The later developments in naval artillery began with the 12-inch 46-ton wire gun, which was the chief weapon of the battleships between 1894 and 1897. This gun was 37 feet 1 inch in length, or 35.43 calibres, and threw an armour-piercing shell of 850 lb. with a charge of 167½ lb. of cordite. It had a muzzle penetration of 36.8 inches of wrought iron, and was in every respect as powerful as the 13½-inch 67-ton gun, which it replaced. During 1898, the 12-inch wire gun, weighing about 50 tons, was introduced.

The adoption of breech-loading made possible a very rapid rate of firing, even with the heaviest guns. In 1881, the Government, in reply to an invitation it issued for guns to meet certain requirements, received a number of replies from gun-making firms, as did also the French Government at about the same time in reply to a similar invitation. These guns, which became known as quick-firing or rapid-firing guns, were comparatively small weapons, and the Armstrong Company at Elswick, having improved upon them with quick-firers of 4.7 inches and 6 inches calibre, they were adopted throughout the Navy as the secondary armament. Their superiority over those they displaced was such that a battery’s firing power was increased sixfold. An important trial took place on board the Hardy in 1887, when a 4.7 gun was mounted on a centre pivot recoil mounting, the whole weighing 4 tons 12 cwt.; this gun fired ten rounds in less than 48 seconds. Compare this with the firing of the ordinary 5-inch breech-loading gun on the gunboat Mastiff, when ten rounds took 6 minutes 16 seconds.

In rifling some of the guns an increasing twist was given, while in others the twist was uniform throughout the bore. The object of the increasing twist was to lessen the strain upon the gun, as the rotary motion was not started when the projectile was first put into motion, but developed as it moved down the bore. The projectiles were provided with studs which fitted into the grooves. The breech-loading guns on the polygonal system of rifling fired projectiles which were coated with lead fixed on with zinc, so that the bore of the gun was not injured by the rush of gas past the projectile as was the case in the rifled guns in which there was windage. Two systems of breech-loading were designed by Sir W. Armstrong, one being the screw system and the other known as the wedge.

The projectiles invented by Major Palliser were specially designed to penetrate iron armour. Cast iron was found to be smashed against armour, wrought iron was too soft to do any damage, and steel in those days was too expensive to be of use. Major Palliser solved the difficulty by making his projectiles of chilled iron, and giving them a cylindrical shape with the pointed or ogival head.

PROJECTILES AND CHARGES USED IN THE BRITISH NAVY.

Photograph by Stephen Cribb, Southsea.

1. Projectile, 16·25 B.L., 1,800 lbs.9. Projectile, 7·5 B.L., 200 lbs.17. Projectile, 4-in., 25 lbs.
2. Charge for ” ” 960 lbs. powder.10. Charge for ” ” 77½ lbs. cordite.18. 4-in. Cylinder.
3. Projectile, 13·5 B.L., 1,250 lbs.11. Projectile, 6-in. B.L., 100 lbs.19. Projectile, 12-pounder.
4. Charge for ” ” 187½ lbs. cordite.12. Charge for ” ” 29 lbs.20. 12-pounder Charge.
5. Projectile, 12-in. B.L., 850 lbs.13. Projectile, 5-in. B.L., 50 lbs.21. 12-pounder Case Shot.
6. Charge for ” ” 211 lbs. cordite.14. Charge for ” ”22. 12- ” 8 cwt. Charge.
7. Projectile, 9·2 B.L., 380 lbs.15. Projectile, 4·7, 45 lbs.23. 6- ” Cartridge.
8. Charge for ” ” 103 lbs. cordite.16. 4·7 Cylinder for Cartridge.24. 3- ” ”
25. 1¼-lb. Cartridge.

Experiments are often carried out to ascertain the resisting qualities of various combinations of armour offered to projectiles of varying weights and penetrative powers according to the distances at which they are fired. When iron was used for armour-plating, targets were built in duplication of those provided for the armoured ships. Both the Armstrong and Whitworth 70-pounders fired in the competition trials over 3,000 rounds, or three times the number assigned as the limit to the life of the old cast-iron smooth-bore guns. Of course, the bigger the gun the shorter the life, as a rule.

The French adopted for naval service four different patterns of heavy breech-loading rifled guns, all made of cast iron, and strengthened behind the trunnions with steel rings which were shrunk on. Their weight varied from 21 tons 13 cwt., with a calibre of 10.82 inches, to the gun of 4 tons 18.5 cwt., with a calibre of 6.48 inches, firing projectiles respectively of 476 lb. and 99 lb. The weight of the charge was rather more than one-sixth of that of the projectile. The guns were mounted on wrought-iron carriages and slides constructed on the box girder system.