The morning news. [volume] (Savannah, Ga.) 1887-1900, 1898-06-18
HOW DIG GUNS ARE AIMED.
Artillery Firing an Exact Science.
RanEe-Finders and How They Are
ODerated


A reporter for the Boston Herald gives
this interesting account of talk with
one of the regular army officers at Fort
Hamilton, in Boston harbor:
In the days of the civil war ranges
were so very short that the gunner had
no difficulty in seeing his target and lay
ing his gun directly upon it. Wind and
speed of target cut no figure, because the
projectile had such a short distance to
pass over that neither had enough time
to act to make any appreciable difference.
But now when firing at a target eight
miles away all of these things make
themselves felt. There Is the rihing In
the bore, which gives the projectile the ro-
tation necessary to keep it from tumbling,
and which will in our service carry the
| projectile to the right Then the drec-
ton and force Of the wind the direction
and speed Of target, the temperature and
| barometric pressuAe of the air, which af-
feet the resistance of the air to passage Of
the projecte, the kind of powder and
! weight of projecule. All these things
| have to be taken into account, and they
each vary under all sorts of conditions, so
! that they can only be figured out for
| each particular shot at the time the gun
| is fired. But they are not such difficult
problems to the officer who lives in an
| atmosphere of such things.
| Most of this information must be work
| ed out from data obtained from firing
! tests, and must Toe thoroughly assimilated
| by the expert artillerist. Then by taking
observations at the time Of firing data are
! obtained from which results can be COM
! puted.
The most important part of the opera
ton is of course to locate the target. The
invention which has enabled us to do this
IS something wholly American deve-
opment of our regular army, which In GER
tain localities IL is so much the fashion
these days to run down.
This invention Is the range-fndcr. 1t
looks simple affair A tail modern tower
| with a substantial foundation, built on a
commanding hight and connected with
the guns-perhaps half mile distant-oy
telephone. At the top is a large tele-
scope adjusted on a polished steel circular
| table. A dial ON the telescope frame Is
| cogged with the edge of the circular table
and gives at any instant the direct read
ing in azimuth. Another dial is so ar
ranged that elevation or depression of the
telescope gives its indicator a correspond
jng movement. This is like the ordinary
transit fitted to read vertical angles. But
In this case, instead of reading angles OF
depression, distances are indicated IN yards
to the point where the line of sight pierces
! the water. An adjustment corrects for
hight of tide
at IS only necessary then, to point our
telescope at the waterline of the ship and
read directly azimuth and distance. These
are rapidly transmitted by telephone %
the guns and plotted on a piece Of draw
ing paper. Three OF these observations,
twenty seconds apart, are plotted, and the
gun has 10 be fired eighty seconds after
| the last observation is taken, or at the
| end of two minutes total time. We have
the location of the target at three differ
ent times. II IS now necessary to compute
L. 4. a.. 4 -NN atart4 100
seconds.
"A vessel running twelve knots an hour
will pass over 200 feet in one minute or
! 800 feet in eighty seconds, so that II we
fired at the point where she was at the last
observation we might miss her 1909 feet
or some fraction of that, depending on her
direction of sailing with reference to US.
If we fired point blank. e., aiming right
at her-we would miss as much as she
would pass over In the time of flight of the
projectIie. This, for a l0W0-yard range,
might be twenty seconds.
I'VE have now the position of the target
at a given future instant, but II Is referred
to the position of the range tower. We
must now correct our data to refer to the
guns position. Then we are ready TO make
corrections for drift due to rlfiing effect OF
wind condition of atmosphere and abnor-
NAL powder and projectie. The gun Is
laid with the resulting data by means of
degrees and minutes marked on the trav-
erse circle of the gun platform and eleva-
ton are on the side of the car
riage, and we are ready TO fire. IL is nee
essary to allow time-called time Of
hight'-for the projectile TO reach the tar
get at the end Of the eighty seconds, so
the guns must be fired that long ahead of
time.
when you consider that all of this work
must be done in eighty seconds, you see
that one has TO count his time by fractions
ftro anti fan a
longer time can be allowed for computa-
tons, etc, as uncertainties increase 5
about the fifth power of the time. This Is
where the discipline of the soldier comes
in, and II can be acquired only by years
of training
",rhe aiming Of the gun Is all science
now and needs experts. The firing and
loading are the only work which the un-
trained mind can find work at. And even
in these things, you understand, there IS
need of GOODNESS and experience, for theee
big fellows arc delicate machines after all,
and are worked 4y levers, have electrical
appliances and are in other ways too pre-
cious to trust TO unframed hands.
This may not sound TO dreadful here in
the calm of a peaceful spring afternoon.
But imagine looking up sines and cosines,
plotting accurate curves from mathemati-
al data, under a hail OF projeci,les,
with shells and bombs bursting around
you, Fancy placidly sighting your tele-
/, scope in the range tower which a we'll
directed shot may cut away from beneath
you. And your hand must not tremble,
your mind must not be distractedW
The civilian seemd rather impressed. He
could only venture, timidly, that II did
seem as if there were great odds against
the ships.
80 there are. But they have advant-
ages, too. In the Japanese-Chinese war
the JaDs, being clever got ahead Of the
Chinese predictions of their position by
running ahead fun speed and then sud-
denly Stacking up, so that the Chinese
gunners began 10 grasp that ruse; then
they changed their tactics and would ad-
vance slowly at first, then suddenly crowd
, on all steam and speed away, leaving the
gunners far behind"
"Oh! then you can get around The alb
soluteiy scientific accuracy "
The artillery officer laughed. Yes, hut
you must remember the Japs were dealing
/ with the Chinese. We know how to over-
come that. Tow? OH but that's telling
The CIVILIAN wanted 60 know who was
responsible for the range tower, and was
told that 1t wa's the Invention OF Lieut.