> > Okay, then how do you convert coulombs, amperes, and volts to non-metric units?
>
> Those aren't metric. At least my dictionary lists those as supplemental units. Good question, though. As new concepts become available to be measured, new units will need to be created. And, as long as we're starting from scratch, then by all means, we'd do well to use a decimal system.

The ampere isn't a supplementary unit; it is one of the seven base units of the SI system (id est, the metric system). It's true that the coulomb and the volt are derived units (the coulomb is an ampere second, and the volt is a (meter^2 kilogram )/(ampere second^3), but I was just listing them as common examples. I *believe* that any measurement which reduces to any other combination of the other six base units -- the meter, the kilogram, the second, the kelvin, the mole, and the candela -- can be converted to non-metric units.

I'll concede that any measurement in SI units could be measured in non-metric units, but only if a new unit for electrical current were defined. That's fairly obvious. I don't know for sure that there isn't a non-metric equivalent of an ampere, but there weren't any conversions in my CRC, which is fairly comprehensive when it comes to that sort of thing.