The Sun.
London, England, 1861-08-02 00:00:00

211 E SCIENCE OF PROJECTILES.

At the meeting of mechanical engineers at Shef-
field, Sir Wm. Armstrong, president, after sketch-
ing the history of steam inventions, said

In thus glancing at the history of mechanical
science during the last 80 years we see how entirely
our successes have been based upon the possession
of that metal which the Author of nature has sup-
plied us in the greatest abundance. Without iron
all our skill and ingenuity would have resulted in
comparative nothingness; and had it not been en-
dowed with that singular property of hardening by
sudden immersion after previous conversion into
steel, we should have been deprived of the means
of cutting and shaping it to those accurate forms
which our mecnanical constructions require. Its
property of welding is almost equally essential to
its utility, and the combination of these remarkable
qualities in one metal, coupled with the fact of
its natural localities being generally identical
with those of coal, affords the most striking in-
stance of adaptation to the purposes of man that
can be found in the mineral kingdom. It is the iron
and not the golden age which is the true age of
civilisation, and England has led the way in the
march of progress, chiefly through her skill and
energy in producing this metal, and applying it to
mechanical purposes. Iron, unlike all other metals,
has three phases of existence—cast iron, wrought
iron, and steel, each equally useful, and yet so diffe-
rent as to be virtually separate metals. In the ma-
nufacture of steel the town of Sheffield enjoys an
unrivalled eminence, and our discussions on this oc-
casion will naturally be directed to those various
questions of peculiar interest which at present tip-
, ply to that most useful product. I have hitherto
spoken only of the mechanical arts as applied to the
purposes of peace, but I have yet to refer to the
darker side of the picture in speaking of their ap-
plication to the purposes of war. We shall all agree
in condemning war and deploring the suffering it
entails; but we must not regard it as destitute of all
admixture of good. The conquests of ancient Rome
scattered the germs of civilisation over the whole of
the then known world, and similar effects have at-
tended many of the conquests of more modern times.
War also affords a field for the exercise of some of
the noblest attributes of our nature—courage, pat-
riotism, self-devotion, and honour have found their
brightest examples among those who have followed
the profession of arms; and the homage which is
universally paid to military distinctiod shows how
contrary to our instincts are the tenets of those
moralists who place war and crime in the same
category. But, whatever opinions may be held on
this subject, it is useless to take Utopian views of
the duties of nations and the principles which
ought to regulate their intercourse. We know that
nations, like individuals, are liable to quarrel, and
when they do so, having no common jurisdiction to
control them, they resort to arms. So long, there-
fore, as any one nation maintains its armaments, it
is an absolute necessity that others should do the
same, unless they choose, by their inability to re-
sist, to tempt a rupture, and are content to succumb
to the event of its occurrence. Our warlike neigti-
bours, the French, always forward in everything
appertaining to war, have of late years devoted
their energies to two most important subjects—the
rifling of ordnance and the application of defensive
armour to ships. Their advances have necessitated
similar steps on our part, and we have certainly no
reason to suppose that we are behind them in the
race. With the first of these subjects I have been
personally much concerned, and I have also had
opportunities of observing the merits and defects of
the various natures of armour plates, with which
experiments have been made by the direction of
her Majesty's Government. I need scarcely say that
up to the present time cast iron has been almost
exclusively employed in the construction of heavy
ordnance ; but guns made of that material have
not been found adequate to resist the more severe
strain incident to the use of elongated rifled projec-
tiles. This inadequacy of strength becomes the
more decided as we increase the magnitude of the
gun, and since a growing demand exists for more
powerful artillery, the use of cast iron for its con-
struction seems to be entirely precluded. It is said,
and I believe with truth, that in America the manu-
facture of cast iron ordnance has been so far im-
proved by applying water to tool the casting from
the interior as to enable serviceable guns of this
material to be produced of much larger bore than
have been made in England. But it appears that
these guns have not been rifled, and are only intended
to be used with hollow projectiles. This success,
therefore, affords no reason for coming to a diffe-
rent conclusion as to the unfitness of cast iron for
the construction of rifled guns designed to project
solid shot, especially when the dimensions are large.
Even when strengthened by wrought iron hoops,
the tendency of cast iron in a gun :is to become
weaker by every succeeding discharge. This is
owing to minute fractures occurring in the bore,
generally in the vicinity of the vent, and gradually
extending until they terminate in the rupture of
the gun. If, therefore, cast iron guns are to be
utilized at all as rifled ordnance, it can only be by
confining their use to hollow projectiles and light
charges ; but if the same indulgence were extended
to wrought iron guns, equal efficiency would be
obtained with half the weight of metal, and on this
ground alone the superiority of the latter is deci-
sive. Wrought iron made either from " bloom" or
"puddles ball" must necessarily consist in the first
instance of a congeries of welds or joinings. The
smaller the mass and the more it is reduced under
the rolls or hammer, the more perfectly will it be
united, but when a large block is forged from an
aggregation of blooms, it is almost impossible to
render it homogeneous throughout. The flaws in
such a forging will generally be drawn out by the
process of hammering in the direction of the length,
wefielrletnheeeretfuorelunuogtimtuadtieuraial lleytraeffineec.t itsß usttriefngththe
mabiluseadesarosnisb:el,isaufbabtjiaoeiekted to an explosive force acting from
the interior, as in a gun, the presence of such flaws
sit) e weuruound,h t
may
peegeuesne
toob
objectionable
gTh:Otanbi
lreo n t h
a n therefore,cast ir
oanp,p lfioerd,
to be even more the construction of guns, I hold
gintrhoeuraset
esii.nuite it
to concealed flaws, and on that account
than
happen
igi ht
es
ect
resistance, yet it must always be
eiruonueertain and treacherous. If iron, after its
conversion cmcoafirtversion to the malleable form, could be fused, all
,;3ehaorsmotrantenouams
eiriosno,';
' welds would be obliterated, and the mass ren-
dered uniform throughout. Such a material would
a species of cast
meritbut h
ethe
metal appellation‘s,hwhich
u owf
e r eTnht nature,
steel. The form assumed by steel in
solidifying from the liquid state always ren-
ders the material in the first instance hard and
brittle, and it is only under the subsequent pro-
cess of hammering that it acquires ductility and
toughness. This alterative process of hammering is
crystallinebut merely
perfectly effectual when the thickness of the steel
is small, but when it is required to be forged into a
'large mass it appears to be a matter of the utmost
difficulty to effect the required change. It is sel-
dom that the enterprise of English manufacturers
is exceeded by that of foreigners, but in the pro-
duction of steel forgings of large dimensions Krupp,