The Measure of All Things

by Ken Alder

  I have obtained from Citizen Méchain a promise that he will not break off his labor until his triangles are complete and the results sent to you and Borda. It’s all I could do. My family calls me back to Paris, and I cannot stay here until the mission is done. When I left him on the first of this month, the stations of Rodez, Rieupeyroux, and Lagaste were done. Puy St. Georges, Montredon, [Combatjou], and Montalet are, I believe, all that remain. You can currently write to him at Lacaune in the Tarn.

  Citizen Fabre would be glad to grant you the rendezvous that The Measure of All Things you wish to have with him. I hope with all my heart that it takes place. I will urge my husband to join you here.

  I have the honor to be, with the most distinguished sentiments, your fellow citizen,

  Madame Méchain

  She had failed, she said, to convince her husband to join Delambre at Perpignan. She had failed, she said, to stay by his side until his triangles were done. Most tragically, she had failed, she said, to bring him to his senses. Méchain remained bitter and melancholic. Yet she had succeeded—despite her gloomy prognostication—in the central task. News of her impending arrival had shamed him into leaving Carcassonne to meet her at Rodez. And once she arrived at Rodez, she had restored him to his mission. Méchain was triangulating again. Though her name nowhere appears in the expedition logbooks—an invisibility she undoubtedly sought—it is quite likely that husband and wife observed together the angles at the cathedral of Rodez and the chapel of Rieupeyroux, the two stations that linked Méchain’s southern chain with the northern chain of Delambre.

  So did Madame Méchain dissimulate with Delambre? Did she hide, even from him, her role in her husband’s revival? It cannot have been easy for her to work behind her husband’s back, in league with men he considered his persecutors. She told Delambre that Méchain had refused to come to Perpignan because of Tranchot. And Méchain, when he wrote to Delambre, told him much the same story. But in his letters to his friends in Carcassonne, Méchain suggested that this was not the entire truth. Méchain considered the Perpignan baseline “his.” To join his colleague there now, he said, would be to submit himself to “the authority and supervision of Citizen Delambre.”

  For his part, Delambre promised Madame Méchain that he would bring her husband back to Paris, come what may.

  The International Conference was to begin two months hence and Méchain had five stations left to measure, which was just about possible. At the Puy de Combatjou site, he observed from a fertile hilltop, then as now under cultivation. At the Montredon site, he observed from a ruined castle all overgrown with trees, now a lover’s lane for teenagers. At Puy Saint-Georges, he observed from the ruins of a medieval abbey, with its freestanding Gothic arches that still open onto the empty air—although a quaint orientation table placed on the site in 1907 thoughtfully directs your attention toward Paris (535 kilometers), Tokyo (14,050 kilometers), Madagascar (9,285 kilometers), and New York (7,350 kilometers).

  Three stations down, two to go. All well and good, except that it was already mid-September, the savants had begun to arrive in Paris, and the two remaining stations—Montalet and Saint-Pons—were located in the rough Montagnes Noires of Languedoc, where “malevolent persons” had pulled down the signals Tranchot had erected the previous year. All through the season he had been doing battle with the locals and the weather. One signal had been sawn off, another burned to the ground, another dismantled for nails, another toppled by storms. In one town, a village joker told the peasants that a nearby signal was a new kind of guillotine, so the peasants tore that one down, too. Even some local officials seemed to fear that the signals might serve as a secret aid to the Republic’s enemies. For his part, Méchain said, he feared the “fanaticism” of the people.

