Stone weight measurement.

[STAH]

Please can someone explain to me what the origin is of this weight measurement, and what stone (if any) was used to determine the weight.

Many thanks.

[Grunty]

These sites give an explanation.

http://www.scan.org.uk/measures/weight.asp

http://www.npl.co.uk/mass/faqs/history.html

[STAH]

Thanks.