The sun. [volume] (New York [N.Y.]) 1833-1916, 1891-11-27

Hsrveyed. the former OF which was the vic
tor in the first series OF trials through its
great resistance to penetration. while the
latter came next. and distinguished Itself
by freedom from cracking. The fourth place
will no doubt go to the CARNEGIE low car.
bon nickel Harveyed. the fifth to the Beth.
lehem low carbon nickel untreated. and the
sixth to the Bethlehem low carbon all-stecl
| Harvcyed plate.
or the six plates tested. all were more or
less cracked. since the combination OF four
six-inch shots at the corners and an eight
inch shot In the centre was more severe
than is customary in foreign armor trials.
A useful method Of considering tho cracks
In relation to ench other is to imagine
them stretched out into straight lines.
Taking the Strengthened lengths OF each
plate, tho Bethlehem nickel Harveycd
is the victor by about IS per cent. as
compared with the next best. But since
the object OF putting on the armor is
to keep the proiectiles out OF the ves-
sci, the first point to be considered is
that Of penetration: and there the plate Just
spoken Of Is very decidedly the victor. II
for the purpose Of nscertsining relative ex-
cellence the weight OF proiectile metal
which passes more than half way through
each plate is computed. and these weights
then compared. 1t will be found that tho
Bethlehem nickel HARVEY plate Is tho best
by about fifty per cent.
Thus. while at the first days firing the
Bethlehem high carbon nickel plate showed
itself stouter in resistance to penetration
than the very best of tho foreign plates
tried at Annapolis In September, 1890.
similar plate treated bv the HARVEY process
exhibited. at the second trial, qualities
much more distinctly superior. Just as in
the first trial. one side OF the most success
full plate proved harder than the other. on
account OF a lack Of uniformity In the chill
ing process which had been effected by a
spray Jet OF cold water. On that portion
which was properly chilled the projectiles
broke up almost as il they were Of cast iron;
in fact the Bethlehem nickel HARVEY plate
broke up three out OF the four six-inch
HoLrzER steel proiectiles. Since there is
no doubt that the chilling process can be
made uniform. and the same degree OF
hardness impaired to one side OF the plate
as to the other. now that the error in the
hand OF the plate arc practically those that
may be looked upon as normal in the ordi-
nary manufacture Of armor for our ships.
The examination OF the backs Of the
plates fired at in the second days trial
showed very clearly the superiority Of the
high carbon nickel HARVEY. In
q foreign plate Of that size. if it is not actu-
ally perforated. the bulge at the rear caused
by the proiectile is likely to be Eve or six
Inches. But In the American plate just
spoken Of it was only about one-fourth Of
an inch. 10 ordinary observation there
was presented In the two shots fired at the
right.hand or properly tempered side only
! slight discoloration Of the metal without
bullying. And although the cracks ex,.
Tended through. yet the plate held together
when taken from the backing. showing that |
t was still an effective protection after all |
II the hard tests, while the backing itself |
vas uniniured.
Summing up the general results. these
trials at Indian Head show that |
,ur Bureau OF Naval Ordnance has devel-
,ped and is now turning out for our new
var ships the very best armor in the world.
Having first demonstrated beyond doubt
yHaL dll-SCeel drInOr ID DeCCer IMAM com pOun0
amor. it has now further shown that nickel
steel is decidedly superior to steel without
,he alloy. Next it has shown that Amer-
.an-lnade nickel-steel armor resists pene-
ration much better than the best foreign
slate Of the same material that could he
purchased last year. Finally. It has devel-
'ped in the HARVEY process OF surface
hardening a new principle OF armor manu-
acture. which. in due time. as there is good
eason to believe. will prove far superior to
my system heretofore existing. A further
Tatifying result is that OF showing that
10Th the Bethlehem and Pittsburgh firms
an turn out nickel-steel armor suited to
'ur war ships. the construction OF
which will therefore proceed rapidly
methods OF securing uniformity
n hardening under the HARVEY carboniz-
ne process and saving in the cost OF
pplyiDg it have already been put in
peration. and its perfection during the
oming year will doubtless form the next
riumph in American armor manufacture.
When this work shall have been satisfac-
orily completed, the naval ordnance
will probably authorize its reg
lar application to the nickel armor turned
ut for the war vessels.