THE DEVELOPMENT OF ABMOUB. 
467 
but not sufficiently to break the shot point. In other cases the faces 
broke the shot points when the velocity reached about 1,600 f.s. The 
contrast between the Vickers plate and the St. Chamond deserves 
notice. At 1,640 f.s. velocity the shot which had hitherto penetrated 
deeper in the former plate broke up with 2*1 in. penetration, while it 
got nearly through the St. Chamond plate. Two extra rounds were 
fired at the Vickers with low velocities, which again entered deeply 
because the points did not break, for though in round six the shot broke 
into three pieces it was not the characteristic smashing into fragments 
which took place at higher velocities. Vickers plate alone kept all 
shot out, it was, however, cracked or broken through in more than one 
direction. The calculated perforation of the fifth round is 10*8 inch 
of iron. The lesson to be learned from this trial is that to break the 
shot points and so defeat it; the face must be very hard and the strik¬ 
ing velocity over about 1,600 f.s. 
In the autumn of 1893, a competition took place at Pola for the Pola com- 
Austrian Government, for plates 7*87 ft. x 5*9 ft. x 10*6 in., 
attacked by the 15 c.m. (5*9 in.) gun firing four steel 112*4 lb. shot 
striking with about 1980 f.s. velocity. A fifth round to be fired at the 
centre with a steel 24 c.m. (9*4 in.) shot of 474 lbs. with a velocity of 
1417 f.s. The calculated perforations of these would be 14*0 and 15*4 
inches of iron. To this trial Dillingen, Vickers, Cammell and Witkowitz 
sent nickel steel plates unhardened, and Vickers and Krupp, plates 
with hardened faces. The Vickers Harveyed plate and the Witkowitz 
plates only, were considered to have kept out the smaller shot. The 
former was fractured by the heavy shot; the latter kept it out with¬ 
out fracture and was therefore preferred. 
During the latter part of the year, good Harveyed 10£-in. plates 
made by Cammell and Brown were tested at Shoeburyness. 
In the end of the summer, a Schneider nickel steel plate, 8 ft. x 
8 ft X 15*9 in. for the Russian ship Tria Sviatitelia , was attacked by 9*4 
Holtzer steel shot weighing 317 lbs., with velocities from 1,948 to 
2,001 f.s. The greatest penetration was 14*1 inches. The projectiles 
broke. The calculated maximum perforation is 19*7 in. of iron. 
In the Chicago Exhibition, Krupp exhibited a nickel steel plate Krupp 
with a hardened face, 8 ft. X 6 ft. x 10*23 in., weighing about 9 tons, at 
which had kept out a very heavy attack, including one 8*26 gun shot lcafi:0 ‘ 
weighing 307*54 lbs., striking with 1,825 f.s. velocity and 7,096 foot 
tons energy, implying a calculated perforation of about 18 in. of iron 
and 788 foot tons energy per ton of plate. 
On March 15th, at the institution of Naval Architects, Mr. C. E. C. E. Ellis 
Ellis, of Brown’s, Sheffield, read a valuable paper on armour, in which on 
he gave a large series of results. He estimated that plates then made 
with heated faces had 50 per cent, more resisting power than their 
untreated predecessors of 1888. Up to this time nickel had not been 
adopted in England, owing to difficulties in treating it, and in drilling 
holes in hardened faces of nickel plates. Plates without nickel had 
proved at least equal to nickel plates in resistance to perforation, in 
trials in England at this time. 
