Their adoption into almost every service, with the consequent development of horizontal shell fire, was beyond question the most important event in the history of artillery since Gribeau-val's time, and eventually led to the adoption of iron armor as a protection for vessels of war. The first instance of the employment of this kind of fire on a large scale was at the siege of Antwerp by the French in 1832, where it proved so formidable that the defence were able to make but a feeble resistance. At Si-nope, where the whole Turkish fleet was demolished in about an hour by the Russian shells, at Sebastopol, as well as in the more recent naval combat between the Kearsarge and Alabama, Paixhans's predictions as to the destructive effects of heavy shells have been completely verified. The French field materiel was modified in 1827 by the substitution of 32 and 24-pdr. howitzers, lengthened to correspond with 12 and 8-pdr. guns, for the 6-inch howitzer and 4-pdr. gun, which were abolished; the limber of the gun carriage was subsequently lightened and provided with an ammunition chest, its wheels being made of the same size as those of the carriage; the mode of connecting the limber with the carriage was also simplified, so as to greatly facilitate the manoeuvres of limbering and unlimbering; while the two flasks which formed the trail were replaced by a single piece called the stock, which permitted the carriage to turn in a smaller circle than before.

In 1850 a light 12-pdr. gun devised by Louis Napoleon, and known as the gun-howitzer or Napoleon gun, was experimented upon in France. The object chiefly aimed at in its construction was the substitution of a single gun of medium weight and calibre, firing both shot and shell, for the 12 and 8-pdr. guns and 32 and 24-pdr. howitzers. The new piece, giving very favorable results, was issued in 1853 to the divisional batteries, taking the place of the 8-pdr. gun and 24-pdr. howitzer, the heavy 12-pdr. gun and 32-pdr. howitzer being temporarily retained in the reserve artillery. It was most successfully used by the French during the Crimean war, and was adopted into various European services as well as into that of the United States. - In England the drivers1 corps was abolished in 1822, and men were enlisted for the royal artillery both as cannoneers and drivers; the troops of horse artillery, however, continued to have drivers specially enlisted for that purpose, and to this very faulty system the mounted batteries have reverted since the Crimean war. In 1827 three field batteries were organized, each having four pieces and 45 horses.

The British artillery continued in a very imperfect state up to 1848, a mistaken notion of economy having kept it insufficiently supplied with guns and horses. At that date, as well as in 1832, it was largely increased and placed on a better footing. Each battery now consisted of four guns and two howitzers; the armament being improved by the substitution of 24-pdr. and 12-pdr. howitzers for the old 5 1/2-inch howitzer, by the introduction of the 32-pdr. howitzer, and by the practical abandonment of the heavy 6-pdr. and 3-pdr. guns. The ammunition, particularly the shrapnel, was also made more efficient by the adoption of Captain Boxer's fuse. At Sebastopol in 1854 the English siege pieces consisted of 32 and 24-pdr. guns, 10 and 8-inch shell guns, and 13, 10, and 8-inch mortars. To these were joined 68-pdr. guns borrowed from the fleet, then thought of enormous size; some of them were fired as many as 4,000 times, with a charge of 16 lbs. of powder and with great rapidity. The calibres of the French siege cannon did not materially differ from those of their ally. - The artillery improvement of the other European powers was steadily maintained during this generally peaceful era, and the importance of the arm continued to be felt in the few campaigns which took place.

In the Polish war of 1831, as well as in the Hungarian campaign of 1849, the Russians embraced every opportunity for the employment of artillery in mass. At Warsaw the concentrated fire of a large number of guns decided the success of their coup-de-main and put an end to the resistance of the Poles; the loss in the Russian artillery was however very severe, the killed alone amounting to 40 officers, 400 men, and 800 horses. On the other hand, at Inkerman in 1854 the Russian attack failed on account of the unskilful handling of their artillery masses. The principal large calibres of Russian cast-iron guns at the siege of Sebastopol were 120 (shell), 96, 56, and 40-pdrs. In Belgium the invention (1835) of a new fuse by Gen. Bormann gave case shot an importance and utility hitherto unknown; while iron came into general use throughout Europe for heavy gun carriages. - The systems of field and siege artillery in the United States were chiefly derived from those of France. After the war of 1812 with Great Britain the artillery arm was almost entirely neglected; no field batteries were kept up, and the heaviest gun mounted on the seacoast in 1820 was a 24-pdr. About 1839 Secretary of War Poinsett caused field batteries to be organized, which, though few in number, were brought to a high state of efficiency and rendered valuable services during the Mexican war (1846-8), particularly at Buena Vista, Feb. 22, 1847, where they saved the day.

The columbiad, a long-chambered piece capable of projecting shot and shell at high angles and with heavy charges, was invented by Col. Bomford and used during the war of 1812; a similar gun (Paixhans), as we have already seen, was afterward introduced with great success in Europe. In 1844 the columbiad was lengthened and made heavier to enable it to stand an increased charge of one sixth of the weight of the solid shot; but not proving strong enough, even with these modi-fications, in 1858 its use was restricted to shells, a new gun of improved model taking its place. Wrought-iron carriages for heavy guns were about this time introduced into the United States, and great care was taken in the selection and treatment of American iron, some of which is specially adapted to gun fabrication. About 1847 Gen. Rodman developed his now universally adopted theory of initial tension - in other words, of such a disposition of the metal that when the gun is at rest the interior parts are in a state of compression, while the exte-rior are in a state of tension; this adds great-ly to the strength of the metal, the outer lay-ers being thus forced to stand more and the inner layers less than would otherwise be the case when the gun is fired.