21 Apr
2016
21 Apr
'16
5:25 p.m.
On 2016-04-20 06:59 PM, James Knott wrote:
One chain is 66 feet,
Or 20 metres.
… if you're not fussy about 117 mm difference. Surveyors tend to be. The only unit of measurement I know of that was deliberately designed to be friendly for both metric and not-metric* is the HP-GL unit. It's 1/40 mm, or exactly 1/1016 inch. Stewart *: there are so many variants that there isn't one brief useful term for it.