The Mapmaker's Wife (11 page)

Voyage to Quito

B
Y EIGHTEENTH-CENTURY STANDARDS
, the
Portefaix
provided La Condamine and the others with pleasant accommodations. Each of the three academy savants had a small private cabin, and while the others had to make do with tiny wooden bunks, they took comfort in knowing that the
Portefaix
, under the able hand of Captain Ricour, was sailing along at a speedy five knots an hour and would reach the West Indies in little more than a month. They ate a steady diet of salted meats, with La Condamine, Bouguer, and Louis Godin dining at the captain’s table, and each night they all enjoyed a nip of the fine brandy they had brought along. Even the weather was cooperative, the moments when their ship was buffeted about by
“large and long waves” interspersed with longer periods of calm.

They also stayed busy with a variety of tasks. From the moment they had put to sea, La Condamine and Bouguer had been compiling navigational logs and conducting experiments, with Jean Godin and the others assisting them. Much of their time was spent studying
the utility of several newly invented navigational instruments, which had been awarded prizes by the French Academy of Sciences, including
“Mr. Amonton’s sea barometer, and the Marquis of Poleni’s machine to measure the wake of a vessel.” Poleni’s invention was designed to improve on standard methods for calculating a ship’s speed, which involved throwing overboard a weighted wooden disk attached to a rope with knots tied at equal distance along its length. By counting the number of knots that reeled out over a given period of time, sailors could get a rough measure of how fast the ship was moving. The problem was that this method did not account for the speed of the current. Poleni’s machine was supposed to remedy this deficiency, but La Condamine’s experiments were inconclusive on whether it accurately did so.

Another instrument that La Condamine and Bouguer tested was John Hadley’s octant for determining latitude at sea. Mariners had long used the simple astrolabe to determine the altitude of the North Star or the sun, which in turn gave them an estimate of their latitude. Other devices, such as the cross-staff and sea quadrant, were employed for this purpose as well. The shortcoming with such instruments, as Bouguer had detailed in a 1729 paper titled “De la methode d’observer exactement sur mer la hauteur des astres,” was that they were used by sailors standing on a heaving deck, which made it difficult to obtain a precise reading of the angular distance between the horizon and a celestial star. Hadley, a member of the Royal Society of London, had invented a novel solution for this problem. His octant employed two mirrors and a sighting telescope in such a manner that if the instrument vibrated for any reason, the instrument and the objects under observation, such as the horizon and the sun, would move as one. The observed angle between horizon and sun would thus remain the same. His invention, which he had presented to the Royal Society in 1731, was designed to
“be of Use, where the Motion of the Objects, or any Circumstance occasioning an Unsteadiness in the common Instruments, renders the Observations difficult or uncertain.” Louis Godin had brought the octant back from his instrument-gathering
trip to London, and as the
Portefaix
sailed across the Atlantic, Bouguer and La Condamine tested its usefulness by measuring the height of the sun each day at noon. With the octant, they found that they could chart the movement of the sun so closely that they could identify the moment, to within fifteen seconds, when it reached its highest point. This, La Condamine noted, was
“far beyond the usual limits, which previously did not allow for being certain of midday at sea by closer than two minutes.” Hadley’s invention apparently produced an eightfold improvement in accuracy. Captain Ricour could now be confident that his latitude measurements were accurate to within a couple of miles.

With their minds occupied in this way, the days passed quickly. Even Bouguer found that putting Hadley’s octant to the test and the other experiments had helped him forget his natural “repugnance” for sea travel. The one unsettling moment of the voyage came when Jussieu, the expedition’s botanist, was bitten by a dog that the mission’s doctor, Senièrgues, had brought aboard. Although Jussieu was not badly hurt, Senièrgues decided that the dog needed to be killed. This so upset the sentimental Jussieu that he hid for days below deck in his bunk with the curtain drawn, refusing all entreaties to come out.

They arrived in Martinique in the West Indies late in the afternoon of June 22, 1735, docking at Fort Royal. They had traveled more than 4,000 miles in thirty-seven days, and now they delighted at the sight of the volcano Mount Pelée, its slopes thick with tropical vegetation. This was a gentle introduction to the New World, for Martinique could provide many of the amenities of home. Although Columbus had sighted the island in 1493, naming it Martinica in honor of Saint Martin, the Spanish had never settled it, leaving the door open for a French trading company to claim it in 1635. The French brought in slaves to work sugar plantations and rapidly pushed the native Carib Indians into the far corners of the island. As part of a 1660 treaty, the Caribs agreed to reside only on the Atlantic side, but that peace was short-lived, and soon the Caribs who were not killed in battle fled the island altogether.

La Condamine and the others stayed ten days on Martinique, buying supplies and lugging their barometer up the slopes of Mount Pelée to an altitude of
“700 toises above sea level,” where they found the cold, even in the tropics, “severe.”
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They were intent on using the barometer to measure altitude in the Andes, and in order to do so, they needed to improve their understanding of how the instrument could be used for this purpose. The barometer had been invented a century earlier by an Italian, Evangelista Torricelli, who had shown that weather-related changes in air pressure caused water in a thirty-five-foot-tall vacuum tube to rise or fall. By replacing water with mercury, which was fourteen times heavier, Torricelli was able to create a barometer less than three feet tall, a size that made his new invention portable. Wealthy people in the late seventeenth century proudly displayed this weather instrument in their homes. However, in 1648, France’s Blaise Pascal observed that air pressure also dropped as one climbed in altitude. Mercury levels in a barometer dropped about one inch for every 1,000 feet gained, but this change in pressure was not precisely linear: The drop in the mercury level grew ever so slightly less pronounced as one climbed higher. What Bouguer hoped to do on this voyage was develop a logarithmic scale that would describe this variable change in air pressure, and Martinique provided an ideal laboratory to launch the effort. He and La Condamine took the barometer to different spots on Mount Pelée and, with the sea visible, they were able to
“determine their heights geometrically.” They then correlated their altitude to the barometric readings, a first step toward creating the desired logarithm.

