America’s Old Resistance to Metric Measures May Be Inching to an End : Standards: Uniform units began with the French. Over centuries, uses in the United States have become mixed.

“Let them eat cake,” was the alleged reply of French monarch Marie Antoinette upon learning that the people had no bread. Her words helped to spark the French Revolution of 1789 and, believe it or not, to usher in the age of the metric system.

In Marie Antoinette’s time, French cake and pastries were made from sugar and flour sold in portions similar to English pounds and ounces. With the revolution, the new French government adopted a new system of weights and measures--using meters, liters and grams. Ms. Antoinette, who was put to the guillotine in 1793, never swallowed cake made from ingredients measured out in metric units.

Today, 200 years after its introduction, the United States is the only industrialized nation in the world which has yet to adopt the metric system. Japan, Germany, Sweden, Spain, Great Britain and Mexico converted long ago.

“Americans are still debating the merits of the metric system,” says Dr. Peggy Kidwell, specialist in mathematics at the Smithsonian’s National Museum of American History in Washington. Kidwell phrases the debate simply: “Does the metric system represent genuine progress, or will adopting it be a bothersome, expensive departure from customary practice?”

As recently as the 1970s, Kidwell says, a major campaign was launched to encourage Americans to switch systems. Fearing a disadvantage in international trade, the U.S. Congress endorsed the metric standards. “The American public was reluctant to abandon its familiar weights and measures,” Kidwell says. “And not for the first time.” In fact, rejection of the metric system seems to be something of an American tradition.

As early as 1790, Thomas Jefferson proposed that the United States adopt a new system of weights and measures. In 1795, a French government decree on the metric system was published in the United States. It was largely ignored.

“At the time,” Kidwell says, “the most powerful people in the country were of English origin and they tended to favor units familiar to them.” By 1821, weights and measures based on English units had been adopted by the states.

Some people find America’s refusal to “go metric” ironic in that the system was largely democratic in its conception.

“In pre-revolutionary France,” Kidwell explains, “units of measure differed from place to place far more than in England or the English Colonies of America. Local nobility controlled the size of measures, such as the bushel.

“Peasants, who paid rent in bushels of grain, wanted a fixed, national unit of measure because they believed the bushel kept getting bigger. French merchants also sought uniform weights and measures for trade.” During the French Revolution, peasants rallied to the cry, “One king, one law, one measure!”

After the French Revolution, a commission from the Paris Academy of Sciences developed an ingenious system of measuring distance, volume, weight, and angles and even time.

“I don’t think the masses who had demanded a standard system during the revolution had any idea that the change would be as radical as it was,” Kidwell says. “The basis of the new system was not familiar dimension, like the length of a human foot. The new unit of distance, the meter, was one-ten-millionth of the length of a quarter of a great circle that passed through Paris and the North Pole.

“Metric units were also interconnected,” Kidwell continues, “for example, units of one quantity, such as length, increased by powers of 10, such as centimeters, decimeters, meters. The liter was the volume of a cube 10 centimeters on a side. One kilogram was the weight of one liter of water,” Kidwell explains.

“No such simple relations exist in English weights and measures among units of length (inches, feet, yards, miles) or between units of length, volume and weight. In short, the French not only introduced national standards, but an entire system of standards. This system survives today, in modified form.”

The designers of the metric system did not stop with weights and measures. Ten-hour metric days were also introduced. Hours were divided decimally, too, but France soon returned to the 60-minute hour and 24-hour day.

Americans stuck with their English units through the 19th Century rather than adopt a system developed, as mathematician Charles Davies put it, “amid the turbulence of a revolution by a committee of learned professors.”

A major push for the metric system in the United States came in the 1860s, spearheaded by Assistant Postmaster John Kasson. The Post Office was losing money through a complex of fees required to establish rates for overseas mail. Kasson and postal officials from several other countries agreed to a system of standard rates, with mail weighed in metric units. By 1866, metric units also were legal for trade--though not required--in the United States.

Several distinguished Americans--including Joseph Henry, the first head of the Smithsonian Institution, F.A.P. Barnard, president of Columbia University, and librarian Melvil Dewey--established the American Metric Bureau in Boston and the American Metrological Society in New York to promote the metric system.

In 1870, however, a special committee convened to consider adopting the metric system concluded that “it would be difficult to teach” and that “Americans would prefer to retain units that had emerged from long practice.”

“Moreover,” Kidwell says, “American engineers were proud of standards they had developed on the shop floor. Some Americans also admired the time-honored English units because they believed that they were linked to measures used in ancient Egypt and perhaps in ancient Israel.”

At the same time, a few American instrument companies began making rules with metric scales and wall charts explaining the metric system. Melvil Dewey, inventor of the Dewey Decimal System, promoted a range of metric teaching devices--charts, length measures, weights, scales and capacity measures. The American public was unswayed.

Over the same period, during the mid-19th Century, a number of European countries adopted the French metric system and it was used increasingly in science, medicine and international mail. In time, it was accepted throughout the world.

In the 1970s, U.S. government officials planned a program of strictly voluntary conversion to the metric system that was to take 10 years. Many Americans disliked the unfamiliar measures and, in the 1980s, President Reagan cut back the funds for metric conversion programs. Meanwhile, metric units had been widely adopted in some industries.

For advocates of the metric system, the cause continues. A congressional act, passed in 1988, designated 1992 as the year the federal government would convert to metric, but a recent survey indicated that the individual bureaus are far from meeting this deadline.

“All science is metric,” says Lorelle Young, president of the U.S. Metric Assn. “If we expect to be world leaders in science and technology we need to teach the metric system to our kids from an early age. Now they don’t learn the metric system until they study hard sciences in junior high and high school.”