330 
ARMOURED DEFENCES. 
With the earlier collapse of simple steel armour before us, our 
English manufacturers were set to work, in 1877, to see if they could 
not produce something which, while it should have the resisting 
qualities of steel, should be free from the serious defect of breaking up 
under almost a single heavy blow. 
In the course of that year and the following, therefore, we tried 
every possible kind of armour that could be produced in Sheffield for 
this purpose. 
I think more than 50 methods were subjected to trial. Some were 
utter failures, some promised well at one time and failed at another, 
but the result of the whole has been that compound plates, in which 
a steel face (about one-third the thickness of the entire plate) has 
been perfectly welded to a wrought-iron back, without injuring the 
two materials, have met with most success. 
The object of this kind of armour is, that while the face shall be 
sufficiently hard to break up, or to take a great deal of work out of, the 
shot, the soft wrought-iron back shall hold the mass together, in spite 
of the cracking of the steel face. 
One of the principal points, of course, has been to determine the 
best degree of hardness, or, in other words, the best proportion of 
carbon that should be given to the steel for these purposes. 
As this matter is still under consideration, I cannot say more about 
it on the present occasion than that the manufacture of these com¬ 
pound plates can scarcely yet be said to be uniformly successful, but 
that when they are good they seem to offer, for a few moderately severe 
rounds at least, resistance compared with that of plain wrought-iron 
plates as 4 to 3 ; that is to say, a 9-in. compound plate will be about 
equal to a 12-in. iron plate, and, with oblique fire, they certainly are 
very successful in turning and breaking up shot of all kinds of form 
and material. 
The trials have been made principally with 7-in. and 9-in. guns, 
with both direct and oblique fire, and with all kinds and forms of pro¬ 
jectiles, and these are shortly to be continued for the Admiralty, at 
Shoeburyness, with much greater thicknesses of armour, for which the 
38-ton gun is to be used. 
Within the last few days the French have carried on important 
trials at Gfavre, when some steel plates, averaging 18 ins. in thickness, 
produced by foreign makers, and a foreign-made wrought-iron plate 
with a hard face, and a compound plate made by Messrs. Cammell, of 
Sheffield, were fired at by a 32 cm steel B.L. gun with 760-lb. projectiles 
and 210 lbs. charge of powder, and so far as my information goes, the 
English compound plate behaved the best of all. The steel plates 
broke up very freely, as usual. 
Until further experience has been gained with heavy blows from 
large projectiles of hard material, it would not be wise to speak con¬ 
fidently as to the ultimate success of this kind of armour. 
In the meantime the Admiralty have adopted 9-in. compound plates 
for the turrets of H.M.S. “ Inflexible.^ The French I hear are 
seriously taking it up for their ships, but we have not yet decided to 
use any of this kind of armour in land works. 
