, 1877-07-29
PR0JECTILES AND PLATES.

Bible; then compare with it their practice.
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pR0JECT1T,ES AND PLATES
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ihs rover OF q Gun--Armor-PtcrclnE Shell
Recent Experiments in CaunonadinE
Tho Question of Material.
London 73,ne..
Although the power Of gun designed to a
tack armor is generally measured BY the enere
which the weapon sends forth its proiectile, Il
efficiency depends ycry materially On what ma
b. termed tue efficiency Of the proiectile itsel
The material Of which the latter
form, and tough that it may not tiy to pieces a
the moment Of impact II shot "seis M
through excess Of ductility, or becomes shiyere
at the nrst shock, uwing to its want of colle
sion, the power OF penetration is scriousl
diminished. Iu such q cuse proportion Of TIL
s'work - which should he done on the ar1uor l
done on the shot, and the latter is in that de
gree damaged instead Of the arnor TIL,
Palllser pEojecti1e, composed OF iron cast In
I particular manner has proved of immense yaluf
for armor-pcr:inS purposes. being at once
cheap and efficient At one time when the entire
shot or shell was cast chilI-that Is to saw in an
| IRON mold, which rapidly cooled the molten
rAass-there was degree of tension set up
among the particles which, although favorable
to hardness, was extremely liable, il certain cir
cumstances, to produce fracture Thus some
OF these projectiles were actually found to split
while remaining in store Others. again, broke
up in the gun under the shock Of discharge, and
thereby damaged the bore Of the piece, the
projoctile flying forth in fragments, instead
OF maintaining its proper form. Ultimately
1t Tas decided to cast the head only in
chill, tho body Of the shot being cast in
sand. This method gave the body sufficient
toushness to hold together in the gun while
the head had sufficient hardncss for piercing
given thickness OF ar11or. Thus prepared, tie
P2ttiser rmor-piercfng she'll has proved very
effective when fired from heavy guns. But, IN
results have lately shown themselves,
and are exciting considerable attention
among artillerjsts, as we'll as among those
who are more especially interested in
dcyisfng means for resisting the enormous pro
iccties now coming into use To the sisniti-
cance Of these results, so lar as tliey can be at
present apprehendcd, we propose to direct the
attention Of The reader, We do not mean tosaY
that the results are absolutely novel, facts Of
the same kind having been noted as lar back as
1870 and placed on record by Col. Inglis. of the
ROYAL Enc1neers: but the later experiments are
more esDe;,ially remarkab1e. and have an asnect
Of peculiar i,nportancc.
The class Of facts to which we are about to
advert are those which arise when Palliser pro-
space. between them. In the list olace, an 500
pound Pailiser proicctiie was fred from a 13I<
inch uncbambered y9-tou gun, the charce being
100 pounds Of Is inch cublcal powder. and the
gun being directed against a 10-inci unbacked
about sir feet, was finch platc, resting against
an old target. The first plate suffered clean
penetration, but the projectiies entirely failed
TO penetrate the second plate. Il the shot had
simply flown into fragments, the incident would
hare been less remarkable, as this effect would
have indicated that thc first plate had shi7ered
the projcctile to pieces. But, although the shot
was to great extent shattered. there appeared