Re: How long is a Chain?

[pmilne@the.net.nz (Peter)]

In article <Rmj54.2184$Dh3.54369@ozemail.com.au>, chrisjl@iname.com 
pontificates...
>
>
[snip]
>>
>
>The absolute correct figure for conversions in Australia is that 1 foot =
>0.3048 metres -
>this is the accurate and legal conversion figure.  I'm sure that over very
>long
>distances it may be a little out, but, and I stress but, in actual fact I
>think that it
>was the old imperial measurement that was altered to fit in with the newer
>metric system.
>

I remember many years ago looking at a chart in a school metalwork room 
indicating 1 inch = 25.4001mm (I cannot remember the precise number of 
zeroes). The 1949 Pears Cyclopedia gives 25.400mm and the 1964 Concise Oxford 
Dictionary 25.3999mm .  As I understand it, the international community 
agreed on 25.4mm exactly some time in the 1960's, but the practical 
consequences would have been zilch. 1 inch =25.4mm translates precisely to 1 
foot=0.3048m (ie 25.4/1000 times 12).

Peter