The national Republican., 1866-12-11


The Rodman gun has not been subjected
to the test Of battle, in whicha number must
be fred rapidly and continuously. But in
this particular the Rodman and the Arm
strong guns have seen about equal service,
and, according to the experience Of the past,
must each be expected to fail when sub
jected to the real test.
But these guns are made in such q man-
ner that the outside metal Is contracted upon
the inside tube or metal which II incloses,
involving the principle technically termed
initial tension" the degree Of tension ne
cessary to enable them TO withstand the
greatest possible pressure from within. But
It is we'll known that when guns are fred
some heat 10 communicated to the interior
in advance Of its being conducted to the
outside metal to expand 1t uniformly. And
to this unequal heating Of the gun is proba-
bly, due the fact that guns burst when fred
rapidly. And II 80, we must conclude that
the bun that is SO constructed as best TO re.
sist the pressure Of the powder is in the worst
state to resist the unequal expansion from
the heat thus communicated. The strength
Of the wrought iron coils Of the Armstrong
gun is much in its favor, enabling II to en-.
dure extremely heavy charges when fred
with deliberation, il having 10000 lbs. ten
sile strength while the Rodman gun Of cast
iron has tensile strength Of 1000 lbs. q
The cost Of the Armstrong gun in this
country would be much greater than the
Rodman-probably four times as great 1t
has been well said .s.I
"The question Of expense, however, is the
last one TO be considered In an inquiry CT
this nature. On the day Of battle, at the
critical moment in preparation for which
guns are made, an effective gun which sinks
the enemy's ship is cheap, Whatever its cost;
while an fmpotent gun, which imperils the
national honor or safety, is dear at any
price"
1t il maintained, however, by English Off
GERS, that the total cost Of gun, carriage, and
100 rounds of ammunition, Is very nearly the
same for the 9.inch, l2-ton, wrough-iron
riaed English gun, and the l5-inch, 22-ton,
cast-iron, smooth-bore American gun. Al
we have seen above, the English gun is much
the more effective Of the two.
Although the whole influence Of our Gov
ernment before and during the war, and even
to tie present moment has been given fol
smooth-bore castiron ordnance, firing cast
iron projectiles; yet there is at least one higf
official who has perceived that the American
ordnance is wholly unworthy Of natior
which claims to be especially ingenious
practical, and alive to the progress Of th'
mech anical arts 80.
In order to give distinct idea Of the worl
Of which the Armstrong gun is capable, il
will be necessary to quote Capt. NoBLE's de
scription Of the Hercules target, the stronges
target ever fred at at Shoeburyness. Tn
upper half of this target was faced with
wrought-iron plate Q inches thick, and tn
lower half with similar plate inches thick
Behind both plates was compact backing
consisting Of l2-inch timber laid horizontally
and divided by four horizontal iron plate
placed edgewise. This backing rested agains
q skin Of two 3-inch plates. The whole Q
this structure was secured to iron ribs
inches deep. with vertical timber worked il
between them. Behind the ribs were l
inches of solid timber, confined by Zinc
. iron ribs, inside all, and an iron skin. E,
elusive of the 7-inch inside ribs, this targe
was feet thick. The Armstrong gun, frin
$50 pound shot of steel or chilled iron, wit
100 pounds Of powder, has repeatedly PEN
trated this target at distance Of 200 yard
and so effectually that portions Of some
the shot passed completely through the ia
get into the space behind it. In contra
with this fact, the significant fact is mentions
!. that the American 15-inch gun was unabl
n in the fight in Mobile Bay, to pierce Il
sides Of the Tennessee, protected by only
inches of iron and 80 inches Of wood, I
!. though the range was only 10 feet. This I
n suit is just what we should expect from Il
q comparative charges Of powder employe
1t is easy to understand that 100 pounds
powder should do more than so pount
y Meanwhile where is the Parrot gun, o
only heavy riaed gun, with its bursting char
% Of 10 pounds Of powderH
e. English officers prove conclusively, fro
D. their tables of experimental frings, and fro
n the calculations based thereon, that t
" American l5-inch gun, firing 4sO ID. steel sh
" land we have no such efficient projectile,) wi
N so lb. charges, the heaviest the gun will be'
ID is incapable Of piercing the Lord Ward
sr target-a target which represents wood
J vessel, protected by one iron plate
inches thick, l6 IL inches Of timber, and
~ inner iron skin "a inches thick. This
te get is readily pierced at range not exec
is ing 1000 yards by an English wrought-ir'
IT. muzzle-loading, 9-inch riaed gun, weigh
only IL tons, and firing steel shot Of
u lbs, with charge Of A lbs. Of powder.
n. This subject is one Of national iinportan
he and it is to be hoped it will receive the
OF tention 1t deserves.
- Sudden Death OF . journalist.
" On Sunday afternoon, Mr. CHARLES
-, BossoN, q well-known journplist Of Bost
went into the eating-saloon, No. Park X