ARMOURED DEFENCES. 
327 
In 1877, a target, composed of four 8-in. rolled iron plates, with 
layers of 5-ins. of teak between them, was set up, at Shoeburyness, 
for the trial of the 80-ton gun of the pattern made for H.M.S. 
“ Inflexible,” and for the turret on Dover Pier. Two rounds were 
fired—one before, and one after the gun had been chambered. The 
Palliser projectiles weighed 1700 lbs. The range was 120 yds. In 
the one case the shot was fired with 370 lbs. P 2 powder, and struck 
with a velocity of 1495 f.s., and total energy of 26,400 ft. tons; in 
the other, 425 lbs. P 2 powder gave a striking velocity of 1585 f.s., and 
an energy of nearly 30,000 ft. tons. 
In neither case was the target perforated, though, as the shot had 
got their noses an inch or two into the back plate, it was a good deal 
cracked and bulged behind. Had the plates been 7 ins., instead of 
8 ins., thick, probably the last shot, at any rate, would have got through. 
I abstain from noticing, in much detail, the trial of an armoured 
target at Meppen, last year, for the same reason that I have excluded 
many of our own experiments—namely, because the results were, from 
various causes, of an inconclusive character. 
The target in this trial consisted of two wrought-iron plates, thus — 
Front plate, 12 ins. thick, 16 ft. 4 ins. long, 3 ft. 9 ins. wide. 
Bear u 8 ins. n 18 ft. long, 5 ft. 4 ins. n 
with an interval of 3 ins. between them, lightly filled with wood (fir, I 
believe). 
The gun was Krupp's long 24 cm gun; the projectiles were of steel; 
the charges and velocities were as follows :— 
Powder, Velocity, Striking 
Projectile, Prismatic (1 hole). striking. energy, 
lbs. lbs. f.s. f.t. 
348*3 165-3 1876 8508 
346-5 i, 1852 8244 
The front plate proved to be very brittle, and the rear plate was 
much underwelded. 
In each case the shot went clean through and some 2000 or 3000 yds. 
beyond the target. 
This easy victory by the shot may be accounted for, partly by the 
inferior quality of the plates, and partly by the bad arrangement of 
the target, which was not bolted together, I believe, and which 
certainly had too small an interval between the plates. 
The gun used in this trial is only equal to perforating an 18-in. solid 
wrought-iron plate at its muzzle, and therefore should be only just 
capable of getting its shot through a well-constructed target of two 
plates making up together 20 ins. 
It will be observed that I have hitherto been dealing mainly with 
experiments on wrought-iron armour. I wish now to say a few words 
on other kinds of armour. 
And first, with regard to cast-iron :— 
As early as 1867, we tried, at Shoeburyness, some iron blocks cast in 
chill. In these the extreme hardness of the chilled surface was well 
illustrated, but the brittleness was so marked that we hesitated to 
go further with this kind of protection. 
Chilled ca»t« 
iron armour. 
