THE ROYAL ARTILLERY INSTITUTION. 
49 
and struck the 7|-in. plate, where it had the teak backing. The indent 
made was 6*2 in. deep, and its diameter about 12 in., or rather a circular 
piece of this diameter was driven in to a depth of 6’2 in., and nearly, if not 
quite, separated from the plate, which was of very good quality. There is 
therefore here a well defined measure of the full force of this shot. Besides 
this local effect, the target had evidently received a serious shake: one rib 
was cracked through and bent out, a number of small rivets were broken; 
the plate struck was buckled about ljin. and slightly cracked. The shot 
which rebounded from the target was set up about 2J in., and was of 
excellent material. 
A cylindrical steel shell, with a cast-iron head, made on a principle 
designed by Sir William Armstrong, for the purpose of penetrating iron 
plates by directing the force of the explosion of the bursting charge forward , 
was next fired from the same gun. It weighed 288 lbs., had a bursting 
charge of 11 lbs., and was fired with a charge of 45 lbs. of powder, which 
gave, at 25 yards in front of the target, a velocity of 1320 ft. per second. 
It struck the 5Jin. plate on a part supported by the teak backing. It 
completely penetrated the armour plate, leaving a hole about 14 inches in 
diameter, burst in the teak backing, tearing away the inner skin and 
breaking a rib, and carried a shower of fragments and splinters in board. 
The teak was set on fire by the explosion but easily extinguished, one bolt 
was broken, and other injuries done. 
Altogether, for completeness of penetration and for the destructive effects 
which would have been produced both upon the ship and crew, this 
experiment carries with it great significance. 
After this, a cylindrical flat-headed homogeneous metal shell, weighing 
148 lbs., with a bursting charge of 5 lbs. 12 oz., was fired from the Whitworth 
7-in. gun, with a charge of 25 lbs. of powder, which gave a velocity, at 
30 yards in front of the target, of 1265 ft. per second. This shell struck 
the 5J-in. plate near the hole made by the last Armstrong shell, punched 
out a clean cut hole about 9 inches in diameter, and burst in the teak 
backing; beyond blowing out some of the timber, it added very little indeed 
to the injury done by the Armstrong shell. 
Lynall Thomas* 9-in. gun next missed the target with a round-headed 
solid steel shot, weighing 327 lbs., fired with a charge of 50 lbs. of powder, 
which, at 546 ft. from the gun, gave a velocity of 1220 ft. per second. 
The same gun next fired a wrought-iron solid flat-headed shot, weighing 
302 lbs., with a charge of 50 lbs. of powder; the velocity of this shot was 
not obtained with certainty, it struck partly on the 6J-in. and partly on the 
7J-in. armour; the greatest depth of impression on the latter plate was 
6 in., and on the former 4 in. The 7J-in. plate was cracked through a bolt 
hole and round the indent, as was also the 6J-in. plate; but, altogether, the 
injury done was less than had been expected. 
A hardened steel shot was next fired from the same gun; it weighed 
330 lbs., was round-headed, was fired with a charge of 50 lbs. of powder, 
which gave a velocity of 1220 ft. per second at 25 yds. in front of the target. 
It struck close to the lower edge of the 7J-in. plate, and made an irregular 
indentation measuring about 1ft. by 1 ft..8 in., and 7 in. deep; two bolts 
were broken, one rib broken through, two others much bent, and the skin 
bulged in. The shot itself broke in half lengthways. 
[vol. IV.] 
7 
