Depending on your point of view, it is either surreptitious socialism - what one commentator called the creeping 'Brussels-isation' of America - or a belated blow for common sense. Either way, the slow march of metrification continues.
Judging by appearances, you wouldn't think so. For the newcomer from Britain, a country only lately and imperfectly weaned off the Imperial standard, the weights and measures in use here are nostalgic, yet disconcerting. Yes, the pint and the quart are alive and flourishing, while the survival of the gallon at the filling station is profoundly reassuring. But the same gallon of milk or orange juice still seems a wanton extravagance, enough to slake an army's thirst.
Happily, America has stuck to miles (with exceptions like markers on Interstate 19, south of Tucson, close to metrified Mexico). But a warning saying, 'lanes merge at 2,500 feet' induces panic. The figure of 5,280 comes to mind. Wasn't that the number of feet in a mile - or is it acres per square mile, or square yards per acre? But there are compensations, not least the superiority of Fahrenheit, abandoned by the rest of the world.
Zero Celsius is merely chilly; zero Fahrenheit is cold. And while 100 Celsius merely denotes where water boils, 100 Fahrenheit conveys real heat, or fever. Electronic temperature display signs tend to use both measurements, though. The surprise is that the metrifiers have not carried the day long since.
After all, they have been around almost as long as the Republic. Hardly had the French adopted the system at the turn of the 19th century than President Thomas Jefferson, that most rational of men, proposed that America follow suit. The idea was rejected on the grounds it would interfere with trade with Britain. In 1866, however, Congress placed the metric system on equal legal footing with the 'English' system, and in 1893 went further by decreeing that all US weights and measures be defined metrically.
Jimmy Carter learnt that lesson the hard way. Under his presidency there was an official Metrification Board. 'Think Metric' signs briefly appeared along highways, while at least one big oil company, in a fit of misguided idealism, started selling petrol by the litre instead of the gallon. An irritated populace was swift to make the connection. America's fortunes did not boom in the Carter years. The assiduous promotion of that foreign contrivance, the metric system, somehow only added insult to injury.
Ronald Reagan quickly realised that one way to have the country walking tall again was to stop funding the Board. All that remains today is an unassuming Office of Metric Programmes, buried deep inside the Commerce Department. Under a 1988 act, the federal government is still supposed to go over to the metric system: but only 'where feasible' and certainly without fanfare.
A few bold souls did stick to their metric guns, among them the National Geographic magazine. It found that references to kilometres, kilos and litres produced more hate mail than any single issue except evolution. And so matters stand. Only three countries in the world have not gone metric: the US and those two other global powerhouses, Liberia and Myanmar (or Burma).
But quietly, the metric tide advances. It will never be complete - what hamburger chain would dare promote a '112-grammer'? But in other fiercely competitive markets, grams and kilos have long since won the day. Whoever heard of New York drug dealers pushing cocaine by the tenth of an ounce, or the half-dram?
Legitimate importers and exporters, too, have long had to think metric. Consummate politician that Bill Clinton is, he won't risk votes by talking about it.