the notion the earth was flat, and an enlightened Columbus set out to prove them wrong. That fake news lasted a long time. I was told that tale as a child over a 130 years later.

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