Leading Article: Prolonging the imperial anguish

The Sunday afternoon pint of shandy in the local pub was short lived. Permitted at last by the relaxation of the licensing laws in August, it was banned again by metrication yesterday. This time the problem is not the alcohol content of shandy, but the fact that it contains lemonade, and so, unlike "traditional" beer, cannot be sold in a pint measure. Sounds absurd, but apart from the odd irritation, most people will hardly have noticed that Britain just stepped up a gear in its transition from imperial to metric measures.

Pounds and ounces are out. Grams and kilos are in. Products must be labelled in metric. They can have imperial labels too, and they don't actually have to change the size of the product they package. So a pound of cheese is fine so long as the label says 454g. Loose food products are still exempt, so are measures that describe a product and so are deeply embedded within our culture: the pint of beer in the pub, the pint of milk on the doorstep, and the 16-inch shirt collar. Eighty per cent of grocery goods already comply with the regulations, so it's hard to see why anyone should complain, other than the Imperial Metrics Preservation Society.

Yet the Federation of Small Businesses and several national newspapers are up in arms. They claim the changes are confusing, unnecessary and costly for retailers. At worst, metrication represents a further loss of British sovereignty in the face of homogenising babble from Brussels bureaucrats. But Eurosceptic passion is aiming at completely the wrong target. The European market is not the only reason for Britain making the change. Metric is easier to use. There are a thousand grams to the kilo, a hundred pence to the pound and 10 fingers to the person.

So why not have both systems of measurement running in tandem? Let those who need familiarity stick with the pounds and ounces they can visualise, and those who need to do lots of adding up use the maths-friendly milligrams, grams, and kilos. Then if the metric measures win in an open competition, no one can complain. The trouble is, that means the worst of both worlds. Confused shoppers can't work out if packaged tomatoes at pounds 1.60 for 750g are better value than the loose cherry variety at 80p/lb. The point about standard weights and measures is to make sure that the marketplace is fair and everyone knows how much they are buying and selling. The most sensible objection to changing from a familiar to a new measuring system is that in the confusion of the conversion, customers are easily conned - but that's all the more reason to get it over and done with, so we can all get used to the new units.

Furlongs, acres, cubits, and stone have all been around a long time. There are 20 fluid ounces in a pint, two pints in a quart, four quarts in a gallon, two gallons in a peck, four pecks in a bushel and 8 bushels in a quarter. There is a strange beauty about such myriad and complex numbers and patterns developed with quirks and hiccups through the centuries. Even so, the real test of a system of weights and measures is its ease of use, not its depth of culture and tradition. No matter how aesthetically pleasing the sixpence, few would wish to return now to pounds, shillings and pence.