578 



NAVIES OF EUROPE. 



fused metal is poured in, and, after cooling, the 

 gun is shaped, rifled, and finished. Armstrong 

 obtained the following results with his wire 

 gun : Caliber, 10-236 inches ; weight, 21 '5 tons ; 

 projectile, 500 pounds; charge of powder, 300 

 pounds ; pressure in chamber, 18'6 tons. The 

 relation between the charge and the projectile 

 is here enormous, the former being over one 

 half the latter. 



THREE TYPES OF GUNS. Authorities on im- 

 proved ordnance are advocating three types of 

 guns, all, however, being steel breech-loaders. 

 For armor-piercing, it is said, a long, pointed 

 bolt, nearly solid, is required, which must strike 

 with great velocity, and must, therefore, be 

 propelled by a very large charge of powder. 

 Hence, an armor-piercing gun should have a 

 large chamber and a comparatively small bore 

 of great length. For pieces intended for breach- 

 ing fortifications, on the other hand, no en- 

 larged powder-chamber is wanted, but the 

 shell must be made to hold the most powder 

 for a given weight, and therefore must be 

 rather short and thick. Hence the bore of 

 the gun must be large, and need not be long, 

 as little velocity is required. For producing 

 destructive effects among troops a third kind 

 of projectile should be employed namely, 

 shrapnel. For the effective discharge of this 

 missile a large powder-charge is necessary, 

 while, as the shell has to hold as many bullets 

 as possible, the bore must be large enough to 

 contain a short projectile of the given weight. 

 Thus the proportions of the shrapnel-gun were 

 intermediate between those of the armor-pierc- 

 ing gun and of the shell-gun. 



EXPERIMENTS AT SPEZIA. Some very inter- 

 esting experiments were made at Spezia, Italy, 

 in the latter part of November, for the purpose 

 of testing the resistance of armor-plates, and 

 the perforating or crushing power of heavy 

 ordnance. The primary object was to ascer- 

 tain by competitive trial the comparative merits 

 of the compound plates of Cammell & Co. 

 and Brown & Co., of Sheffield, England, and 

 the all-steel plates of Schneider & Co., of 

 Creusot, with a view to providing the most 

 effective armor for the monster ships, the Italia 

 and the Lepanto. The scene of the trial was 

 the polygon of Muzziano, at Spezia, where 

 similar experiments took place in 1876. On 

 that occasion the Creusot establishment had 

 carried off the palm, and the Duilio and Dan- 

 dolo had in consequence been armored with 

 Schneider plates ; but the English manufactur- 

 ers proceeded to make improvements in their 

 plates by covering an iron backing with a face 

 of steel. It was claimed for these compound 

 plates that they were superior to those made 

 wholly of steel. But the Messrs. Schneider 

 had also made improvements in their work, 

 and before ordering the armor for its new ves- 

 sels the Italian Government determined to 

 make a new trial at Spezia. 

 ^ The cut on page 579 represents the gun in po- 

 sition as used at the experiments at Spezia. It 



is not mounted in a turret, but on a pontoon 

 built for the purpose. It was loaded and 

 worked, however, by the mechanism to bo 

 used in the turret described further on, and 

 precisely as it will be on board ship. 



In the left-hand corner is represented the 

 missile before the first shot at the Schneider 

 plate. In the right-hand corner is represented 

 the same missile after the shot. 



The cut on page 580 represents the three 

 targets after the first and second fire at Spezia. 



The Cammell, the Brown, and the Schneider 

 plates, each 11 feet long, 8f feet broad, and 19 

 inches thick, and weighing about 32 tons, were 

 severally bolted, according to the methods of 

 the competing manufacturers, to a heavy back- 

 ing of oak and old metallic targets. These 

 were set up at a distance of a little less than 

 100 yards from a 100-ton muzzle-loading Arm- 

 strong gun, which was anchored in a huge 

 float off the shore. Two shots were fired at 

 each plate, the first with a charge just suffi- 

 cient to perforate 19 inches of iron, and the 

 second with a charge capable of perforating 

 24 inches of iron. These were respectively 

 328 and 478 pounds of Fossano powder. The 

 projectiles used were from the San Vito Arse- 

 nal, and were of pig-iron from the Gregorini 

 foundry, weighing 2,003 pounds each. The 

 caliber of the Armstrong gun used was little 

 less than 18 inches. The striking velocity 

 the shot in the first test was 1,220 feet p( 

 second, and the total energy 20,000 foot-toi 

 In the second test the striking velocity w* 

 1,560 feet, and the total energy 33,900 foe 

 tons. At the first shot both the English plat 

 were badly cracked. The projectile pei 

 trated the Brown plate 14 inches, and brol 

 off. The Cammell plate was penetrated 

 inches. In both there were numerous cracks 

 some of which extended clear through, whil 

 the backing was badly wrenched, and 

 frames and bolts broken. The Schneider plat 

 was penetrated eight inches, but was left 

 solutely without a crack, and its frame ai 

 backing were intact. At the second shot hot 

 the English plates were shivered to fragmenl 

 which fell at the foot of the target, leavii _ 

 the backing bare and badly shattered. Of the 

 Cammell plate this was literally true, and only 

 a single piece of the Brown plate was left 

 clinging to the target by a broken bolt. The 

 Schneider plate was penetrated nine inches, or 

 less than half its thickness. It received a few 

 insignificant cracks, but the backing was unin- 

 jured, and not a bolt was broken. The pro- 

 jectile itself was badly shattered. The Gov- 

 ernment commission, as a result of the ex- 

 periment, awarded the palm of superiority to 

 the Schneider plate, which was then subjected 

 to a crucial test. It was attacked at point- 

 blank range with the same high powder-charge, 

 and great velocity used in the second competi- 

 tive trial, and with the hardest projectiles 

 made. The striking velocity in this case was 

 1,538 feet per second, and the total energy 