  His fears were not groundless. Thirty-five years before, a young cartographer working for Cassini III had been surveying from a church tower in the Montagnes Noires, not fifty miles away, when he had been hauled down from his ladder and all but hacked to death by a crowd who claimed that his “sorcery” was sowing death among the villagers. He managed to escape, blood streaming from his head and hands, but the town officials were too intimidated to help him, as were the few strangers he met on the road. Only at nightfall did he manage to stagger into a neighboring town and find asylum in an inn run by the widow Jullia, where a doctor and surgeon tended his wounds. This story was well known to all geodesers and illustrated, sadly, a continuing hazard of the job. It was not so much that the young cartographer was a sorcerer, but that his sorcery was the sorcery of numbers. When surveyors came to measure the earth, peasants had reason to be fearful. In the judicial investigation into the attack, one villager explained that the cartographer was “a sorcerer who had come to harm them and was the agent of taxes, and had come to increase the income tax, ruining them, and causing them to die of hunger.” The court obliged the village to pay reparations and sent the ringleaders to prison. Local priests were told to command their flocks to leave cartographers in peace. But suspicion persisted. And the rough countryside, long famous for its bandits, now sheltered many new fugitives: refractory priests, unrepentant royalists, army deserters, draft dodgers, and rebels of all sorts, all reviled as bandits.

  They are still there. This is the country of José Bové, the present-day peasant-activist with the walrus moustache whose rebellion against globalization has become world famous. Bové lives on the eastern slopes of the Montagnes Noires. He grabbed the attention of the international media when he arrived in Seattle for the 1999 World Trade Organization talks bearing a smelly package of his hometown Roquefort cheese, banned in America in retaliation for the European ban on hormone-treated beef. Bové was already notorious in France for bulldozing a local McDonald’s because its standardized food—la malbouffe—was an affront to his region’s produce. That particular “McDo,” since rebuilt, is the world’s most famous, and certainly the most charming I have ever seen, with glossy wooden tables, packs of happy children, leather-clad teens on cell phones, and a soothing view over a bucolic valley. Yet Bové’s message stands: it is standards that define what we eat and who we are. Standards may not make us identical, but they set the menu for our permissible differences. Bové and his cronies pulled up surveyors’ stakes and bulldozed that McDonald’s for much the same reasons that peasants in the 1790s pulled down Méchain’s geodetic signals.

  As an agent of progress in this region, Méchain was obliged to call on official protection to ensure his safety. After local ruffians tore down his signal at Montalet for the fourth time, he asked that a garrison of militia post a seven-man guard at the site. The jagged Roc de Montalet rises from the pine forests like a shattered cathedral. Blueberry thickets grow at its perimeter. A plaque there commemorates Méchain’s visit, and proudly records his troubles with the locals. Méchain spent ten days at Montalet, sleeping in a tent at the edge of the rock and scratching out daily letters, his fingers numb with cold. Behind his armed guard, he had slipped back into a dark melancholy. He poured out his soul on the page. “I renounce it all,” he told his friends in Carcassonne, “and the instant I complete my assignment I will abandon everything to seek, if I can find it, some refuge of obscurity and peace, the sole balm my lacerated and broken soul can bear.” He feared he was losing his mind. How do you measure the world when the earth is turning beneath your feet? As he told Delambre, “I have spent all my time in the cruelest anxiety, unable to concentrate on what I am doing, continually reproaching myself for the past because the present is unbearable and because I tremble for the future.”

  At the time, Delambre was waiting on the other side of the Montagnes Noires, no more than sixty miles away as the crow flies. He had arrived in Perpignan with his team in late July to prepare the baseline. Tranchot was of great assistance here, having laid the markers along the Grande Route back in 1796 and having already gauged the distance with a surveyor’s chain. The Grande Route ran just to the west of an ancient Roman road, the Domitia, which two thousan
d years ago had served as Hannibal’s invasion route. It had been shifted slightly by the medieval Catalan rulers of Perpignan. Then in the middle of the eighteenth century the Ancien Régime engineers had transformed it into one of the king’s magnificent highways, laying it straight and true from Perpignan to Salses, between dry vineyards on the left and the salt lagoon on the right. And just as Delambre arrived the Republican engineers had begun reinforcing the road in anticipation of heavier traffic. In another hundred years, modern engineers would pave it with macadam and then asphalt. Today, it is known as the N9 and it still runs straight and true, except where it swerves to accommodate a shopping mall.

  Geodesy may be a natural science, one which measures the size and shape of the earth, but it is also a science which depends on human history and human works. To measure a baseline for their triangles, the geodesers needed a straight stretch of terrain, and what could be straighter than a Roman road, adjusted by medieval surveyors, rectified by Ancien Régime engineers, and finalized by rational Republicans?

