The Measure of All Things

by Ken Alder

  CHAPTER NINE

  The Empire of Science

  The most magnificent prizes are reserved

  For those whom mathematics serve.

  For triangles connected at enormous cost,

  Never to be renounced, whether true or false.

  . . . . . . . . . . . . . . . . . . . . . . . . . .

  Have they decreed new weights and measures?

  Subjected old folks to the latest tortures?

  To hoist a pint, or cut a yard of cloth,

  Or adjust the hands on the family clock

  Was the arc of the meridian really worth it?

  We can cut our fabric without measuring the earth;

  And if our calculations are not free of error,

  To break old habits is still false rigor.

  —LOUIS SÉBASTIEN MERCIER, Satires on Astronomers, 1803

  Méchain returned to a hero’s welcome. He scarcely had time to clean himself up before he and Delambre were ushered in to a formal banquet hosted by the President of the Directory, the Minister of the Interior, the Minister of Foreign Affairs, and the entire Academy of Sciences, all of whom were lined up to offer their collective (if belated) greetings to their prodigal expedition leaders and the visiting savants, obliging Méchain to accept their heartfelt congratulations, “which they presumed I deserved,” he remarked, “for the completion of my mission.” It almost pained him to admit it, but his colleagues even offered him “a demonstration of their most tender friendship, expressing satisfaction with the accomplishments of the past and confidence for the future.” And this was not all. In the days that followed, they confirmed his elevation to the directorship of the Observatory, the highest honor in French astronomy. They elected him temporary president of the Bureau of Longitudes. They crowned his head so high with laurels that he dared not look behind him.

  “The first days are always glorious and festive,” Méchain confided to his friends in Carcassonne. “Those that follow will be the days of trial. . . . Will I then be able to fulfill the expectations for which they honor me now?”

  In his absence, Paris had changed. If its buildings were recognizable, their inner purpose had been reconsecrated. The same might be said for its inhabitants. The Panthéon had become a national mausoleum; the old nobility had given way to a new notability; and the Méchain family had moved out of the little house on the edge of the gardens and into the redecorated Cassini apartments in the main Observatory, where Méchain now ruled in the Cassinis’ place. His children had grown up. His youngest boy had been six when he left; he was now thirteen and wanted to be an astronomer like his father. His oldest son had departed on a geodesic expedition of his own, working as an astronomical aide on Napoleon’s expedition to Egypt. While Méchain had been traveling far from home for seven years, those he had left behind had traveled further still.

  After months of delay, the world’s first international scientific conference could begin. The preeminent savants of all the nations of Western Europe—all those nations, that is, allied to France by conquest or watchful neutrality—had gathered in Paris to settle together the true length of the meter. These were not men who could be easily fooled, and who would try?

  It was Laplace—the most eminent of them all—who had first proposed the conference. It would guarantee, he said, the metric system’s universality. Let the final determination of the meter be set by an International Commission, and it would dissipate any lingering “jealousies” caused by the decision to base the meter on a meridian that ran through France alone. Let the foreign savants consider the metric system their own work, and they would ensure its spread to foreign lands. Privately, of course, Laplace assured Delambre that the gathering was a “mere formality.” As the basic parameters of the metric system had all been set in advance, the foreign savants would come to Paris simply to rubber-stamp the preordained results.

  Not all the French expected their guests to be so docile. Commander Borda, the prime mover behind the meridian expedition, objected to the conference. If the meridian expedition had produced a meter based in nature, why did it need the imprimatur of the savants of all Europe? The truth did not care who spoke on its behalf.

  But Laplace’s proposal found two powerful backers. Minister Talleyrand, the perennial master of French foreign policy, was still committed to metric reform as a tool of international diplomacy, although France was now in a position to command rather than beseech. Where Talleyrand had once proposed that Britain and France cooperate on the new measures, his Foreign Office now invited only savants having “at heart not only the progress of the arts and sciences, but also the glory of the nations prepared to collaborate in this undertaking.” The British were pointedly excluded.

  Laplace’s other ally was the most junior member of the Academy of Sciences. Ordinarily, a young academician would not dare to intervene in such a momentous controversy between his seniors only one month after his election, but Napoleon Bonaparte was an extraordinary academician on several counts. For one thing, he had never published a scientific paper. His main claim to scientific fame was the fact that he had been Laplace’s examination pupil at artillery school. He had no pretensions to original invention or research. Rather, Laplace had advanced his candidacy (over the marvelous Lenoir, among others) in the hope of allying the Academy to France’s rising political star.

  For his part, the general had political ambitions, and science was part of his campaign. He did not merely cultivate the sciences, he cultivated the savants. He returned from his Italian conquests bearing Renaissance art and the latest theorems. He strode into Academy meetings to the applause of men and the cheers of women. He was no wilting Méchain, cowering from praise. In the throng after the meeting, Delambre expressed surprise that the general was back in town again so soon. “I am indeed, and will dine with you tomorrow if you so desire.” Over dinner, he spread his napkin on the table to diagram a new geometric proof from Italy. “My dear General,” fawned Laplace, “we have come to expect everything from you, except a lesson in mathematics.” He was the universal man: blending thought and action, science and romance, inspiration and planning. He was as delighted as a child with his election to the Academy, and intervened immediately in its affairs. An international scientific conference on the meter dovetailed nicely with his own vision of a Europe unified under French leadership.

