Bollocks to the metric system. In fact bollocks to decimals as well.
Did you know the "King's Girth" (within which any violence is an attack on the crown) extends around the monarch's location with a distance of 3 miles, 3 furlongs, 9 acres*, 9 feet, 9 palms and 9 barleycorns.
There's some dispute, however, as to whether this is a radius or a circumference. Given the 22/7 approximation for PI it's probably a radius.
John Quincy Adams wrote, in his report to assist Congress in deciding what system to adopt:
Considered as a whole, the established weights and measures of England are but the ruins of a system, the decays of which have often been repaired with materials adapted neither to the proportion, nor to the principles of the original construction. The metrology of France is a new and complicated machine, formed upon principles of mathematical precision, the adaptation of which to the uses for which it was devised is yet problematical, and abiding, with questionable success, the test of experiment.
To the English system, belong two different units of weight and two corresponding measures of capacity, the natural standard of which is the difference between the specific gravities of wheat and wine. To the French system there is only one unit of weight and one measure of capacity, the natural standard of which is the specific gravity of water.
The French system has the advantage of unity in the weight and the measure, but has no common test of both: its measure gives the weight of water only. The English system has the inconvenience of two weights and two measures, but each measure is, at the same time a weight. Thus the gallon of wheat and the gallon of wine, though of different dimensions, balance each other. A gallon of wheat and a gallon of wine, each weigh eight pounds avoirdupois.
The litre in the French system is a measure for all grains and all liquids; but its capacity gives a weight only for distilled water. As a measure of corn, of wine, or of oil, it gives the space they occupy, but not their weight. Now, as the weight of these articles is quite as important in the estimate of their quantities as the space which they fill, a system which has two standard units for measures of capacity, but of which each measure gives the same weight of the respective articles, is quite as uniform as that which, of any given article, requires two instruments to show its quantity  one to measure the space it fills, and another for its weight. In the difference between the specific gravities of corn and wine, nature has also dictated two standard measures of capacity, each of them equiponderant^{excellent word!} to the same weight.
This diversity existing in nature, the Troy and Avoirdupois weights, and the corn and wine measures of the English system are founded upon it. In England it has existed as long as any recorded existence of man upon the island; but the system did not originate there, neither was Charlemagne the author of it. The weights and measures of Greece and Rome were founded upon it. The Romans had the mina and the libra, the nummulary^{another excellent word!} pound of 12 ounces, and the commercial pound of 16 ounces. The avoirdupois pound came through the Romans from the Greeks, and through them, in all probability, from Egypt. Of this there is internal evidence in the weights themselves, and in the remarkable coincidence between the cubic foot and the 1000 ounces avoirdupois, and between the ounce avoirdupois and the Jewish shekel; and if the shekel of Abraham was the same as that of his descendants, the avoirdupois ounce may, like the cubit have originated before the flood.
The result of these reflections is, that the uniformity of nature for ascertaining the quantities of all substances, both by gravity and by occupied space, is a uniformity of proportion, and not of identity; that instead of one weight and one measure, it requires two units of each, proportioned to each other; and that the original English system of metrology, possessing two such weights and two such measures, is better adapted to the only uniformity applicable to the subject, recognised by nature, than the new French system, which, possessing only one weight and one measure of capacity, identifies weight and measure by only the single article of distilled water, the English uniformity being relative to the things weighed and measured, and the French only to the instruments used for weight and mensuration.
It can be applied, only with many qualifications, to any general system of metrology, that its natural application is only to numbers; and that time, space, gravity and extension inflexibly reject its sway [...] it is doubtful whether the advantage to be obtained by any attempt to apply decimal arithmetic to weights and measures, would ever compensate for the increase of diversity which is the unavoidable consequence of change. Decimal arithmetic is a contrivance of man for computing numbers, and not a property of time, space or matter. Nature has no particularities for the number ten: and the attempt to shackle her freedom with it will forever prove abortive.
... so there!

simon
* probably a chain x furlong acre, therefore 9 chains.