  On August 6 Delambre, Tranchot, Bellet, and Pommard laid the first ruler. Because they could not afford overnight guards for the rulers (they were, after all, made of the world’s most valuable metal), Delambre had retrieved Méchain’s carriage from storage to ferry the equipment and the team to and from the work site every day. Their goal was the fortress of Salses, an impregnable ochre bastion which blended into the stony red terrain. An English traveler had called this “the most barren country on earth.” Suffocating heat alternated with the winds of the sirocco. The rulers had to be shielded from the sun to prevent them from overheating, lest they expand. Fiery gusts of desiccated air pushed them out of alignment. A flash rainstorm forced the savants to take shelter. Then, toward evening on the thirty-sixth day, a pack of wild dogs charged their camp and scattered the rulers, overturning an entire day’s work. While his assistants labored in the angry sun, Delambre sat in the shaded carriage, reworking the calculations. He had to correct for deficiencies in the thermometers on Rulers 1 and 2, for a slight kink in the road line, for the bridge over the Agly River, and for the forty-eight-foot increase in elevation from one terminus to the other. The price of precision is continual vigilance.

  The southern baseline took two days longer to survey than the northern baseline. But the results corroborated one another to a remarkable degree—proof, the savants said, of the care with which they had been measured. On September 19, the tedious operation completed, Tranchot and Bellet began packing the instruments into Méchain’s carriage for their return to Paris. “Only one obstacle holds me back in spite of myself . . . ,” Delambre wrote, “Méchain.”

  Lalande had predicted as much. “Our poor Méchain cannot finish,” he wrote to Delambre, “and it is up to you to repair the damage done by his illness, or else two months from now we will be no further along than we were last year.” With the conference about to begin, there was no time to spare their colleague’s feelings. Lalande told Delambre to take over and complete Méchain’s triangles for him. “You keep telling me you don’t want to distress him, but when you deny he is ill it’s as if some nut case were to go around denying that you were an astronomer.”

  It was true. Méchain seemed to have taken the only honorable course for a savant who had failed in a mission whose purpose was perfection. He had had a nervous breakdown. His letters had become inchoate, inconsistent, obsessive. Every day he offered another reason why he had yet to finish, why he could not come down from the mountains, why he refused to return to Paris—ever. “The truth is,” he wrote, “that anyone who does not have cause to shed tears for the loss of those dear to them, fearing the loss of their own life and liberty, could hardly be sorry to leave this theater of misery, except for those sick souls who crowd around the guillotine.”

  Delambre traveled to Narbonne, then to Carcassonne, to be as near his colleague as possible. The signal at Saint-Pons, Méchain’s final observation point, was a remote mountain station, an arduous three-hour trek up from the ancient abbey town of the same name. But it was only a day’s ride away. Delambre offered to come and assist his colleague with his measurements if he so desired. He could be by his side by evening.

  By return post, Méchain warned Delambre to stay away. Delambre should not waste his time coming to Saint-Pons when the foreign savants were waiting for him in Paris. “As it is,” he said, “there is barely enough time for you to make the journey in good time. I will send you my results there as soon as I am done.”

  Delambre neither returned to Paris nor charged up the mountain to finish the triangles. Instead he politely requested that the two men meet. He would wait for his colleague to finish, he said.

  He was working as fast as he could, Méchain replied. “But I cannot see through clouds, nor stand up to hurricanes that carry everything before them.” He had arrived at the Saint-Pons station in early October, and taken lodgings in the abandoned Moulinet manor house, a half-hour walk to his signal. Moulinet had belonged to the archbishopric before the Revolution. The setting is spectacular. The mountain slopes are densely forested: fallen leaves form a moist October bed around the mossy rocks. Fox, deer, and wild boar flash through the woods. When the view is clear you can see a fourth of territorial France from the peak: from the ragged blue-and-white bands of the Pyrénées to the south, to the black-and-green ridges of Auvergne to the north. It would be a lovely place to make one’s hermitage, if the affairs of the world allowed it.

