In 1814 Joshua Shaw of England invented the percussion cap. Thus, by the invention of the percussion principle by Forsyth, and that little copper cylinder of Shaw, having a flake of fulminating powder inside and adapted to fit the nipple of a gun and be exploded by the fall of the hammer, was sounded the death knell of the old flint-locks with which the greatest battles of the world had been and were at that time being fought. The advantages gained by the cap were the certain and instantaneous fire, the saving in time, power, and powder obtained by making smaller the orifice through which the ignition was introduced, and the protection from moisture given by the covering cap. And yet so slow is the growth of inventions sometimes that all Europe continued to make the flint-locks for many years after the percussion cap was invented; and General Scott, in the war between the United States and Mexico in 1847, declined to give the army the percussion cap musket. The cap suggested the necessity and invention of machines for making them quickly and in great quantities. The celebrated “Colt’s” revolver was invented by Colonel Samuel Colt of the United States, in 1835. He continued to improve it, and in 1851 exhibited it at the World’s Fair, London, where it excited great surprise and attention. Since then the revolver has become a great weapon in both private and public warfare. The next great inventions in small arms were the readoption and improvement of the breech-loader, the making of metallic cartridges, the magazine gun, smokeless powder and other explosives, to which further reference will be made. To return to cannons:--In 1812 Colonel Bomford, an American officer, invented what is called the “Columbiad,” a kind of cannon best adapted for sea-coast purposes. They are long-chambered pieces, combining certain qualities of the gun, howitzer and mortar, and capable of projecting shells and solid shot with heavy charges of powder at high angles of elevation, and peculiarly adapted to defend narrow channels and sea-coast defences. A similar gun was invented by General Paixhans of the French army in 1822. The adoption of the Paixhans long-chambered guns, designed to throw heavy shells horizontally as well as at a slight elevation and as easily as solid shot, was attended with great results. Used by the French in 1832, in the quick victorious siege of Antwerp, by the allies at Sebastopol, where the whole Russian fleet was destroyed in about an hour, and in the fight of the Kearsarge and the doomed Alabama off Cherbourg in the American civil war, it forced inventors in the different countries to devise new and better armour for the defence of ships. This was followed by guns of still greater penetrative power. Then as another result effected by these greater guns came the passing away of the old-fashioned brick and stone forts as a means of defence.