Grand Forks herald. [volume] (Grand Forks, N.D.) 1916-1955, 1918-11-20
OPERATION Of
MACHINE GUNS
NOT DIFFICULT T / j. I
Great Change Has Been
Made Since They Have
Been Used.

Camp Kearny, San Diego, Cal,. Nov.
/, 20.-The whole science OF trigonom-
etry. as applied to the firing of artil-
lery and machine guns measurement
, of military distances and other mill
tary matters has been reduced to a
single simple rule, almost a "rule Of
thumb" The man with an average
mind, embering this rule. need not
worry about complicated mathemati-
cal formulas for figuring this and that
factor in ''4iring data"
This great change has been
wrought in American military affairs
by the general application of the
j, mil system" A "mil'' is "that angle
whose tangent is 1,oo0.'' Upon this
fact has been built a scheme Of an
gular measurement used for distance
machine gun and artillery fire, locat-
ing targets or other points by their
angular distance familiar reference
points, figuring clearances Of barrages
over the heads of troops clearances
of streams of bullets from machine
guns over a masking hill, in fact,
nearly everything connected with fire
control.
The infantry and the machine gun
ners use the actual mil in their work,
but as the artillery deals with quad
A<~AAS1b
sary for their measurements to be
capable of division into quarters.
Hence they use an arbitrary mil a
trffie smaller than the actual one.
Officers of both branches frequently
have their field glasses marked with
fine lines a certain number Of mills
distant from open object another one
is. As the marking is done only in
the series of lenses through which the
1n$ se, ark <@~ NA~y(~
when the glasses are in ordinary use.
Looking at target through such a
pair of glasses, for instance, an Of
1icer can see exactly how high or low
his battery is placing, its shell bursts
and can order the appropriate correc-
tion. Being, told that an enemy col
umn is at a point on hillside 20 mills
above and 100 mills to the right of
iome familiar aiming point, it is easy
'or an officer to locate it.
a great many soldiers, particularly
machine gunners, carry mil scales
WHICH they use for measuring, and In
IN emergency, a scale can be made
from a string, or a. notched stick that
Will do good service The mil scales
in their simplest form are.only gradu-
<, ate9s cellulofd scales withsa string tc
mark the distance from stthe eye al
which they should be held. The bet
toI OHeS, uOWeVer, carry q COmpn-
\, Gated arrangement Of circular rules by
which factors of clearance. or dis
tance over troops or hills. streams OF
bullets must go for safety or for ef-
fective fire on enemy targets
With a mil scale, even of the
simplest, it is possible to find the
range to enemy targets by taking OBJ
servations of their angular distance
from some prominent point the dis
tance between the two points whence
observations are made being knowr
or found by pacing. obviously
knowing the length Of the base of any
triangle, the distance between obser.
walton points. and the angles formed
by its sidee-easily determined by the
mil scare readings-it is simple
mathematic proceeding to ascertain
the distance from the base to the
apex, the target.
For hasty observations not for di.
recting fire but to locate targets, etc
many officers proceed on the suppo.
sition that the angles formed by sight.
ing over the edges of their outheld
fist is SO mills. The factor varies o1
course, with different officers, but it Il
easily determined for each officer ant
does not vary for him.