[Magdalen] Rods, knots and chains, oh my!

[Roger Stokes]

On 30/07/2016 22:55, Lynn Ronkainen wrote:
> https://en.m.wikipedia.org/wiki/Rod_(unit)

I'd forgotten about the knot which is a unit of speed still used in 
aviation.  It is 1 nautical mile per hour, a nautical mile being the 
distance represented by 1 minute (1/60 of a degree) of longitude at the 
Equator, acrually defined now as 5,080 ft.  Using knots as a speed 
indication for aircraft means that you are being neutral, using neither 
the imperial nor the metric measure of speed.

Roger