The Seattle post-intelligencer. [volume] (Seattle, Wash. Terr. [Wash.]) 1888-1914, 1898-05-19
ACcsaACr IN xAaKsxAssHnr.
wsaaerful Work I'm the Recent De0-
haram<nt OF MafaMaas-

Ever since the bemharsreat of Manila
ths world has had its attentson turned 10
TIE fact that sh@ accuracy Of r1arkszna1-
snip OF the guns IN the navy OK tie United
States Is something wonderful.
TIE officials OF the navy have for long
time believed that the accuracy az the
American guns we're one Of their best
points os superiority. hut II was nos III
the sats engagement that il was proved
beyond doubt that their method Of ind
ing the correct range Il excellent.
The accuracy OF the modern American
rifed guns Is one OF The wonders Of mod
ern engineering In an experiment tried
several years ago two shots fred from
sas same gun fell within tairty yards Of
ore another after trayersing distance
OF twelve miles. rs Is deducted from this
experiment that IL modern rife u lad
upon A target with due allowance for the
effect Of the wind. the shot viii ind the
mark.
Unless the distance Of the target IS
known the range and therefore the eor-
rect elevation OF the gun cannot be de-
tsrmlned- The exact discrimination Of the
distance of moving object IS a problem
that has worried the gunner ever since
the day when round shot was first thrown
from the sides OF wooden ship.
7 This determination was CT great import
ance in those days. but now that ex-
pensive charges. costing. for the fargs
guns in the vicinity of 81. so. are used. the
problem becomes Of much more import
ance. Then, too. the Importance Of a
lucky shot cannot be ovsrestimatsd IN
these days.
In former years the determination OF
accurate range was a matter OF mere
suesswork. The gunner would assume a
distance. elevate his gun TO the proper
angie and then fire. IL the shot fell short
OF the mark. he would elevate his gun
more for the next charge. and vice versa.
This answered the purpose fairy well
In those days. but now that sixty-ton guns
are hsed with heavy charges, the neces-
s.fy OF accurate fire is imperative.
The device used In our navy and by
many other navies OF the world il the In
vention Of Lieut.. Fisk, of the United States
navy. now with Dewsy's fleet.
The Fisk range finder ia based upon the
well-known principle of land surveying
with the transit. When an unknown dis
lance q wanted, such as the distance
across a river, a base lire Is measured
along the bank. and the angles which this
line makes with a mark on the opposite
bank are measured by the transit. With
this data the distance across the river
can he determined by the principles OF
trigonometry.
Applying this TO the range finder. a base
line il carefully measured between two
points near opposite ends of the ship, and
over each point a range finder is psrma-
nently set. II the telescopes of the two
instruments are placed upon the same OBJ
Ject at the same time and the angle re-
corded, the data necessary to compute the
distance is given.
In the din ard hurry Of a sea ffrh,
however, ii would be difficult for even the
calmfst officer to make the necessary
mathematical calculations. and, moreover.
as the ships keep moving the angles keep
changing. and the distance between the
ships keeps changing. In order to make
the determination OF the distance auto
matte Lieut.. Fisk has placed his transts
III the circuit or n wheatstone bridge aud
caused their change OF position TO record
the distance OF the object on the gradu-
ated scale OF a delicate galvanometer.
All taat was now necessary was for the
observers at the two range finders to keen
the cross hairs OF the telescope ,,non tha
same point OF the ship at the same time.
and the electric current Translated the
angles into distances and recorded them
by the movement OF needle over an arc
graduated into hundreds and thousands
Of yards
one OF these gaivanometers IS placed in
the coming tower and one at each end Of
the prineipal guns of the ship. The one
FatoF or each instrument has a telenhona
ffansmitter opposite his mouth. so thai
ne Is Kept in constant communication
WIKI the other operator. If the operators
were not Kept in constant communication
serious defects would occur In the road.
ing OF the range finder
ms Is the first device OF the kind eyer
invented, and is practically the only one
or any use. II Is ussd I'm the nsvias ~
several of the powers, and II is cons;5.
efed by many officers TO be one of the
most necessary fittings of the modern
cruiser.