>> >> Yes. But inches also have a change in scaling constant when you change >> to feet, and another when you change to yards. (Arguably degrees have >> too when you change to minutes and seconds but in practice fractional >> degrees are used as an essential part of using them in calculations). >But there's no need to change to feet or yards - I can say that a thing is two yards, six feet, or 72 inches long, without losing precision, in the same way as I can say >that something is two metres or 2000mm - it's just that the Imperial measures aren't related by powers of ten. I don't see that it makes them different! Someone earlier mentioned mathematicans being "lazy" for not wanted to factor their angles to degrees- an entirely arbitrary unit that isn't even correct (the 360 days/ 360 degrees in a year thing). 2pi is much neater and more appropriate for maths. But it's this same laziness, IMHO, that makes the majority of people assume base 10 is always best, hence metric. We're drilled into working mentally in base 10, but other bases are often "better" - base 2 and base 16 being obvious examples for this community. But the imperial system has one great advantage over metric- more factors. 12 has the factors 1,2,3,4,6 ; wheras 10 has 1,2,5. These factors are often handy when working with high precision. And frankly, I find it annoying that all my components and libraries stock parts with a 2.54mm pitch. Why not quote .1" ? It's more accurate, cos that's what they actually are. On a separate note, I rather like the imperial system: it requires more intelligence to use, and I'm an intellectual snob. Also, I think a pint is a far better measure than it's closest metric equivalent (because it's bigger- more beer). And yes, I'm talking imperial, not american, where a pint is 20oz ("a pint of water weighs a pound and a quarter"). I was most dissapointed the first time I went to america to discover how small their pints of beer were. -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics