The Measure of All Things

by Ken Alder

  CHAPTER TWELVE

  The Metered Globe

  I know no harm of Bonaparte, and plenty of the Squire,

  And for to fight the Frenchman I did not much desire;

  But I did bash their baggonets because they came arrayed

  To straighten out the crooked road an English drunkard made. . . .

  —G. K. CHESTERTON, “The Rolling English Road”

  The origins of measures, we may presume, go back to the dawn of human history. Well, not quite the dawn. According to Josephus, the Jewish historian of antiquity, the origins of measurement go back to Cain. This degenerate son of Adam not only killed his own brother, he was the first land surveyor and city planner. Then to round out his sins “he put an end to that simplicity in which men lived before, by the invention of weights and measures.”

  Measures are a consequence of man’s fall, a human invention for a world outside Eden, where scarcity and mistrust rule, and labor and exchange are our lot. Measures are more than a creation of society, they create society. As the outcome of years of negotiations over the proper way to conduct exchanges, their ongoing use reaffirms our social bonds and defines our sense of fair dealing.

  Inaugurated during the French Revolution and rescinded during the French First Empire, the metric system has gone on in the past two centuries to be readopted by France and embraced by every other nation on earth—except the United States, Myanmar, and Liberia. In 1821 John Quincy Adams (the son of a different Adam) was asked to report on whether the United States should adopt the metric system. Adams had made a close study of Delambre’s Base and he greatly admired the meridian expedition. He declared that the International Commission of 1799 had marked a new epoch in human history, pointing toward a future in which “the metre will surround the globe in use as well as in multiplied extension; and one language of weights and measures will be spoken from the equator to the poles.” Adams’ prediction has been borne out. A system spurned in its homeland has become the world’s measure—though not in Adams’ homeland. How did this happen?

  Its advocates have called the triumph of the metric system inevitable, and this aura of inevitability has always been their most compelling argument. If everyone else is going metric, there is a huge incentive to join the crowd. This, however, begs the question of how its advocates managed to convince the world that the metric system was inevitable. As late as the 1950s, visitors to a science museum in Paris were warned that the Anglo-Saxon measures were about to “implant themselves” in France. How was the world convinced that the metric system would triumph?

  To outward appearances, the spread of the metric system has tended to follow upon political upheaval, at least as a matter of law. The metric system was first legally adopted in France during the Revolution, imposed on Western Europe during the French First Empire, adopted by the newly unified nations of nineteenth-century Europe as a sign of their sovereignty, and then pressed upon their colonies by administrators from the mother countries. At the same time, the actual on-the-ground implementation of the metric system has taken a much more gradual course, tracking lumbering social developments in education, manufacturing, trade, transportation, state bureaucracy, and professional interests. From the beginning, Adams anticipated it would be thus. A change in metrical standards, he warned, was “one of the most arduous exercises of legislative authority.” Writing the legislation was easy, “but the difficulties of carrying it into execution are always great, and have often proved insuperable.” Yet even this process of gradual implementation depended essentially on political will. Only sovereign states had the authority to coordinate so far-reaching a transformation in the lives of their citizens. And unless the change were coordinated there was little point in converting. When Adams wrote to Thomas Jefferson to ask him for his views, the former president, who had long given up hope of metric reform, put his finger on the essential dilemma: “On the subject of weights and measures, you will have, at its threshold, to encounter the question on which Solon and Lycurgus acted differently. Shall we mold our citizens to the law, or the law to our citizens?”

  But if standards are a matter of political will as much as of economic or technical readiness, then reaching an agreement on standards depends as much on myths as on science, especially on myths about science. It was an open secret among nineteenth-century astronomers that Méchain had obtained contradictory results for the latitude of Barcelona. And any scientist who looked in a table of physical constants could see that the Archive Meter fell a hair short of one ten-millionth of the distance from the North Pole to the equator. These two flaws were not, in fact, connected. The meter was flawed because the expedition’s governing premise was flawed—the premise that the French sector of the meridian measured by Delambre and Méchain in 1792-99 could be considered representative of the world’s shape as a whole. Scientific progress had falsified the meter, as Lalande had hoped it would. Yet in spite of this, Delambre and Méchain’s epic mission succeeded—not because it had produced accurate results, but because it was epic.

  Ultimately, the restoration of the metric system in nineteenth-century France depended as much on scientific piety as on the promised reign of reason, as much on the grandeur of the past as on the allure of the future. But past and future could not meet in the present until the French Revolution (and its metric revolution) had reclaimed an honored place in French history. The Revolution of 1830, which deposed the Bourbons and inaugurated the “bourgeois monarchy” of Louis-Philippe, made such a present possible. In 1837 the government revived the metric system, both as a promise to modernize France and a public assertion that the new régime was a worthy successor to the first great Revolution. The two men who did the most to promote the legislation had similarly mixed motives. One was Charles-Emile Laplace, the physicist’s son, who had inherited his father’s title and sat in the House of Peers. The other was Claude-Louis Mathieu, Delambre’s scientific executor, now a representative in the House of Deputies. Their argument was simple: the metric system would make France a modern, prosperous nation in the years to come, and it could be implemented immediately, thanks to the glorious achievements of France’s past.

