Accessory to War

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Accessory to War Page 10

by Neil DeGrasse Tyson


  had lived in perdition of soul and body: of their souls in that they were yet pagans without the custom of reasonable beings . . . and worst of all through the great ignorance that was in them, in that they had no understanding of good, but only knew how to live in a bestial sloth.

  Translation: If you despise the way certain people live, you’re entitled to take everything they own, and you’re officially free to use force to do so.40

  A quarter century after Henry’s death, King João II of Portugal (o Príncipe Perfeito, “the Perfect Prince”) picked up where his uncle had left off. In 1484 he called together a group of savants from across Europe to work out rules for calculating latitude based on direct observation of the Sun’s midday altitude. Their findings were published in a comprehensive manual of navigation called the Regimento do astrolabio e do quadrante. It includes a list of latitudes spanning the territory from Lisbon to the equator, nearly all of which are correct to within half a degree. It even includes a translation of Sacrobosco’s On the Sphere of the World. Word was getting around again: the world was not flat. Geographers began to wrap their maps around a globe, while astronomer-astrologers kept themselves busy refining the coordinates of naturally occurring astronomical objects and phenomena.41

  Besides seeking slaves, converts, and knowledge, the expeditions of the fifteenth century—the early part of what the maritime historian J. H. Parry calls the Age of Reconnaissance—sought gems and precious metals, spices and medicaments, good land for growing sugarcane, grapes, coffee, and tobacco, new fishing grounds, new pastures for sheep, new sources of timber of a suitable size for masts and palaces.42 But as each ship’s hold filled with the products of faraway places, and each ship’s captain returned to tell his tales to eager listeners, it became increasingly obvious that all this adventuring, conquering, colonizing, commodifying, and profiteering also required that every captain become expert at determining the exact location of his vessel, his destination, and his home.

  Fifteenth-century navigation was still a huge challenge. Few navigators could master the contents of the Regimento. There was no widely accepted north–south baseline against which to gauge distances east or west. There were no seaworthy chronometers and nothing approaching an odometer or speedometer. Quadrants and astrolabes, which depended on a stable gravity vector to stay vertical, were ill-suited to rough open seas. The compass needle had to be periodically remagnetized.

  And the problems didn’t end there. Mariners suspected magnetic variation but had no reliable means of isolating it, so they fiddled with the findings of their compasses in unhelpful ways. Without international standards of measurement, they used conflicting units of the mile, league, stade, and degree, so they ended up assigning varying equivalents to the distances noted in ancient literature. Their old-fashioned planar maritime charts suffered not only from a lack of up-to-date information but also from a disregard for Earth’s roundness. That roundness produces a (then mysterious) convergence of meridians as you approach the Poles, which means that heading sixty leagues east along the equator will take you to a different meridian than if you headed sixty leagues east along the Tropic of Cancer. Yet as late as the late seventeenth century, a navigator could rely on a plane chart, lose his ship, and nonetheless become a Fellow of the Royal Society.43

  As for matters of hunger and health, a well-stocked expedition might carry enough pickled pork, salt fish, ship’s biscuit, cheese, onions, and dried beans to fill the seamen’s stomachs, and enough wine to give each man a liter and a half a day, but the casks of water soon turned foul, and scurvy took a heavy toll.44

  Despite all the handicaps, with every voyage Portugal’s mariners and travelers added to empirical knowledge of what lay where in the western and eastern oceans, and what was seen when in the sky both above and below the equator. With every passing year, their findings and narratives revealed more errors in the maps and coordinates accompanying the much-read Latin translation of Ptolemy’s second-century AD Greek Geographike that had come out in the first decade of the fifteenth century, and each round of errors triggered another round of updated maps and geographical treatises.

