Daily press. [volume] (Newport News, Va.) 1896-current, 1898-04-12
NOW BIG GUNS ARE AIMED.
Possible Now to lombard IN Enemy
a Long Way on.
tNew York Evening sun.


Th,. riiiing OF guns and consequent
greater accuracy and luMS"r range
given to modern pEojectil@S mas llit"e
!, possible. To lombard an enemy from
{, much greater distance IMAM tou'u
formerly be done. AS 4 result OIL
this il has become necessary 10 nave
some instrument With which to deter
mine accurately the distance OF the
| object of attack i'll order THAN the gun
may receive the elevation called for-
| Itunge-iindcrS, as such Instruments
are called, are, for the most part,
founded on lrigonotnrtry, though some
are. based on the velocity OF sound rs
transmitted by the air. These nov
| ever, are no longer used, Tor ltcbSa'
| reasons. The nrst ranSe-iilldefS IN
| vented We're small and Simple, ana
could easily be moved from place To
! place. The Knowledge OF q base lilt
| was necessary TO their use eitner ifoti'
| the. butt OF The instrument Whc1i II vas
| directed to the extreme ends Oh SoI'lS
| object the size OF which Was known,
| or. from some point OF OBSERVATION
| where I, base line could be measured
| AS the range and accuracy OF guns
! further increased these instruments
| were found To be too Imperfect Tor inc
| requirements
| The chief impcrfcction of earlier
| range-tintiers was that as the instru-
ments We're adjusted simply by the eye
| they could not he directed with enough
accuracy They We're usually held in
| the hand of the operator and therefore
| We're not sufficiently firm. Modern
range-iinders are equipped with an
| adjusting telescope and are placed OF.
| a stationary stand. from which mea-
I Sureinents are. taken. The ideal range
| finder to fulfil all demands made upon
| it, would have TO have absolute ac-
curacy in regard to all ranges and be
entirely independent of the physical
| advantages or disadvantages of the
| place. where ii is TO be used.
| Such an instrument is. however. at
1 present unknown, and triangulation is
the only means used to find the range
Of a target. The range-iinders now in
use at the fortiicatlunS that defend
| the entrances of the important har-
! bors of our scahoard are based on
| trigonomctric principles and are of two
| kinds The more simple and easily
| operated of these is placed in a tower
| or on an elevation near the battery
| whose fire it is to direct.
The adjusting telescope is then di-
rected at some object whose distance is
| known: from this point the telescope
| is then turned toward the object
| whose range is to be determined and
the angle between the two is recorded.
| l.y means of this angle and the base
! line or known distance from the in
| strumcnt TO the object at which it is
at first directed. the distance to the
| second object is determined. me flrSl
| object is usually anchored in waters
| adjacent to the battery IN order TO
| avoid any error that would arise from
the rise and fall of the tide il it We're
situated on shore. Only one operator
is necessary to use this range-ii finder.
The principle of the other range
| finder is much THE Same. but two opero-
tors are necessary ana photographic COM
| nunirsrt+pn between them and the hat
,trN is Indispensable. The operators
are paced ait a certain known distance
from each other with their Instruments
| anll adjusting Telescopes. Zach Keeps
his ;,4!e.N,upe pointed at an approaching
vessel. vr'h.. srse'es miade by an lllfl-
ginary line between the Two observers
and imaginary lines extending from
them 10 the vessel is THUS constantly re-
corded \ side and the two adjacent
angles of a triangle whose verteX is
ths vessel being thus known, it is only
necessary to solve the triangle TO deter
| mine accurately the vessels Instance
The angles are tclesraphed sinful
| tanpouSly from the operators to the
| officers who direct the fire Of the guns,
and then in turn. determine the range
and instruct the gunners how TO ain!
thei, guns The officer in command
of a battery is somewhat Handicapped
in directing the accurate aiming Of
J mis- guns by the natural error of the
| guns and by varying atmospheric and
weather conditions. The powder charge
Of n gun, though of correct weight ard
density. may not he OF normal strength
and the muZzlc velocity of the projcc-
tile may be affected.
Variations in the density of the at
nosphere alter the resistance to the
passage OF the projec:ile, and thus at-
feet its range. Wind also affects both
the range and direction of the projcc-
tile The range table of a gun Is
therefore prepared from the result OF
. experimental practice and corrected t.
mean height of barometer ana Their
momctcr and 4 mean density of atmoS'
phcrc. Allowance is also made for any
J wind variation. AS the larger gun.
ut our Notifications can only be
loaded and fred at intervals of three
minutes. and as the object OF their fir
: would. as n rule, be constantly chang
= ing its position, there would be littl
to be gained by experimental firing.
:. -, however a shot that has been cor
pliss' NY aimed by means sof the range