chidsey@smoke.brl.mil (Irving Chidsey) (04/24/91)
From: Irving Chidsey <chidsey@smoke.brl.mil>
emery@aries.mitre.org (David Emery) writes:
<In general, angles in artillery are measured in "mils". A "mil" is
<the angle subtended by 1 meter at 1000 meters. (There are about 17
<mils per degree, and 6400 mils in a circle).
NEVER! A mil is NOT the angle subtended by 1 meter at 1000 meters.
It is, by definition, 1/6400th of a circle; that makes it very close to the
angle subtended by 1 meter at 1000 meters. The army does not yet have
sufficient statutary authority to change the value of pi.
--
I do not have signature authority. I am not authorized to sign anything.
I am not authorized to commit the BRL, the DA, the DOD, or the US Government
to anything, not even by implication. They do not tell me what their policy
is. They may not have one. Irving L. Chidsey <chidsey@brl.mil>vvirrankoski@cc.helsinki.fi (04/29/91)
From: vvirrankoski@cc.helsinki.fi chidsey@smoke.brl.mil (Irving Chidsey) writes: > emery@aries.mitre.org (David Emery) writes: > <In general, angles in artillery are measured in "mils". A "mil" is > <the angle subtended by 1 meter at 1000 meters. (There are about 17 > <mils per degree, and 6400 mils in a circle). > > NEVER! A mil is NOT the angle subtended by 1 meter at 1000 meters. > It is, by definition, 1/6400th of a circle; that makes it very close to the > angle subtended by 1 meter at 1000 meters. The army does not yet have > sufficient statutary authority to change the value of pi. In fact, both of You are right. As definition, mil is the angle subtended by 1 meter at 1000 meters. That would mean that in the circle there would be about 6283 mils (and 1 mil is about 3.6'). But in practical reasons it has been defined that circle is more round number, that differs in different countries and history. The most usual is circle = 6400 mils but in the Finnish Armed Forces and in the cross-country track finding they use circle = 6000 mils and in the Swedish Army circle is 6300 mils. I'm not sure about the last fact, becouse my information is quite old.