  The story of Delambre and Méchain’s mission played a prominent role in this political campaign. Their exactitude in the face of social chaos exemplified what was noble and salvageable from the first great Revolution. Their comical troubles with the common people—those benighted folk who had accused them of espionage and sorcery—implied that the people’s rejection of the metric system had been based on a similar misunderstanding. Above all, their meridian expedition had been a monumental undertaking, a celebrated piece of France’s Revolutionary legacy that must be preserved. In this sense, the meridian expedition succeeded as a matter of politics, even if it had failed as a matter of science. The great virtue of the meridian expedition, it now turned out, was that it could not easily be repeated—as a simple pendulum experiment might have been. The meridian expedition, by its very grandeur, difficulty, and expense, had fixed the meter—permanently. The same meridian project that had scuttled international cooperation in the 1790s by alienating Thomas Jefferson and the British savants now made the meter impervious to change. The expedition had removed the meter from the flux of scientific progress and locked it away in the National Archives as a platinum fact.

  The legislation, which was passed with overwhelming support in 1837, made the metric system obligatory throughout France and its colonies as of January 1, 1840. France had elected to mold its citizens to the law. When one representative—a prominent physicist, as it turned out—asked that the law permit units divisible by eight as well as ten, so as to help those who sorted goods by halves and quarters, an anonymous deputy shouted back from the floor, “On the contrary, we must break their bad habits.” For some, this metric victory signaled the final repudiation of the Ancien Régime, both in the workplace and in the halls of power.

  Challenging routine and hatred,

  Taking its stand on u
seful things,

  The measure of the Republic

  Has overthrown the foot of kings.

  But what one person dismisses as routine or habit, another calls a livelihood. While the legislature deliberated in Paris, a riot broke out in Clamecy, a small riverside town in Burgundy on the banks of a new canal connecting the Loire to the Seine. Dockworkers smashed decimal measures, and the government had to call in the cavalry. The dissension had been sparked less by the new measures per se than by the suspicion that the transition would come at the dockworkers’ expense and open the town to ruinous competition. A plaintive song began making the rounds in 1840:

  What’s it good for, this new law?

  From this day forth can we no more

  Order a pound of yellow tallow,

  Nor butter by the quart?

  Will every corner grocery

  Hire a staff of sorcerers?

  Or will the Paris Academy

  Supply us with our stockboys?

  CHORUS:

  I’m no fan of our legislators’

  Decimal

  Systemical.

  Long live the measures of yesteryear!

  And damn the new weights and measures!

  Fifty years later, a priest in Corrèze, a region along Delambre’s sector of the meridian, could still complain that the metric system was unknown there. In 1900, in the area surrounding Amiens, Delambre’s hometown, many citizens still used the old measures to measure cloth. In the 1920s land in the south of France was still parceled out in units which varied from district to district depending on the quality of the soil.

  By then, however, the world of the old measures was dying. Across the decades of the nineteenth century, knowledge of the metric system had radiated out from schools, cities, and railway lines. As provincial and foreign immigrants poured into the cities, their children acquired a public education sponsored by the central state. As towns became important markets for the countryside, farmers packaged their produce accordingly. Rural France found itself being lured out of the village marketplace and into the world of the market principle. World War I was the turning point, in metrical matters as in so much else. The younger generation stopped speaking the various local patois; now they spoke only French. In the decades that followed, electrification reached the farms, along with government subsidies. Full conversion took nearly two centuries, but today the metric system feels as natural throughout France as the old measures once did. In the process, the thinking of the French people has also changed.

  Everyone in France is now “enlightened.” They accept the metric system as the only possible system of weights and measures, and are barely aware that there has ever been any other. In market towns, grocers will still sell you a livre (a pound) of beans. This is no longer a local variant, however, but simply the popular name for 500 grams (though tourists are still advised to watch for a surreptitious thumb on the scale). Today’s French citizens are much wealthier than their ancestors. More educated. More numerate. More calculating. The young people are all leaving for the cities. Local distinctiveness is receding into the distance. The metric system is all they will ever know.

  Yet France was not the first country to convert to the new measures. By the time France restored the metric system in 1840, it had already been obligatory for two decades in Holland, Belgium, and Luxembourg. This was a consequence of the French First Empire—and of its defeat. The diversity of measures in the Low Countries had long frustrated administrators there. After France annexed those territories they shared her metric régime—and her populist revolt. The collapse of the Napoleonic Empire threatened complete metrical chaos. The people of the Low Countries may have resented French rule, but the restored monarchy saw the advantages of its centralized form of administration, especially for a fractious territory that thrived on commerce. King William I of Orange ordered the decimal metric system obligatory throughout the Low Countries by 1820. And when Belgium separated from Holland in 1830 it not only retained the metric system, but reverted to the original nomenclature.

