The Sun.
London, England, 1860-03-08 00:00:00

pound projectile need to be ? How rapidly must it
spin on its axis in order to keep point foremost
during its flight ? How soon would a quill-like
tube foul from the combustive results of exploded
gunpowder ? And lastly (granting, for the sake of
argument, any conceivable range), what harm would
any number of quill-like bolts do the walls of a for-
tress by penetrating or even transfixing them?
These are a few of the considerations which must
necessarily influence any practical_ artillerist. Had
Sir W. Armstrong gone in for mere range, he would
have worked with guns of less calibre, for any par-
ticular weight, than he has done. He rightly ap-
preciated the fact that artillery power in these days
means shell-power; and, to be thoroughly efficient
for shell-power, a gun is required the calibre of
which is not less than a certain measurement,

incapable of being stated exactly, but appreciable
within small limits nevertheless. So fully is this
fact understood, that Shrapnell shells are never
projected by Continental artillerists from smaller
smooth-bore tubes than twelve-pounders ; —so
thoroughly recognised, that, prior to the adoption
of rifled field-pieces in the French service, the
Napoleon gun, as it was called, was proposed to be
used in French field batteries exclusively. Nov,
what was the Napoleon gun ? Why, a gun short
almost as a howitzer, so that large bore might be
combined with light weight. Range was thus offered
up as a sacriiice to competent shell capacity.
At this point we cannot do better than present
authentic measurements of the Armstrong guns,
preparatory t 3 a comparison of them with the par-
ticulars of Mr. Whitworth's ordnance.
MEASUREMENTS OF ARMSTRONG ORDNANCE :

Diameter of bore :-100 pounder, 7 inches ; 25 pounder,
3.75 inches; 12 pounder, 3 inches ; 6 pounder, 2.5 inches.

MEASVREMENTS AND WEIGHT OF WHITWORTH'S
ORDNANCE AND PROJECTILES :-

The 3 pounder, minor axis, 1•48 inches; major do., 1.6 do.;
length, 6 feet ; weight, 1 cwt. 3 qrs. ; pitch of rifling, one
turn in 44 inches ; weight of shot, 2.751 b. ; length of shot,
615 inches ; charge of gun, 7 ounces. The 12 pounder,
minor axis, 2.8 inches ; major do., 3.1 inches ; length, 7.5
feet ; weight, 8 cwt.; pitch of rifling, one turn in 5 feet ;
weight of shot, 121 b. ; length of shot, 9.5 inches ' • charge
of gun, 1.761 b. The 80 pounder, minor axis, 5 inches;
major do., 5.3 do. ; length, 10.5 feet ; weight, 4 tons ; pitch
of rifling, one turn in 8.5 feet; length of shot, 16 inches ;
charge of gun, 121 b.

Before arguing on the premises furnished by these
data, it will be necessary to draw attention to the
form of Mr. Whitworth's rifling and projectile.
That gentleman commenced by manufacturing rifled
arms, large and small, with hexagonal bores. In-
deed the hexagonal bore came to be associated at
length with the name of Whitworth, as though he
were the first manufacturer who had adopted it.
Nevertheless he has of late abandoned the hexagonal
bore. His recently constructed small arms and
ordnance have really a 12-sided rifling—the ordi-
nary diamond-grooved system of gunmakers in
point of fact. Mr. Whitworth's small-arm projec-
tiles actually fit the barrel throughout their whole
length ; but how little this remark applies to that
gentleman's ordnance bolts will be seen from an
inspection of the annexed woodcut—
WIIITWORTH'S CANNON SHOT.