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Inaugurated during the French Revolution and rescinded during the French First Empire, the metric system has gone on in the past two centuries to be readopted by France and embraced by every other nation on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 useful 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?


I’m no fan of our legislators’



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 slated 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?

These questions all came to the fore at the first international geodetic conference, held that very year in Berlin. The geodesers in attendance knew better than anyone the shortcomings of the original determination of the meter. Since Delambre had published the final volume of the Base in 1810, his scientific successors had further refined their knowledge of the earth’s shape. Each passing decade had widened the gap between the Archive Meter and the known size of the earth.

During the past half-century, moreover, each European nation had triangulated its own territory, mapping its terrain with reference to the regular ellipsoid that best represented the earth’s curvature through its own particular lands. It was as if each European nation inhabited its own eccentric planet. Some of these nations, Prussia first and foremost, were now eager to fit their maps snugly together with those of their immediate neighbors. For this they needed a common standard and uniform procedures. The Germans suggested a technique for doing this: Gauss’ method of least squares, by which the triangles of every nation could be brought into optimal alignment. In 1861 General Johann Jakob Baeyer of the Prussian army, longtime director of its cartography department, had secured permission to establish a Central European Geodetic Association in Berlin. As he noted, “By its very nature, such an enterprise cannot be the work of a single state; but what one [nation] cannot realize alone, many may achieve together. And if in the process Central Europe should unite for this purpose, devoting all its might and resources, a great and important work will be called into being.”

It was an alarming and exhilarating call, reminiscent of nothing so much as the calls for European unity that had come out of Revolutionary France seven decades earlier. The geodesers were determined to bring their numbers into alignment: to live, as it were, on the same planet. Their association became the nucleus of the world’s first international scientific association.

But when the Germans sent out invitations to expand the association from Central Europe to the entire continent, the French response was divided. Some scientists saw it as a chance to revitalize French geodesy, which was still using the seventy-year-old techniques of Delambre and Méchain. Others saw it as an attempt to subordinate France’s triangles to a pan-European grid and to subvert the one true Archive Meter as determined by Delambre and Méchain, whose results ought only to be revised “with caution and intelligence.” The French government refused to send delegates to the Berlin convention. Relations between the two continental powers were deteriorating rapidly and the French did not want their meter publicly impugned. When one French scientist rashly suggested that the Academy launch its own preemptive expedition to remeasure the earth—and get it right this time—his colleagues quickly shut him up. A standard was fixed, or it was not a standard.

The international geodesers understood this. At the meeting in Berlin, General Baeyer and the rest of Europe’s geodesers agreed that the meter should remain the standard of length—not because it was based on nature, but because it was widely accepted. If the natural origin of the meter was a fiction, it was a useful fiction. “In truth, the meter draws a good deal of its prestige from the notion, flattering to human pride, that our daily measures are drawn from the dimensions of the globe we inhabit.” They insisted, however, that the Archive Meter was defective, and that a new meter bar be made to replace it.

For the previous seventy years, nations adopting the metric system had been obliged to beg France to calibrate their weights and measures for them. This gave France an unseemly custodial power, and the bar itself had been worn down by the continual comparisons. In 1837 a Bavarian scientist found that the ends of the bar were scratched. In 1864 a microscopic inspection revealed that the surface there was pitted. Moreover, chemists had discovered that the platinum, once considered “pure,” was actually adulterated with allied metals (such as iridium), complicating the bar’s rate of expansion with temperature. In sum, there was reason to fear that the bar’s length had altered since 1799, could not be accurately described now, and would change in the future. Nothing, it turned out, was more ephemeral than yesterday’s cutting-edge science. The geodesers of 1867 agreed that the new bar should differ “as little as possible” from the Archive Meter. But they also wanted a permanent international agency to take charge of this new standard so that no one nation could claim the standard for itself.

