First of all, the litre is not an SI unit. So, its value is not vitally important. The SI unit of volume is the cubic metre.
Second, More recently, the definition was changed back, and 1 L does equal 0.001 m^3 Third, the kilogram is not defined as a litre of water, but is defined by the prototype cylinder in Paris. Fourth, the relation of 1 L = 1 kg, is only true under certain ideal conditions. One of them being a temperature of 4�C. For all practical applications the elegance is present. Euric ----- Original Message ----- From: "John David Galt" <[EMAIL PROTECTED]> To: "U.S. Metric Association" <[EMAIL PROTECTED]> Sent: Tuesday, 2003-11-04 17:51 Subject: [USMA:27443] Re: Pint/lb vs Liter/kg > "Harry Wyeth" <[EMAIL PROTECTED]> writes: > > The "beauty" I spoke of is not only that a liter of water weighs one kg, but > > that (duh) a milliliter of water weighs one gram. It is a way of getting a > > feel of how small a ml is and how little it weighs. > [snip] > > But I find it a pretty nifty thing that SI has capacity and weight units that > > interlock the way the L and kg do (also think of one cubic meter weighing one > > tonne). The old system doesn't do this, as we all know. > > When I first learned the metric system I thought this match-up was a great > thing, too. Then I learned it wasn't really true. > > Pre-1963, the liter was defined as one kg of water (at max density or > 4 degrees C), but that was actually 1000.028 cc. > > In 1963 the French committee in charge of the metric system voted, not to fix > this discrepancy by adjusting either the meter or the kilogram, but to sweep > it under the rug by redefining the liter as 1000 cc (and no longer related to > 1 kg of water). > > In my opinion, this continuing discrepancy means that the metric system is no > more "elegant" or "integrated" than the imperial system. Indeed less so, if > an imperial gallon weighs 10 pounds. > > Now that they are thinking of getting rid of the standard kilogram block of > platinum/iridium, I urge the authorities to correct their original mistake > by reducing the size of the kilogram so that 1000 cc = 1 kg of water, thus > defining the kilogram in terms of the meter and integrating the whole > system of measurements better. > > John David Galt > >