  The days slipped by: ten days, twenty days, thirty days, forty days. . . . Still Delambre persisted. He persisted when Méchain promised on October 4 to send all his data the next day, and was still sending summaries a week later. He persisted when Méchain promised on October 13 to finish tomorrow, and then wrote on October 19 to say he was still wrapping up. He persisted when Méchain wrote on October 22 to say he would be in Carcassonne the day after tomorrow, and then again on October 28 to say the muleteer had canceled the trip because a three-day storm had flooded the roads. He persisted, although the foreign savants were waiting and their French hosts had their reputations on the line. He persisted because Méchain had the data without which a definitive meter was impossible.

  Méchain was running out of excuses. “It would be an infinite pleasure to meet you,” he wrote, “though I should fear the occasion.” He kept advising Delambre to leave. You are missing your moment of glory, he reminded his colleague, your chance to present the fruits of your seven-year labor. Which was why, in the end, Méchain had to come down. He could risk his own reputation, but he could not risk Delambre’s, not when Delambre seemed so willing to risk his own moment of glory just to ensure that Méchain shared it. Delambre had let Méchain complete his mission alone—and in that sense, they had done it together. It was a remarkable act of friendship. Delambre’s restraint brought Méchain down the mountain.

  They met in Carcassonne in early November 1798 at the home of Gabriel Fabre, the criminal-court judge whose motto came from Seneca: “A suffering man is a sacred being.” In Fabre’s view, there was no man who deserved his fate less than Pierre-François-André Méchain, “but it does not always lie within us to master our feelings.” And Méchain was certainly a man of feeling.

  For three arduous days, Delambre labored to convince his colleague to return with him to Paris. Méchain tried every evasion. “I am unshaken in my resolve not to return to Paris this winter,” he said. He had repeated this as many times, in as many ways as he could think of. “I will not change my resolution for anything in the world.” He came up with half a dozen alternatives. He might spend the winter in Rodez collecting more latitude data. He could seclude himself in a mountain hermitage and polish up his calculations. “In the springtime, we will see if my existence is still of some use somewhere.” Perhaps he would return to Barcelona to verify his latitude data. Nor had he given up on the idea of extending his triangles as far as the Balearic Islands. To his Carcassonne friends he admitted that he now regretted turning down the job offers fr
om abroad, and that he might yet “seek his fortune elsewhere.” Under no condition would he return to Paris. What kind of greeting could he expect there except “reproaches, disdain, and contempt”? His shameful behavior was already public knowledge throughout France; must it now be paraded before all the savants of the world? “I will not expose myself to this final humiliation,” he said. Let Tranchot take all the credit. (He now referred to his former assistant as “my director.”) He would accept any punishment the Academy doled out. He deserved no less. As for his family, his return could only aggravate their problems, “burdened as I am with myself.”

  Yet once he had come down the mountain, what choice did he really have? Delambre would not return without the southern data, Méchain would not let go of his data, and Méchain could not allow Delambre to delay his own departure any longer. Ergo: Méchain had to go.

  If the meter was a social convention, then the social conventions would have to be observed. If two savants had been sent on a mission to measure the world, then two savants must return—together. Science is a collective enterprise: its highest achievement is to “make a contribution.” If Delambre wanted to claim his contribution, he needed to let Méchain make his. He needed to bring Méchain back to Paris with him—along with his data. Delambre also had one final card up his sleeve, and on the third day he played it. He showed Méchain a letter from the Bureau of Longitudes importuning him to return and promising him the directorship of the Observatory when he got back.

  They left in early November. Delambre had waited fifty days in all.

  Although they had lied about Méchain’s date of departure from Paris, there was no way to disguise the date of his return. The foreign savants had been waiting for two months. It was Lalande who trumpeted the news to his colleagues on November 14. He had just received a message by mail: Delambre and Méchain had arrived at the d’Assy country home in Bruyères-le-Châtel. Tomorrow they would be in the capital. The last triangle had been closed.