“ During the Crimean War, Armstrong was employed by the War Office to make explosive apparatus for blowing up the ships sunk at Sebastopol. This led him to devise the form of cannon which bears his name. The essential feature of the Armstrong gun, whether rifled or smooth bore, breech-loading or muzzle-loading, is that the barrel is built up of successive coils of wrought-iron, welded round a mandrel into a homogeneous mass of great tenacity, the breech being especially strengthened on similar principles. ”