The Sun.
London, England, 1854-12-28 00:00:00

TILE STRONGEST MATERIAL FOR GUNS.

Cie following letter has been addressed to a con-
tona;D:;rary
r,—The Government has shown wisdom in giving
Aire Nasmyth their support towards developing his
plats. I have no doubt that under his hands the
cape abilities of wrought iron for gun metal will be
hrernght out to the uttermost, and his skill and ability
.
leave
w
nothing undone to insure the best possible
resu t. I would, however, take the liberty of sug-
gest in.g to Mr. liasinyth that there is a material far
sal-et:nor to wrought iron. I allude to cast steel. A
bar .of good English iron, one inch square, will
frus-
tum a weight of about 25 tons ; a bar of ordinary
cast, steel of the same size will sustain GO tons. The
pc:e'er of cast steel to resist wrenching asunder is to
that; .of wrought iron nearly as 191 to 101, and cast
stettl can be made perfectly uniform and h'omogeneous
throstighout its mass, whilst with wrought iron, uni-
fornt ity of texture, and solidity, especially in large
masi es, can only be approximated to, and many imper.
fectic tns must at all times exist when large masses of
wrost ;ht iron are required, and which can only be
form d by welding together a number of small pieces.
The c bjections to cast steel are these :—lt is difficult to
obta!i: a it in large masses, for it is only pro curable by
melt.a )g steel in clay crucibles, usually containing about
40Ibe:, each, and two of which occupy one melting fur-
nace.. I have so far improved upon this process, that
I obi: tin 561bs. from each crucible, and I work four such
cruci 0 les in each furnace ; that is to say, one melting
furna c e will yield 2 cwts. of cast steel, and therefore to
cast a a ingot ,fitted for being drawn under the steam
baron no. into a gun capable of carrying a ball of 3 cwt.
250 s ueh melting furnaces and 1,000 crucibles would
be regroired, supposing the gun to weigh 25 tons, and
the ct rn tents of all these crucibles would have to be
poureit very quickly into ono large cylindrical"iron
mould. to form the ingot. Whether it be possible
to ;i Ingo matters so as to enable this to be
done I leave it to the great manufacturers of cast
steel ,;a1 Sheffield to decide ; but my own impression
is that- lit is not merely pessille but a simple question
of h eing a sufficient number of well-disciplined
works ni tn and a suitable workshop, for the melting fur-
naces do not occupy much space. In this manner one
ingot oil from 25 to 30 tons weight could be produced
daily at, one such establishment ; and the next question
is, Can such an ingot be drawn under the hammer into
shape r: This Mr. Nasrnyth can decide. Another ob-
jectio a to the use of cast steel is, that when manufac-
tured 1 .ufileisiet/yeesoft to Ineuro toughness and strength
it is p c rous in its structure and full of cavities, which,
thoug:i they close up under the hammer, never unite so
as to p ecome solid ; and when the cast steel is made
sufficies it!y hard to form a solid ingot, free from the por
„us in fie rnal structure, the steel is then brittle, like cast

Now, I offer to show Mr. Nasmyth or the Garet nment
authori ties how to make cast steel, which shall form a
perfect,l y soli3 ingot and yet possess the utmost strength,
and I c tn furnish Mr. Nesmyth with ingots of this steel
to be rt lied and farmed into tubes of given dimensions,
whicii, when bored and tested by hydraulic pressure,
shall su stain double the strain of that which any wrought
iron in bes of similar dimensions can undorp w:t.4.out
yieldiel •. r&s cast steel. including the expenses of
melting; , crucibles, materials, &c., would not cost more
than 3e 1. per ton, and supposing that it is possible to east
so larl re an ingot and to draw it into shape when cast,
and t; le a to bore it, the guns thus formed would be all
but irap erisbable, and not liable to the wear and tear
which t,' le weaker materials of wrought or cast iron are
subjec ''to. Besides the strength and tenacity possessed
by ow t steel in its ordinary state, it may readily be made
still tf other and more tenacious either by simply anneal-
ing it a: u dull red heat for some hours and then allow-
ing it t 3 cool slowly corered with sand or ashes, or more
readily, by bringing the mass of steel to a temperature
of 610 &legrecs, and then suddenly immersing it in cold
water..---I am, sir, your constant reader,

ROBT. MUSFIET.
Wegl, Dean Steel Works, Colctad.

NVAV p IE2 AND RAI T, W AY PLANT FOR
ALAKLA

The following letter has been addressed to a con-
tempos.; .ry
Sir,— -The Wildfire, with her " navvies" and railway
plant, eas, I perceive by a late Daily News, still at
Birke al lead, waiting a wind—and wait she way for a
month, •.; or if she sails, be that time before she gets out
of the- ,Channel. Any one who has paid attention to
events. knows that in ordinary years, if a vessel does
not 1€ we the Mersey before the second week in No-
vember, unless she is a clipper, the great chance is when
she doses leave she may be knocking about for six weeks
before ,she gets clear.
Wimt are these railways for if they are not to be
availed:. of in the present emergency ? To say nothing of
the exigency, at a less cost by far than " finding" and
pa,yinz ss. per day to each " navvie," and the hire of the
vesseL during such detention, the whole plant and men
could. Ise despatched per rail by the " shortest route" to
Marseilles, and thence per steamer to Balaklava.
Sma2l steamers—the class now in requisition for a
winter• voyage—(we are always in extremes)—offer little
better alternatives than sailing vessels, as they cannot
sheer ta heavy weather.— Yours, &c.
ONE WHO KNOWS ruElVlansEr WEEL„
Dec. .26, 1854.