This sent the French into a paroxysm of self-doubt. Would Germanic precision supplant French precision, as Germany was supplanting France? It was as if the entire nation had taken its cue from Méchain, making his error collective, and his paranoia general. Some French scientists, notably at the Bureau of Longitudes, welcomed the chance to put the metric standard on a secure footing, but the Minister of Commerce rejected any move to replace the meter. And scientists at the Observatory and the Academy concurred. The Archive Meter was in excellent shape, they reported, and remained the only possible standard. Indeed, they went so far as to deny that their Revolutionary forebears had ever claimed that the meter should be based on nature at all, or that all meridians were the same length, or that the length of the Paris meridian might be measured definitively. Thus they thrice denied the founding premises of the metric system. Yet they concluded that they would rather invite their foreign colleagues to Paris than see them establish a rival system.

So seventy years after Napoleon I promoted the first international scientific conference, Emperor Napoleon III, his nephew, sent out invitations for a second metric conference to be held in Paris. This time, scientists from all the world’s nations—including the Americans, the British, and the Germans—were invited. “Today, as in the distant days of the great International Commission of Weights and Measures, it is by inviting French and foreign savants to work together in complete equality that we may best preserve the metric system’s universality and obtain truly international models, perfectly identical with those in the French Archives and capable of serving the scientific needs of each nation, while preparing the world for the general adoption of the metric system.”

In July 1870, two weeks before the conference was to start, Prussia and France went to war. The German delegates stayed home, but scientists from fifteen other nations, including the United States and Britain, held their first assembly in Paris on August 8. At the time, the French army was falling back on Metz. Under the circumstances everyone agreed that any final determinations would have to wait until all their colleagues were present. Then the French brought into the open the question that haunted their scientific nightmares: did their guests really expect to base the new meter on the size of the earth? It took several days for the German-born Swiss delegate Adolph Hirsch (a co-organizer of the Berlin geodesy conference) to reassure his French colleagues that “no serious scientist in our day and age” would contemplate a meter deduced from the size of the earth. The new meter bar would be built to match the old one.

The Prussian army won the war; the French emperor abdicated; the Prussian king became emperor of Germany; and France (after ghastly bloodshed) became a republic again. The French lost Alsace and Lorraine, but they regained democracy. In 1872 the new French Republic reissued invitations for an international metric conference. The German Empire sent several delegates. Wilhelm Foerster, their chief representative, was an affable enthusiast for world metrical harmony. For nearly a month, scientists from thirty European and American nations discussed the form, content, and distribution of the replacement measure. It was all very collegial. They agreed that the new bar should be made as similar to the old one as possible, right down to its impurities: a mix of 90 percent platinum and 10 percent iridium. They also resolved to make as many standard meters as there were nations, and only then to select one to serve as the definitive standard: a first among equals. Finally, they proposed a permanent International Bureau to superintend these activities.

The “Convention of the Meter” of 1875 remains the framework for all international metric standards, including those for electricity, temperature, and other phenomena. Although the French delegates were not keen on a permanent International Bureau of Weights and Measures, they offered to house the institution in Paris rather than see it wrested away by Berlin. The Pavillon de Breteuil, which they donated for its headquarters, had been almost completely destroyed during the recent Prussian siege of Paris and was rebuilt at international expense.



In the 1870s scientists at the workshop of the Conservatoire National des Arts et Métiers in Paris experimented with the construction of a new standard meter. The new definitive meter was not completed until the late 1880s. (From Illustration [16 May 1874], 316; photograph by Roman Stansberry)

It would take fifteen years of scientific controversy—including a spat over the platinum-iridium alloy that nearly caused another Franco-German rift—to construct new meters to the Bureau’s specifications. By then virtually every European nation had mandated gradual introduction of the metric system. When the bars were shipped out in 1889, the old Archive Meter, built to match the meridian data collected by Delambre and Méchain, lost its universal status and fell, like the Châtelet toise before it, into the pit of history. It became just another stick of precious metal, worth the market price for platinum, plus whatever value human memory ascribed to it. But, needless to say, the French government did not melt it down. They preserved it, as before, in the National Archives, a historical artifact like any other, to be read as evidence of the past.

