NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: The mil as a unit of angle.
From: Brooke Clarke
Date: 2003 Mar 11, 17:40 -0800
From: Brooke Clarke
Date: 2003 Mar 11, 17:40 -0800
Oops, That should have been 1 yard in 1,000 yards is approximately a mil. Brooke Clarke, N6GCE George Huxtable wrote: > Dour Royer said- > > The use of a mil-compass is also needed.Mil does not > >> stand for military but mil:1,000th of something.The mil-compass is hand > >> held and has 6,400 seperate & equal segments in 360*.The compasses are > >> also known as lensatic compasses.You can get great accurecy in > >> distance,height and position useing the mil. > > Response from George- > > It's good that we keep on learning new things on this list. I had never > heard of the mil as a unit of angle, nor had I come across insertion and > resection in Doug's context. > > However, it's rather mind-boggling to discover yet another unit of angle, > 64,000 in one rotation! Presumably, this is to put compass "points" at > round-numbers of units. However, this convention shares many of the > awkwardnesses of our 360 degree system. It makes the heart sink, when > there's an obvious logical measure of angle just waiting to be adopted, the > Turn, to be subdivided into 1,000 milliTurns. When you go through one Turn > you get exactly back to where you started, so calculations involving angles > exceeding 1 Turn just require dropping the integer part. It's decimal all > the way, none of these nasty sexagesimals. Of course, it shares with all > other decimal units the disadvantage of not dividing easily into 8ths and > 16ths and so on, as were used for compass "points". But we don't use > compass points much these days, courses and bearings are nowadays > understood simply as a number. > > Of course, there are serious snags about making such a change. It would > require recalibration of all our charts, compasses, and sextants. Not for > the faint-hearted! > > George Huxtable. > > ================================================================ > contact George Huxtable by email at george@huxtable.u-net.com, by phone at > 01865 820222 (from outside UK, +44 1865 820222), or by mail at 1 Sandy > Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. > ================================================================