Evening public ledger. [volume] (Philadelphia [Pa.]) 1914-1942, 1914-09-18
TARGETS SELDOM VISIBLE
IN HEAVY GUN FIRING
Artillerists Guided by Scientific In
struments, Which Calculate
Defleotion.

How cannon are used in an actual bat
tie is a most interesting subject concern
| ing which little information has been
available, and a description published in
the special war number of the Scientific
American is particularly timely in en-
ablng the descriptions of engagements
| between the various European forces to
| be better understood, as will he apprc-
ciated from the following extracts:
In actual battle the guns OF a battery
| are lined up and one loaded caissun is
| placed next TO each gun. The entire bat
| terry is behind cover, and generally can
| not sec the targets. The fire Is directed
! by each gunner aiming on a designated
aiming point, with an instrument set at
| a given DETECTION, 80 that the gun will
! actually point at the target. This de-
Election Is calculated by a trangua-
tion method by the battery commander
who is located some distance away from
the battery either on elevated ground.
on a ladder, or In a tree. The German
system OF obtaining the detection Is to
measure the angles carefully, by means
of instruments, thereby attempting to
make the first shots effective; while the
tendency of the French system is to es-
timate the first DETECTION. fire quickly,
and by observing the shot make ncces-
Tho ranges are obtained by sclt-con-
taned base range-finders which are ac-
curate within 900 yards for 5000 or 5000
yard ranges.
Within the last few years the subject
of equipping the field artillery with larger
calibre siege guns and howitzcrs has been
given extended studies.
The object of howitzcrs is mainly to
fire heavier proJectile with n lower
velocity at a much higher elevation and
longer range. Assume, for instance, the
enemy's infantry entrenchcd behind cln-
bankments. With a high velocity tho
trajectory of the projectle for given
range Is very fiat, SO that the troops would
be able to sit behind the cover and have
all projoctilcs either strike the embank-
ment or pass over their heads. For this
emergency a battery of howitzers is
called into action. BY reducing the charge
the projcctile may be started at n higher
elevation. which causes the projectilc to
fall to the ground in II much more nearly
vertical path, and enables it to be dropped
back of the embankment. AS a concrete
example, assume the enemys infantry
behind earthen cover at 5000 yards The
slope of fall of the French projectie at
that range would be about : degrees or
l on S. this gives n considerable space
behind wall that would be practically
Immune from the artillery fire.
BY calling t.I-inch howtzer battery
for this work, the artillery commander
may fire JG-pound projectilc with 900
feet per second muazlc velocity which
would sire him at 5000 yards a slope of
rail- Ion i.3, or he may remove some
powder from the charge and fire the pro-
jectile at go feet per second muzZle
velocity, which would give him a slope
OF fall at 900 yards of / on is, with which
1t would be practically impossible for the
enemy to remain behind the cover.
Another object Of these heavy cannon ia,
that battery can be put in position TO
sweep large field and with its long
ranges prevent the cnemy's lighter artil-
lery from coming within effective reach.
The velocity of these howitzers is prac-
tically the same for all countries, and is
about 900 feet per second for the longest
zones, while the calbcrs arc approXi-
mately 3S-lnch with Il 30-pound projectile,
t'T-inch with 60-pound projectile. and g.
inch with l20-pound projectle.