  At the respectable age of forty-one, having already sailed the Atlantic as far north as Iceland and as far south as Ghana,45 Christopher Columbus headed west from the Canary Islands on August 3, 1492, expecting that he and his fleet of three ships would come upon Japan within several weeks, at a distance of some four thousand kilometers, and would subsequently reach the fabled Indies. The monarchs of Portugal, Spain, France, and England, and likely also the city-states of Genoa and Venice, had all turned down his proposition at least once. But after having second, third, and fourth thoughts on the matter, and after convening a group of experts—who saw that Columbus had used the wrong version of the mile to calculate the circumference of the round Earth, and had therefore come up with the wrong distance to his destination—Isabella I and Ferdinand II, already the rulers of Castile, León, Aragon, Majorca, Minorca, Sardinia, Sicily, and elsewhere, finally gave him the go-ahead “to discover and subdue some Islands and Continent in the ocean” on their behalf.46

  That Columbus and his three-boat crew of ninety were not the first Europeans to cross the Atlantic does not diminish the ambitiousness of their agenda, the extent of their navigational challenges, or the magnitude of their eventual impact—no matter the errors of calculation or the failure to reach their intended destination. Nearly every man aboard was a seaman; none were soldiers, and weapons were few. Although he later complained that “neither reason, nor mathematics, nor maps were of any use to me,” Columbus had consulted maps, charts, globes, books, and instruments, especially the compass. He read Marco Polo’s Travels and the soon-to-be Pope Pius II’s Historia rerum ubique gestarum, based on Ptolemy’s Geography. He read and copied a June 1474 letter to the king of Portugal from the Italian cosmographer Paolo dal Pozzo Toscanelli, who declared that the shortest way to get from Lisbon to China was to head west, across a nearly empty Atlantic, rather than to go around Africa, and that the distance in a straight line was nearly one-third the circumference of the Earth. He and perhaps his honored cartographer brother Bartholomew read and extensively annotated Pierre d’Ailly’s cosmography Imago Mundi. Like many people of their time, whether learned or merely literate, they both almost certainly read the hugely popular Travels of Sir John Mandeville, a mid-fourteenth-century mishmash of fact, fiction, and faith. They studied recent world maps that suggested the possibility of heading west to arrive at the East. Bartholomew’s own maps of the late 1480s, in fact, show that the brothers may have altered and invented a more attractive geography so as to more effectively persuade their royal patrons to fund the Indies expedition.47

  Columbus consulted aids to reconnaissance willingly. The masters and pilots of his ships would have resisted both reading and calculation; their expertise came from hands-on, hard-won experience maneuvering real vessels within sight of real eastern Atlantic coastlines. Yet even if every man aboard had been a mathematician and literary scholar, of what use were charts, handbooks, and sailing directions in unknown waters? Columbus therefore turned to dead reckoning, the Pole Star, and the compass.48

  Star and compass read differently in different locations, however. Season, time of day, and latitude affect the former; magnetic variation affects the latter, as Columbus found, much to his distress: “The needles declined north-west a full point. In the morning the needles were true. The star appears to change its position, not the needles.”49 Moreover, knowing only the relative “easting” and “northing” would get a navigator (or land surveyor) only so far. If he wished to record exactly where an impassable carpet of seaweed, a luxuriant pearl fishery, or a fortuitous defensive promontory lay, he had to know exactly how far east and north he was—and what he was east and north of. A sophisticated navigator might know how to calculate his craft’s geometric relation to the sky’s salient inhabitants, but to note a position in such a way as to be unambiguously and automatically understo
od, he needed a standard point of reference—two, in fact. He needed coordinates, a grid, a graticule with both an equator and a prime meridian at right angles to it.

  With its main parallel and its prime meridian crossing at the Aegean island of Rhodes, Eratosthenes’s ancient world map had a grid that Hipparchus found arbitrary. Ptolemy’s map, with its prime meridian passing through the westernmost known islands in the Atlantic, had a more astronomically inspired grid. The maps of Columbus’s day—made for scholars and kings, and treated as classified information—had something of a grid, while the marine charts—made for sailors—had none. On the earliest surviving terrestrial globe, Martin Behaim’s “Erdapfel” (“Earth Apple”), completed in 1492, there’s a minimal grid that includes the equator, the tropics, and one meridian.50 When the New World entered the picture, the question of parallels and meridians got messier.