Their next stop was Saint Domingue, a French territory on the island of Hispaniola. They departed from Martinique on July 4, with La Condamine recovering from a mild case of the “illness of Siam,” or yellow fever. One of their guides in Martinique had come down with symptoms of the disease on July 2, and a day later La Condamine began exhibiting them as well. A dreaded sickness in
the New World, the illness of Siam’s initial fever and vomiting often gave way to seizures, coma, and death. But Senièrgues and Jussieu treated La Condamine with “all haste,” and he revived so quickly that he later recounted that he was
“ill, bled, purged, cured and placed on board within 24 hours.”

Hispaniola had been the first island colonized by Spain, and so it was a sore point with Spain that France had wrested control of its western third in 1697. French pirates had long hidden in the coves and bays on this part of the island, harassing Spanish shipping at every turn, and in 1697, with the decrepit King Charles II slowly dying in Madrid, Spain reluctantly signed the Treaty of Ryswick relinquishing the western region. The
Portefaix
anchored on July 11 at Fort Saint Louis, on the southern coast, and then sailed around a spit of land to Petit Goave. There the French visitors lodged in a small inn and waited for permission to proceed, a wait
that quickly turned frustrating. The governor of the French colony wrote his counterpart in Santo Domingo, asking that he send a ship to take the French academicians to Cartagena, but the Spanish governor wrote back to say that he was unable, at the moment, to provide such transport.
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Time was passing, and what unsettled the French academicians, even though they did not want to admit it, was that they knew they were in a race.

Shortly before they had departed from La Rochelle, Maupertuis had proposed to the academy that he lead a second arc-measuring mission, this one to Lapland. By sending expeditions to both Lapland and the equator, Maupertuis had argued, the academy could be assured a more definitive answer about the earth’s shape. Rather than comparing the length of an arc at the equator to that of one in France, the academy would be able to compare arcs measured at the two extremes of the earth, which would greatly lessen the possibility that an imprecise measurement would lead to a misleading result. While this was good science, it was disturbing to those heading to Peru. The group that came back first, they knew, would most likely gain fame for having solved the great question.

As the French and Spanish diplomats exchanged letters, the French scientists occupied themselves as best they could. They determined the longitude and latitude of various forts and towns on the island, and Verguin drew several maps. La Condamine also hired a merchant to make two large tents with awnings, each a copy of the largest tent they had brought with them from La Rochelle. He was tending to a delicate matter, for if they had only one large tent, a question would arise over which of the three academicians would get it. By commissioning two more, he ensured that each would now have his own sleeping quarters. The others in the crew would share three smaller tents, befitting their lower status as assistants.

Even so, as the party lingered in Saint Domingue, tensions surfaced between Godin, Bouguer, and La Condamine. Each had his
own ideas about how the expedition should be run, and to make matters worse, Godin, with idle time on his hands, took up with a local woman. Gregarious as always, he delighted in strutting about town with her, which did not endear him to the local populace, and he showered her with gifts. This upset La Condamine and Bouguer, for it meant he was piddling away the expedition’s cash. The three exchanged sharp words on more than one occasion, causing Godin to remind everyone that
he
was both the senior member of the academy and the expedition’s leader. By early October, even the mild-mannered Jussieu was irritated with Godin, deriding him in a letter home as a
“youngbeard without experience.”

Six hundred miles away, two young Spanish military officers in Cartagena—Antonio de Ulloa and Jorge Juan y Santacilia—were similarly growing impatient, wondering if the “French academicians” they were supposed to keep an eye on would ever arrive.

A
T FIRST GLANCE
, Ulloa and Juan did not appear to be very well suited for the task at hand. They were so young—Ulloa was nineteen and Juan twenty-two—that it seemed certain they would be easily intimidated by the French savants, who were not only older but of much higher status. Yet, as would become evident in the months ahead, King Philip V had chosen wisely. Both Ulloa and Juan were well educated, firm in their resolve, and intellectually curious.

Ulloa, a native of Seville, was the son of a well-known economist, Bernardo de Ulloa. As a child, Antonio was small and sickly, and his father constantly worried that he would never amount to much. When Ulloa turned thirteen, his father decided that the only education that could save his son from mediocrity was harsh experience, and so he asked the commander of Spain’s trans-Atlantic fleet, Manuel Pintado, to take him on as a cabin boy. This was an unusual position for a wellborn boy, and yet no schooling could have offered Ulloa more. The experience both steeled his character and fired his imagination. In 1733, he entered the Spanish naval
academy, the Royal Academy of Midshipmen, where he became a member of an elite company, the Guardias Marinas. There he was taught mathematics, astronomy, and navigation.

Juan’s early childhood had also been difficult. Born into a noble family in Valencia, he was orphaned at age three, at which time he went to live with an uncle. He was tutored at home until he was twelve; then he was sent to a boarding school in Malta, where he showed such an aptitude for mathematics that the other students nicknamed him Euclid. At age sixteen, he decided upon a naval career, and like Ulloa, was admitted into the Guardias Marinas. King Philip V promoted them both to the rank of lieutenant for the mission to Peru.

They had reached Cartagena on July 9, 1735, having had the good fortune to travel from Spain in the company of the new viceroy of Peru, José de Mendoza, the Marqués de Villagarcía. Although they were eager for the French to arrive, they had plenty to do. In addition to chaperoning the French visitors, Ulloa and Juan had been asked by Philip V to prepare a thorough report on Peru, and they had taken this responsibility to heart, filling their notebooks with engaging accounts of Cartagena’s history and daily life.