present high velocity guns it has reached a ratio of about 0·4
of the weight of the projectile.
Fig. 46.
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| Fig. 47.—French Obturator.Fig. 48.—Elswick Cup. |
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| Fig. 49.Fig. 50.Fig. 51. Figs. 49-51.—Broadwell Ring. |
The progress of artillery and the improvements made in armour have been reciprocal; as the protective value of iron and subsequently of steel plates has increased, so the penetrative force or quality of the projectile has advanced. Often, after a period of apparent inactivity, fresh ideas or new metallurgical processes have enabled further progress to be made; this is the case at the present time as regards both projectiles and armour. As a matter of fact, armour, at the present-day fighting ranges, is rather ahead of artillery—hence the demand for greater power; but even with this the probability of perforation is small, and is usually only obtained when the projectile strikes normally to the surface of the plate; the chance of this happening in action is somewhat remote. During the Russo-Japanese War no instance of perforation of the thick belt or turret armour is known; the chief cause of the Russian losses was the bursting of 12-in. and 6-in. shells inside the unarmoured portions of their ships; it is stated that no ship survived after being struck by ten 12-in. projectiles.
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| Fig. 52.—De Range Obturator. |
Fig. 53.—Steep Cone de Bange Obturator. |
Some authorities have lately sought to increase the muzzle energy—without adding weight or length to the gun—by increasing the weight of the projectile. This can be done to a limited extent with beneficial results, but it is impossible to carry the idea very far, as the projectile becomes very long and difficulties may be encountered with the rifling; or, if these are avoided, the thickness of the walls of the shell is increased so much that the heavier projectiles is in reality less powerful owing to its internal bursting charge being comparatively small. Again, many foreign gunmakers claim that their guns are, in comparison with English guns of the same power, of less weight. This is true in a limited sense, but such guns have nothing like the same factor of resistance as English guns, or, in other words, the English