  Invitations had gone out in June 1798 to savants from the Netherlands, Denmark, Switzerland, Spain, and the Italian republics; those nations, in other words, which would form the nucleus of the League of Armed Neutrality directed against Britain. None of the savants of Britain, America, or the German states was invited.

  From the beginning, the French had expected America—their sister republic—to be the first country to join the metric system. They had been delighted when Jefferson dropped his preference for a pendulum standard at the 38th parallel (near Monticello) in place of a standard at the 45th (near Bangor, Maine), clearing the way for trilateral Franco-British-American cooperation. In 1792 a committee of the United States Senate even recommended this pendulum standard as the national unit of length. But when the French savants switched to a meridian standard that traversed France alone, Jefferson became convinced that the French show of internationalism was a sham. Congress put off any consideration of the legislation.

  The French did not give up so easily on America, however. Soon after the passage of the metric law of 1793, they dispatched the naturalist-explorer Joseph Dombey to convey the new (provisional) standards to the United States in the form of a copper meter stick and a kilogram weight. In January 1794 Dombey set sail from Le Havre on the American vessel The Soon. Unfortunately a storm drove him to the Caribbean, to the fractious French colony of Guadeloupe. From there, his mission went from bad to worse. Local plantation owners imprisoned Dombey as an emissary of the radical Jacobin government. Released upon threat of violence by those loyal to Paris, he disguised himself as a Spanish sailor and boarded a Swedish schooner, only to be capture
d by British corsairs and escorted to the prison island of Montserrat. There he died of illness in April.

  Miraculously, Dombey’s papers and the precious copper meter bar and kilogram weight arrived safely in the United States (where they are still preserved in the Museum of the National Institute of Standards and Technology) and the French ambassador took up Dombey’s mission with enthusiasm. Ambassador Fauchet said he was delighted to learn of the metric reform and expressed his confidence that “an enlightened and free people would receive with pleasure one of the discoveries of the human mind, the most beautiful in theory, and the most useful in application.” By this he meant the French people. He also hoped the adoption of the metric system in America would “cement the political and commercial connexions of the two nations.” His hopes were echoed in newspaper editorials urging all Americans—or at least, all educated Americans—to adopt the rational French measures voluntarily.

  For a time, success seemed within reach. Fauchet was friendly with President Washington, who was friendly toward France, and the President asked Congress to reconsider the metric system. Washington had stressed the great importance of uniform measures in all three of his earliest State of the Union addresses. Although this sort of repetition is almost always a bad omen, Fauchet still held out hope. In a coded letter sent back to Paris, he noted that American adherence to the metric system might well prove advantageous to France. “Would it not make the People here more French if they shared in our knowledge; would it not bind them closer to us with commercial ties if they were subjected to our System of weights and measures?” He did worry, however, that Congress, having learned that the measures were merely “provisional,” would deliberate and delay “as they so like to do.”

  While Congress dithered and America began a diplomatic rapprochement with Britain, Fauchet recklessly supported the Whiskey Rebellion, as a prelude to a great Jacobin revolution in the United States. This infuriated President Washington and prompted Fauchet’s recall to Paris. Six months later the House of Representatives voted to adopt national standards based on a modified version of the English foot and pound. These were not the ordinary foot and pound, but standards fixed by scientific experiment, and divisible into subunits of ten. The Speaker of the House urged passage. So long as each former colony had its own standards of weights and measures, national commerce would remain uncertain. This time, it was the Senate that killed the legislation by inaction.

  Would it have helped if Delambre and Méchain had completed their mission in 1794 as planned, and the meter had been declared “definitive”? Or if Fauchet had been more prudent? It is hard to imagine that anything could have saved Americans from two hundred years of fruitless debate. Jefferson understood this very well. The United States Congress, he acknowledged, was dominated by a mercantile class hostile to France and fearful of surrendering their customary English units. On a question so immediate to their commercial interests, their views would always predominate.

  For its part, the British Crown had been trying to reform its weights and measures for as long as the French, with as little to show for its pains. The Magna Carta’s lofty promise of uniform measures had been buttressed by stern parliamentary decrees and reaffirmed by the Article of Union between Scotland and England, without curbing a diversity as confounding as the languages of Babel. Travelers needed to learn a new language in every parish or market town, one which “no Dictionary will enable us to acquire.” The apothecary, the silversmith, and the wool merchant all spoke distinct measurement dialects. The county of Hampshire alone had three different acres, plus a different bushel in each market town. This diversity produced “cabal, delay, fraud, anxiety, and indeed everything hostile to the good faith and confidence which ought ever to subsist between buyer and seller, agent and principal.” “Knaves and cheats” forced the poor to sell wheat in a large bushel and buy back bread in a small one. Indignant administrators condemned these practices as iniquities—which by the rules of transparent exchange they no doubt were—although the local people undoubtedly considered them integral to the just-price economy, which prevailed in much of Britain as well.

