In 1817 percussion caps were invented in the United States, but some time elapsed before they were introduced into military use; and though the “percussion rifle” was known in 1841, the victorious troops which went with Scott in the brilliant campaign from Vera Cruz to the City of Mexico, six years later, were armed with the flint-lock musket. In 1833, Colonel Colt invented the first practical revolving pistol. This weapon, especially in its present perfected form, is so well known as to need no description. The first pattern of Colt’s revolver used paper cartridges and percussion caps. In the long period of peace which Europe enjoyed after the battle of Waterloo, but little change was made in the organization of the armies of the great powers; and in the Crimean war (1855–56) the composition of the English, French, and Russian armies did not differ materially from the constitution of the forces of the same nations in the Napoleonic wars. Marked changes had, however, been made in the nature of the weapons; most of the English and a part of the French infantry being armed with the rifle, though the Russian infantry, with the exception of a few selected regiments, were still armed with the smooth-bore musket. Though the extreme range of the rifle at this time did not exceed eight hundred yards, and was inaccurate at half that distance, it was, nevertheless, a formidable weapon in comparison with the infantry musket of Napoleonic times. Rifled siege guns were employed by the British at Sebastopol, but they were not a success, and were soon withdrawn from the batteries. A striking indication of the increased range of artillery was furnished at Sebastopol, when the besiegers established their first parallel at a distance of 1300 yards from the Russian works. [Illustration: ARMSTRONG FIELD GUN.] In the Italian war of 1859 rifled cannon appeared for the first time upon the field of battle. They were employed by the French, and to their use was largely due the victories of the French and Sardinians over the Austrians. For many years the attention of artillerists had been devoted to the production of serviceable rifled artillery, and as early as 1846 an iron breech-loading rifled cannon had been invented in France by Major Cavalli. This gun fired a shell not dissimilar in shape to the projectile employed in the Minié rifled musket. In 1854, experiments with a Cavalli gun gave very satisfactory results, both in range and accuracy; but the breech mechanism seemed dangerously weak, and the rifled guns, adopted by the French and used with such effect in Italy, were muzzle-loaders.