Delambre and Méchain, the myth now went, had heroically measured the earth so that the meter could be set at one ten-millionth of the quarter meridian. Their error was forgotten, even as the embodiment of their error was preserved. It was preserved in 1889 when the new platinum-iridium bar replaced the old Archive Meter. It was preserved again in 1960 when the International Bureau redefined the meter in terms of the wavelength of light emitted by a specific energy transition in the krypton-86 atom. And it was preserved again in 1983 when the Bureau redefined the meter as the distance traveled by light in a vacuum in 1/299,792,458 seconds (with time, the fundamental unit, now defined by an atomic clock). Thus, the new quantum mechanics, famous for its principle of measurement uncertainty, has again provided the Bureau with a standard based on nature that can be specified with exceeding (but never final) precision. Yet each redefinition, including the most recent, has been concocted so as to preserve the length of Delambre and Méchain’s original meter of 1799.

The truth belongs to everyone and no one. It is public property and ephemeral, or else it is not the kind of truth we call science. But error is forever because, having happened once, it exists, like an unhappy family, in its own particular way. Delambre and Méchain built their lives into the meter: they traveled the meridian, they selected its stations (including their own private sites: the country château at Bruyères, the observatory on the rue de Paradis), they peered through the scopes, and their inky fingers calculated the angles of the earth and the stars. The meter is their epitaph because only a person’s mistakes are truly his own. Yet in accepting their meter, we have made their error our own, which is to say public, singular, and true. Theirs was truly an error for all people, for all time.


By the middle of the twentieth century, the vast majority of the world’s nations—with the major exceptions of the British Commonwealth and the United States—had joined the metric system. Each time, the precipitating event was political upheaval. Shortly after it became a republic in 1912, China announced that it would switch to the metric system during the next decade; the law was enforced after the revolution of 1949. Tsarist Russia recognized the metric system in the late nineteenth century, but it was the Soviet Union that in 1922 made metric measures mandatory. Despite earlier legislation, Japan and Korea did not seriously convert to the metric system until after World War II. The system spread through Asia and Africa in the wake of colonization, and later in the wake of decolonization; either way, metric uniformity appealed to those who wished to legitimate their territorial rule and create a national administration, even as they opened up their territory to extranational market forces. Thus Jawaharlal Nehru took India metric soon after the British left in 1947. And the more the metric system spread, the more irresistible became the logic of joining the world’s preeminent international network.

Britain was the first economic power to adopt the metric system without passing through radical political upheaval first. No doubt this explains why it was also the last. The Victorians had concentrated on unifying their imperial measures, itself a daunting task. By the mid-nineteenth century they had largely eradicated local variations and anthropometric measures, so they had little incentive to switch from their traditional physical standard in London to a different “natural” one in Paris. An antimetric lobby complained of the costs, confusion, and resentment that would accompany conversion. Above all, they scorned the metric reformers as elitists, and presented themselves as practical men—always good politics, especially when they could claim to be anti-French to boot. The scientific eminence John F. W. Herschel dragged Méchain’s secret error into the public eye and charged him with “disingenuous concealment” in the affair of the Barcelona latitudes. If Britain really insisted on a measure based upon nature, Herschel suggested, it should adopt the length of the earth’s axis from pole to pole. As this distance just so happened to equal 500,500,000 inches it would provide a natural basis for the British Imperial inch. Thus, with a little British ingenuity, everything could be brought thoroughly up to date—without changing anything at all. The engineer William Rankine attacked the metric reformers with this ditty.

A party of astronomers went measuring the earth,

And forty million metres they took to be its girth;

Five hundred million inches, though, go through from pole to pole;

So let’s stick to inches, feet and yards, and the good old three-foot rule.

