ARMOUR AND ITS ATTACK BY ORDNANCE. 
105 
guns. For example, if the oscillation or vibration of the guns fixed 
in the hoods had affected the practice, there would have been a valid 
cause of objection. This was not the case, and errors in setting fuzes 
or time lost in getting the exact range do not concern us. In con¬ 
clusion the most remarkable design and features exhibited may be 
repeated :—(1.) Simplicity, efficiency, and speed of the quick-fire 
gear. (2.) The power of the quick-fire field guns when the recoil was 
checked. (3.) The nave brake employed. (4.) The power of heavier 
guns on naval mountings, where automatic recovery took the place of 
non-recoil. (5.) The behaviour of the movable shielded mountings 
dragged by horses, and got in and out of gun pits. (6.) The erection 
of the heavier shield and gun mounting in If hours. (7.) The be¬ 
haviour of the heavier guns in the hoods or cupola tops, which were 
held on a centre pivot and rested loosely in their surrounding glacis or 
other rings. 
Spezia Turrets and Krupp and Armstrong Heavy Guns. 
The two turrets for the defence of Spezia harbour, 1 2 each mounting 
two Krupp 119-ton guns, were completed in 1891. The total running 
weight of each is 2050 tons. The armour is of Gruson's chilled-iron, 
proved in 1886, as before stated. The carriages and working gear 
was supplied by Elswick. A cupola turned a complete revolution in 
1 minute 45 seconds, using a single engine out of the four provided 
for it. These turrets are by far the most powerful erections of their 
class yet made. It is stated that the 119-ton guns at Meppen have 
achieved on one occasion a muzzle energy of 57,950 foot-tons or 488 
foot-tons per ton of gun. The Elswick 111 (or 110^) ton gun has 
achieved 57,630 foot-tons, or 519 foot-tons per ton of gun. The 
charge at Spezia for the Krupp gun is 300 kg. (661 lbs.), the projectile 
weighs 920 kg. (2240 lbs.), the muzzle velocity is 1821 f.s., and the 
consequent energy 46,630 foot-tons. The service tables give for the 
Elswick 111-ton gun, a “ full charge” of 960 lbs. S.B.ca. The 
projectile weighs 1800 lbs. The muzzle velocity is 2087 f.s., and 
energy 54,390 foot-tons. It appears then from the above that Krupp 
has on one occasion obtained greater energy than Armstrong, but it 
is difficult to say how far each gun is strained in the effort to obtain 
great energy. It may be questioned if the makers know it themselves. 
The service achievement at Spezia is modest compared with that of the 
Armstrong fired with the full charge, but the former may be intended 
for more habitual use than the latter. It may be briefly said that the 
111 and 119-ton guns are of about the same power, the latter ought 
not to be stronger than the former, because the Krupp wedge system 
wastes a large mass of metal at the breech. 
Perforation Trials at High Velocities to Test Formula. 3 
Most British and foreign formulae give perforations which agree 
1 See “ Brassey’s Annual,” 1891.and 1892, 
2 The author’s attention was called to this subject when dealing with results calculated for very 
high velocities communicated to him by Canet, Krupp, and Armstrong. In consequence he has 
endeavoured to induce authorities, British and foreign, to investigate the question. 