  When grabbing land, who is entitled to what and who gets to decide are not minor issues. For the crowns of Portugal, Spain, and Christendom, the choice of deciders was obvious: themselves. After all, the actual inhabitants of all that attractive New World real estate “lived in perdition of soul and body,” were filled with “great ignorance,” and “had no understanding of good,” so why ask them?51 In 1493 the pope issued the first of a new spate of papal bulls meant to regulate the explorers’ land seizures, giving Spain the lion’s share of everything. Predictably, Portugal was unhappy. As a result, in 1494 Spain and Portugal, both Catholic nations, negotiated and signed the Treaty of Tordesillas, which was reinforced by a papal bull a dozen years later. The treaty fundamentally split the Western world in two: everything east of a north–south line 370 leagues west of the Cape Verde islands would belong to Portugal, and everything west of the line would belong to Spain. In 1529, in the complementary Treaty of Saragossa, the duo split the other side of the world along a line 297.5 leagues or seventeen degrees east of the Moluccas—the so-called Spice Islands, home of the prized clove tree. Portugal ended up with about 191 degrees worth of the world’s girth, and Spain with about 169 degrees. So the conflicts carried on.

  The dividing lines that Spain, Portugal, and the pope adopted had nothing to do with astronomy or mathematics or the science of geography. They were territorial markers, battle lines, private fences, announcements of yours and mine. Neither treaty served up a universal prime meridian. Meanwhile, Iberian expeditions proceeded apace.

  In September 1522 a Portuguese navigator named Juan Sebastián del Cano—who, as part of an expedition of five ships and almost three hundred crew under Ferdinand Magellan’s command, had sailed from the southern Spanish port of Sanlúcar three years earlier—returned to Spain with eighteen men (sans Magellan himself, who had been killed in battle) on the sole surviving ship, the Victoria. Those eighteen had thus completed the first circumnavigation of the globe. Along the way, Magellan’s men inadvertently discovered the international dateline—or rather, they discovered the need for one. Antonio Pigafetta, an Italian nobleman/knight who joined the expedition as a volunteer, served as an occasional diplomat, and kept an account of “all the things that had occurred day by day during our voyage,” described “the mistake of one day which our men discovered” at their last port of call in Portugal before returning home to Spain:

  And we charged our men in the boat that, when they were ashore, they should ask what day it was. They were answered that to the Portuguese it was Thursday, at which they were much amazed, for to us it was Wednesday, and we knew not how we had fallen into error. For every day I, being always in health, had written down each day without any intermission. But, as we were told since, there had been no mistake, for we had always made our voyage westward and had returned to the same place of departure as the sun, wherefore the long voyage had brought the gain of twenty-four hours, as is clearly seen.52

  Three and a half centuries later, the international date line, along with the corresponding prime meridian, would be formally established at the International Meridian Conference in Washington, DC. The date line would be a line running from North Pole to South Pole, crossing the middle of the Pacific Ocean exactly halfway around the world, 180 degrees, from the prime meridian at zero degrees longitude. The prime meridian itself would pass pole-to-pole right through the Royal Observatory Greenwich, near London.

  Though as yet unaffected by prime meridians and missing days, fifteenth-century Portuguese marine charts began to look a little more like maps: while still planar, many show a meridian marked off with latitudes and drawn north–south through Cape St. Vincent, Portugal’s southernmost headland. Soon the maps, if not the charts, would show Earth’s landmasses and coastlines in reasonable proportion and detail. Often the cartography is embellished with references to ownership and allegiance: national flags, coats of arms, religious iconography.53

  Cartography helped conceptualize and display the “theater of the world,” and the stage itself was steadily increasing. A map was the preeminent portable expression of geographical and cosmographical understanding. During the sixteenth century, as noted by the British historical geographer Denis Cosgrove, “the scale and wonder of global diversity—physiographic, climatic, biotic, ethnographic—overwhelmed the European episteme.” Complicit in European oceanic expansion, the map made the case for world citizenship at the same time as it smoothed the way for Western dreams of subjugation and empire. While the cartographer/cosmographer would likely have been a humanist, cosmopolitan scholar who embraced religious tolerance, his Iberian royal patrons would have been bent on aggrandizement and religious hegemony.54