Not until 1965, on the eve of its decision to join the European Common Market, did the British government announce a ten-year transition to the metric system. More than thirty years have elapsed, and the “harmonizing” process drags on—as do the protests. On January 1, 2000, a new era dawned in Britain: shopkeepers were obliged to sell in metric units. A few months later, Steve Thoburn, a Sunderland grocer who sold bananas by the pound, had his scales confiscated. The tabloids worked themselves into a frenzy of indignation. This is the sort of local resistance that has everywhere accompanied the introduction of the meter. The British conversion may involve a simple translation from one set of impersonal measures to another; yet even this degree of disorientation can feellike a loss of sovereignty. And in a sense, Britain’s long-delayed adoption of the metric system was precipitated by a loss of sovereignty: the decline of the Commonwealth, and Britain’s entry into the European Community.

Once Britain committed itself to conversion, the rest of the Commonwealth countries followed suit. In 1970 Canada announced that it would not wait upon its huge trading partner to the south. A voluntary transformation was envisaged, coaxed along by an educational campaign, with animated films such as Ten: The Magic Number. As consumer goods in metric units proliferated (toothpaste first), some Canadians protested. But generally Canadians have been puzzled by their own “sheepish” willingness to accept the meter—to the point where they have come to consider it a point of national pride that their country has gone metric while America has not.


Americans have been arguing about the metric system since shortly after the signing of the U.S. Constitution. Article 1, section 8 granted Congress authority “to fix the Standard of Weights and Measures.” Who would have thought so quantitative and banal a subject would elicit such passion? Industrialists and scientists, mystics and nativists, curmudgeons and enthusiasts, schoolteachers and politicians have all battled over the world’s measure. To date, America’s metric advocates have always failed.

Paradoxically, it is America’s modernity—its freedom from “feudal” institutions, its origin in colonial rule, and hence the relative uniformity of its measures—that explains the country’s failure to switch to the ultramodern metric system. As a large and homogeneous economy, the United States already enjoys most of the coordination advantages that come from common standards, reducing its incentive to join the rest of the metric world. And even though doing so would undoubtedly bring long-term economic gains, the American government is notoriously beholden to business groups and populists, who insist on short-term payback. America is the only country in the world that still thinks it can afford to stay outside the metric system even as it participates in the world economy.

Not until the 1830s did the United States even define a national standard. A Swiss geodeser named Ferdinand Rudolph Hassler, who had arrived in the United States in 1805 bearing one of the definitive iron meters of the International Commission, became the first director of the National Bureau of Standards. He affirmed the decision to stick with the English weights and measures. In 1863, within a month of its founding, the National Academy of Sciences began pressing for the metric system. Yet Congress was content merely to legalize the metric system and allow Americans to adopt the new measures voluntarily—an approach that remains U.S. government policy to this day. America, in Jefferson’s terms, has preferred to mold the law to its citizens, rather than its citizens to the law—at least where commercial interests are at stake.

In America, as elsewhere, even the prospect of the metric system has provoked a nativist response. The humorist Josh Billings mocked the International Metric Convention as a harbinger of universal standardization. “Never,” he wrote, “did so many Kaisers, Kzars, Kings, kum kling knit together in so Klean a Kawse to work so Kommendable a kure.” Others considered the metric system an abomination. Charles Latimer was a devout Christian, a successful railway engineer, and an avid pyramidologist who believed that the “sacred inch” had been built into the Great Pyramid at Giza and had been transmitted across the millennia to the United States. He also had a visceral contempt for atheism, the French, and the metric system. He would even have preferred a Statue of Liberty “measured in good earth-commensurable Anglo-Saxon inches, not in French milli-meters.” No doubt, the antimetric arguments of U.S. industrialists and engineers did more to dissuade Congress in the long run. But Latimer could plausibly boast that he had stopped Congress from passing metric legislation in the 1870s and 1880s.

The most recent U.S. campaign to adopt the meter began in the 1970s, when it became clear that the United States would be the last major metric holdout. In 1971 the National Bureau of Standards issued a report entitled A Metric America: A Decision Whose Time Has Come without even the courtesy of a question mark. Efficiency gains and international trade, it argued, made metric conversion well worth the short-term costs to consumers, manufacturers, and government agencies. Multinational corporations wanted to assemble goods from parts made in all corners of the globe. Certain industries—alcohol and automobiles—had already adopted the metric system. But when the 1975 Metric Conversion Act emerged from Congress it lacked enforcement powers, financial wherewithal, or a timetable for conversion. As President Gerald Ford memorably announced at the signing ceremony: when it comes to the metric system, U.S. industry “is miles ahead of official policy.”