  Thus the metric system simultaneously became a tool of political unification at a national level and facilitated the sort of international commerce that would—in the long run anyway—dilute national sovereignty. Italy is a good example of how this pattern played out. The French armies had forced the peninsula into larger political groupings, ruled metrically by the iron meter rulers that the Italian savants brought back from the International Conference. The French retreat disrupted a reform that had met with little popular success. But once the French resurrected the metric system in the nineteenth century, Piedmont and Sardinia quickly declared the metric system obligatory as of 1850. Over the next decade other Italian city-states joined the bandwagon. This embrace of a common system of measures pointed toward the creation of an Italian nation-state—which likewise took place in incremental stages between 1861 and 1870, and which declared the metric system the sole national standard in 1863.

  The Spanish case shows how the metric system united not only nations, but those nations’ colonies and their successor states around the world. Spain had been among the first nations invited to join the metric system. After all, the meridian arc had one foot in Catalonia. That invitation was declined. A Spanish law of 1849, which set the metric deadline for 1852, was extended half a dozen times. In 1852 Portugal likewise called for a ten-year transition, a deadline likewise extended. In the meantime, however, the metric system was legally adopted throughout the newly independent states of Latin America. Decrees in favor of adopting the metric system were passed in Chile (1848), Colombia (1853), Ecuador (1856), Mexico (1857), Brazil (1862), Peru (1862), and Argentina (1863). Each of these laws had to be reiterated on many occasions, and the local populations retained their old measures for many years, but these laws gave the metric system the aura of inevitability, which was always its greatest asset.

  So far, legal enactment of the metric system had followed in the wake of revolution and war. In each case, the impetus came from an upstart régime seeking to legitimize its rule. Yet the popular adoption of the metric system followed a quite different pattern: it accompanied the expansion of networks of education, transportation, and trade, together with the spread of a money economy. By the middle of the nineteenth century, there were those who wanted to press for a coordinated conversion on a global scale.

  It was an era of international commerce and great-power rivalry. Bilateral agreements regulated trade between states, even as alliances divided them. Professional groups reached across national borders, even as nationalism grew more shrill. A worldwide postal treaty signed in Paris in 1863 defined weights of international parcels in metric grams. The globe was striped by time zones and stitched together with undersea telegraph cables. Statisticians convened international meetings—at Brussels (1853), Paris (1855), London (1860), Berlin (1863), Florence (1867), and the Hague (1869)—to insist that their respective governments adopt the French metric system.

  The virtues of international standards of weights and measures were first showcased for the general public in London, at the spectacular Crystal Palace Exhibition of 1851. The judges there complained that they could not pick the prizewinners fairly because the entries were presented in thousands of incommensurable weights and measures. Some concluded that the best solution lay in one of the exhibits, a set of metric standards submitted by the Paris Conservatoire des Arts et Métiers. At the Paris World’s Fair of 1867 visitors could walk through a glass-and-iron pavilion and gape at the diversity of the world’s measures, culminating in the metric standards. A guidebook pointed visitors toward the obvious conclusion.

  Suddenly, the utopian dream seemed within reach. In the 1860s Britain, the United States, and the German states all appeared to be on the verge of joining the metric bandwagon. In 1863 the House of Commons passed, by a vote of 110 to 75, a law mandating the metric system throughout the British empire. The parliamentary session ended before the House of Lords could act, but a new vote was s
lated for the next year. In 1866 the United States Congress voted to make the metric system legal—though not obligatory. America’s metric advocates expected to win full conversion in the next session of Congress. And in 1868 the German Zollverein—the Prussian-led customs union that laid the groundwork for German unification—agreed to require the metric system as of January 1, 1872.

  For France, this was a momentous opportunity—with commensurate risks. Eager as they were to welcome the world’s great economic powers to their metric network, the French feared that these nations would dictate the terms of their entry in such a way as to invalidate the original standards. Having argued so passionately that the fundamental unit must be based on nature, the French now feared being hoist by their own rhetoric.

  The pivotal test came from Germany, France’s alarming new rival. The metric system appealed to the various German states for the same reasons it appealed to the Italians. It was just as the French savants had foretold: the metric system was acceptable to everyone because it favored no one. Prussia wanted to unify all the German states under its rule. The Prussian state may have been militarily and administratively potent, but it wanted the rich, industrialized states of western Germany to agree to unification willingly. In 1861, when Austria (Prussia’s rival) conferred with those western states on common weights and measures, the Prussians refused to join the discussions. But by 1867, when Prussia had won the upper hand against Austria, it could afford to behave more magnanimously. Prussia agreed not to impose its own measures, and instead to adopt the metric system as a natural, neutral standard sanctioned by science.

  But was the metric system neutral or was it French? Was it natural or historical? Was it sanctioned by science or by law? Was it derived from the size of the earth or was it just a corrupt platinum bar housed in the Paris Archives?