Fulton County tribune. (Wauseon, Ohio) 1883-1925, 1918-05-03


from its course, either to the right or
left. These two corrections are
brought together and determine the
amount in degrees and minutes that
the muzzle of the gun must be shift
ed from the target to the right or
left in order that the projectile will
curve toward it's goal. At last we have
our gun controlled so that it will hit
the target.
Tarry just a moment. A gun, the
text books tell us, is the simplest form
Of gas engine. Did you ever know
two gas engines of the same model
that acted alike? Neither will two
guns of the same model.
The Fifty Per Cent Zone.
If you have an automobile you know
that the piston rings wear out, allow
ing gases to escape, and thus reducing
the force with which the piston is
forced down. Also the cylinder be-
comes scored with the same result.
Now, if you fire your gun many times
the same thing happens. The prOjec-
tile is the piston and the retaining
/ band of copper the piston ring that
seals the bore. If the bore is eroded
or if the rotating bands are not per-
feet O certain escape of gases occurs
and the flight of the projectile is con-
sequently affected
Again, there may be a difference in
the weight of powder charges or in the
weight of the prOjectiles, which will
give slight variations in the flight Of
the projectiles. So that the battery
commander must know the dispersion
of each piece. This he finds out from
| observation of his shots, and it
changes as the gun grows older. By
| figuring the deviation of certain
! group of projeetiles from the target,
and which are known as trial shots or
! fire for adjustment, he finds out what
| is known as the mean error of the
gun. This, multiplied by the factor
.S45, well known to students of prob
abilities, gives the mean probable er-
ror. Multiplying by two, the result In
Yards is what is known as the 90 per
cent zone, within which so per cent of
his projectileS will fall. This compu-
tation is done longitudinally and lati-
tudinally, giving a certain oblong strip
If the center of this strip can be
placed on the target by observation of
fire the battery commander has done
all that he can, and may now open
fire for effect. Four times the sc
per cent zone gives the 100 per cent
| foh nfi q
shots will fall.
knowledge of these zones is all i'm
portant. BY this means he can figure
out how near he can come to our own
first line trenches without numbering
our infantry, and, what is almost as
important, when it is necessary to save
ammunition he can easily compute how
many shots will be necessary to make
a certain number of hits on a given
target.
And what about camoufage? The
enemy airplanes are on the alert anC
all gun positions must be disguised
The battery commander must be {
master of camoufiage, able to erec
shelters and under their cover to builC
his emplacements, while by the exer
else of discipline he restrains his mel
from making tracks about the posi-
tions which will give away to the all
seeing eye of the camera in the al
the fact that guns are mounted there
So that is why the student officer
at Fort Monroe blistered theil
hands and strained their backs erect
ing camouflages and digging dugOut
and bombproofs that is why they dow
and crawled under motortrucks ant
: delved into differentials and gea
, cases, emerging dirty and grimy, bu
happy; that is why they tOiled fo
; hours at night, working out length
problems in trigonometry until angle
= danced before their eyes when the
= tried to sleep and endless chains o
| logarithms curved themselves throug
their brain cells.