  In 1569 one of those humanists, the Flemish cartographer Gerardus Mercator, produced a world map, a mappa mundi, which he called a “new and augmented description of Earth corrected for the use of navigation,” with meridians, parallels, and sea routes all projected onto a huge rectangle comprising twenty-four separate sheets of paper. Meanwhile, Iberia persevered in its search for cartographical consensus, going so far as to issue questionnaires to its ships’ pilots in hopes of determining the latitudes and longitudes of its New World conquests.55

  In the final decade of the sixteenth century, as ships were being enlarged and redesigned to carry more and heavier gunnery, and their captains were learning to excel in both fighting and navigation, a British mathematician-astronomer-cartographer at Cambridge named Edward Wright applied himself to mastering Mercator’s maps and producing practical charts suitable for seamen.56 Other nation-states followed suit, developing their guns and fleets and cultivating cartographers so that they could dispute Spain’s and Portugal’s claims to territory and amass enough funding to bypass Genoese and Venetian financiers.57 The ships of the Indian Ocean’s traditional navigators could not keep up. By the close of the seventeenth century, Europeans had sailed to, trod upon, confronted the inhabitants of, and extracted products and persons from nearly every landmass on Earth—mapping as they went.

  Astronomy and the natural sciences were indispensable to Europe’s voracious seafaring empire builders. “Eighteenth-century monarchs,” writes historian Joyce E. Chaplin,

  dispatched men of science to the far ends of the earth in order to claim, not only sovereignty over land and sea, but cultural supremacy through the exercise of learning and the gathering of knowledge on the far side of the world. These goals came together perfectly in Captain James Cook’s three voyages into the Pacific Ocean.58

  Funded by Britain’s Royal Society, the first of Cook’s voyages was timed to coincide with a rare event: the 1769 transit of Venus across the face of the Sun, visible only from the South Pacific. One of the biggest scientific unknowns of the day was the physical size of the solar system. Although astronomers had figured out planetary separations in units of Earth–Sun distance, they did not know the Earth–Sun distance itself. But if observers in more than one location, separated by known distances, could precisely time the duration of Venus’s transit, through triangulation they would be able to calculate the distance between Earth and the Sun and thus deduce the dista
nces to all other planets in the solar system.

  The transit made a good top story for the voyage, but it wasn’t Captain Cook’s only directive. After heading for newly discovered Tahiti and setting up an observatory there to monitor the transit, Cook and his crew of eighty-five—plus ten civilians, including four artists and one astronomer59—were to find and chart other islands in the area and, most important, discover Terra Australis Incognita, a mythical continent lurking in the southern reaches of the globe. If they didn’t find Terra Australis, they were to search for and explore other lands instead. In other words, their other job was to augment existing maps.60

  But to what ends?

  Like a calendar, a map—though shaped by scientific thinking—is a statement of political and social power. Writing shortly after World War II, the British historian of navigation E. G. R. Taylor remarked that “during the European wars of the 18th century it was discovered that an accurate map is a weapon of war. And so it remains.” Forty years and several wars later, the British-born historian of cartography J. Brian Harley offered a postmodernist articulation of a similar idea, stressing Foucault’s idea of power-knowledge: “cartography is primarily a form of political discourse concerned with the acquisition and maintenance of power.” David Turnbull pointed out that maps “connect the territory with the social order” and therefore, quoting Pierre Bourdieu, “naturalise the arbitrary.” Novelist Vikram Chandra has also weighed in on the meaning of maps: “A map is a kind of conquest, the precursor to all other conquests. . . . [O]ne kind of knowledge can conceal another. Information nests inside information.”61 And if the “knowledge space” embodied in a map is indispensable to warmakers and other practitioners of power, the map is nearly worthless in peacetime unless its measurements and delineations arise from knowledge that is both shared and internationally binding. For the monarch, the navigator, the admiral, and the general, imperfect cartography was a hazard.

 

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