 The practice of rifling — casting spiraling lines inside the cannon's barrel — was applied to artillery more frequently by 1855, as it gave cannon gyroscopic stability, which improved their accuracy. One of the earliest rifled cannon was the Armstrong gun — also invented by William George Armstrong — which boasted significantly improved range, accuracy, and power than earlier weapons. The projectile fired from the Armstrong gun could reportedly pierce through a ship's side, and explode inside the enemy vessel, causing increased damage, and casualties. The British military adopted the Armstrong gun, and was impressed; the Duke of Cambridge even declared that it "could do everything but speak." Despite being significantly more advanced than its predecessors, the Armstrong gun was rejected soon after its integration, in favor of the muzzle-loading pieces that had been in use before. While both types of gun were effective against wooden ships, neither had the capability to pierce the armor of ironclads; due to reports of slight problems with the breeches of the Armstrong gun, and their higher cost, the older muzzle-loaders were selected to remain in service, instead. Realizing that iron was more difficult to pierce with breech-loaded cannon, Armstrong designed rifled muzzle-loading guns, which proved successful; The Times reported: "even the fondest believers in the invulnerability of our present ironclads were obliged to confess that against such artillery, at such ranges, their plates and sides were almost as penetrable as wooden ships."