  British men of science, like their Continental brethren, added their voices to the call for uniform measures. Since the days of John Locke and Christopher Wren, members of the Royal Society had proposed standards based on nature, such as a new “yard” defined as a pendulum beating at one-second intervals in the Tower of London (equal to 39.2 inches). And in the eighteenth century the new thinkers called “economists” likewise championed uniform measures as a spur to commerce.

  Then in 1789 an obscure Member of Parliament named Sir John Riggs Miller urged the House of Commons to coordinate its metric reform with the French National Assembly. Miller convinced Talleyrand to allow the pendulum to be measured at a site jointly determined by British and French savants. In Europe’s antique universal language, he expressed this antique universal dream.

  Una fides, pondus, mensura, moneta, fit una,

  Et flatus illaesus totius orbis erit.

  One faith, one weight, one measure, and one coin,

  Would all the world in harmony conjoin.

  The hard part about harmony, of course, is getting everyone to sing in tune. Since almost any standard will do equally well, so long as everybody agrees on it, everybody prefers that someone else make the change. Miller faced this obstacle both at home and abroad. Each of Miller’s learned allies within Britain had his own idiosyncratic view of which standard would be best. And collectively, Parliament expected the French to follow Britain’s lead, especially now that the French embrace of constitutional monarchy would cause them to be “emancipated from national prejudices.”

  So when the French switched to the meridian standard, it killed the enthusiasm of even the most sympathetic British savants. Charles Blagden, Méchain’s collaborator in the 1788 Greenwich–Paris survey, saw the Dunkerque-Barcelona project as a transparent bid to exclude all other countries from any say in the new measure. Once the war broke out, the British press began mocking the metric system as another instance of Republican rationalism run amuck. Miller’s proposal died in Parliament.

  The same problem kept the Germans at home. The patchwork sovereignty of principalities that had multiplied measures in what later became Germany also precluded any centralized solution there. Besides, the German savants likewise preferred a standard based on the pendulum to one based on a meridian whose value, they noted, depended on who conducted the measurements, and where, and with what instruments. It was just this sort of discontent that the international conference was supposed to pacify.

  War kept the British, American, and German savants at home, but France’s victories on the Continent made it impolitic for her neighbors to refuse her invitation. Bonaparte had brought the Italian peninsula under French rule. French occupation had reconstituted the Low Countries as the Batavian Republic. Spain had been forced into a sullen neutrality. Switzerland had been refashioned by the French as the Helvetian Republic. And the left bank of the Rhine had been rechristened the départements réunis, “reunited” to greater France first militarily, then politically, and now cartographically through the geodetic labors of engineer Tranchot.

  With meter sticks and maps, the French would manage an empire, uniting the tools of commerce and military might in the form of a geodetic meter based on the size of the earth. A transnational metric system would mold the European economy into a Continental bloc, while “an army of astronomers,” outfitted with repeating circles, would assimilate all the nations of Europe to a single grid. As Delambre put it: “Now that the use of the repeating circle has spread throughout the Continent, one may hope that all Europe will soon be covered with triangles.” Indeed, the French were determined to extend their new metric revolution right around the globe.

  Bonaparte was not in Paris for the conference he had helped to convene. The modern Alexander the Great—the world conqueror and world civilizer—had left France on the most exotic metric exp
edition of all: the invasion of Egypt. At the core of his force of 54,000 soldiers and sailors was an “academy” of 167 savants, including mathematicians, naturalists, chemists, and geodesers. Their goal was both imperial and geo-scientific: to supplant a British Levant with the French civilizing mission and to reclaim antique civilization with the tools of modern science. Among the savants was the twenty-year-old Jérôme-Isaac Méchain, an astronomical assistant to abbé Nouet, the former monk Méchain had trained at the Observatory. Lenoir’s son had come along, too, to make any repairs needed on the team’s repeating circle. While Méchain the father triangulated his way through the south of France, Méchain the son mapped an empire: from Marseille to Malta to Alexandria, then up the Nile to Cairo. While the father sighted wooden pyramids in the Montagnes Noires, the son triangulated the Great Pyramid at Giza. While the father agonized in his monastic retreat at Saint-Pons, the son struck out with an expeditionary force for the fount of all scientific knowledge.

  In the summer of 1799, a team of Napoleon’s savants headed up the Nile to Syène (Aswan), famous, as the expedition leader noted, for “its proximity to the Tropic of Cancer and the measurement of the earth conducted by Eratosthenes.” There, on the island of Philae, where the cataracts of the Nile poured from red granite cliffs, the savants carved their global position on the wall of the Temple of Isis:

  R. F.

  AN 7

  LONGIT. DEPUIS PARIS, 30°34'16"

  LATITUDE BOREALE, 24°1'34"