Late in life the Franco-American artist Marcel Duchamp referred to this piece, usually translated as “Three Standard Stoppages,” as “a joke about the meter.” It was also his investigation into the relationship between universal standards and individual creativity, as well as a seminal moment in the inauguration of art made from found objects. The piece was begun in 1913-14, when Duchamp “dropped” a piece of thread one meter long from a height of one meter onto a wooden slat and preserved the resulting curvy shape by painting the string over with varnish. For each of the three repetitions of this “experiment” he then cut a wooden template to match the curvy shape. These he later placed one above the other, eventually adding vertical and horizontal straightedge rulers labeled “1 METRE” to document his procedure. The assembled piece was not completed until 1953, when it was displayed at the Museum of Modern Art in New York. In the intervening decades Duchamp deployed the curvy wooden templates as his own personal standard to design a series of other artworks. According to the artist, this was his first attempt to use “chance as a medium”; yet closer examination shows that he did not drop the threads at all, but in fact carefully arranged them on the wooden slats. There are many ways to read this fascinating piece. It subverts the ideal of exact measurement even as it demonstrates the role of universal standards in the creation of the most personal and idiosyncratic art. It may suggest the “stoppage” of the guillotine. (From the Museum of Modern Art, New York; © 2002 Artists Rights Society (ARS), New York/ ADAGP, Paris/Estate of Marcel Duchamp; photograph by Art Resource)

And so it has remained. Official attempts to convert freeway signs to kilometers have only riled the citizenry. Newspaper editorials mock metric advocates as petty dictators, or worse, boring. Chicago Tribune columnist Bob Greene founded WAM! (We Ain’t Metric!): “WAM’s guidelines are eloquent and simple: We are against the metric system because we don’t like it. We won’t learn it because we don’t want to.” President Reagan disbanded the Metric Board. A 1992 follow-up pamphlet from the National Bureau of Standards, A Metric America: A Decision Whose Time Has Come—For Real, had the ring of desperation. Gallup polls showed that, as awareness of the metric system doubled between 1971 and 1991 (from 38 to 80 percent), the number of those who wanted the U.S. to adopt the system dropped by half (from 50 to 26 percent). It was a trend that would have made Condorcet weep.

The kilometer signs have come down and gas is again being pumped in gallons, now that the service stations have added a digit to the left of the decimal point to keep track of the dollars. But America keeps rolling silently toward the metric system. Its car parts are sized in metric units. So are its bicycles. It is no longer enough for American exporters simply to label their products in both American and metric units (soft metric); trade groups abroad are demanding that goods be delivered in even metric units (hard metric).

Oddly, as more Americans are lured into using the metric system, it may be that the nation will lose the very uniformity of weights and measures that has long made the metric system seem unnecessary in the United States. The most spectacular fatality of this new mixture was the crash of the Mars Climate Orbiter in 1999. Has the time come for America to join the metric globe at last?

No doubt the world economy would operate with greater efficiency if we all spoke the same language; yet the world would be impoverished by the loss of the diversity this represents. Foreigners often complain—and the French complain vociferously—that America is currently spearheading a capitalist globalization that is leveling all the differences that make life worth living. Well, in this instance it is America that is different. This book has demonstrated that measures are social conventions, the outcome of a political process. Many Americans already use the metric system in domains where the economy operates on a global scale, as do many (but not all) engineers, physicians, scientists, and other technical professionals. These people are already metrically “bilingual,” which is, in its own way, a good thing. But Americans have shown little willingness to give up their traditional measures in their daily lives. Sooner or later it will seem time for Americans to give up their old units, not because the rest of the world uses the metric system, but because America does.

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