Improvement in gun barrels depends on the iron--Continental manufacturers advance while English stand still--Cheap and inferior guns of “Park-paling”--Scarcity of horse-nail stubs--Importance of iron manufacture--Great value of steel in ancient times--Iron originally made with wood charcoal--Coal coke unfit for making best iron--British iron ore inferior--Mr. Mushet on steel-iron--English workmen employed abroad--English gun-makers’ names forged in Belgium-- Indian Iron and Steel Company--Indian process of making steel--Hammer- hardening recommended--Difference of “Silver steel” and “Twist steel” --Method of making laminated steel--It is spoilt by over-twisting-- Watering of Damascus barrels--Proportions of carbon in steel and iron --Damascus barrels often plated--Modern method of making Damascus iron (with cuts)--Objection to wire-twist iron--Figured barrels--Damascus barrels made in Belgium--Damascus iron inferior in strength--Use of old horse-shoe nails for gun-barrels--Stub iron alone insufficient-- Prejudices of provincial gun-makers--Mixture of steel and stub iron-- Importance of welding on an air furnace--Proportions of steel and stub iron--Efficacy of hammer-hardening and reworking iron--Improvements in superior iron owing to gun-makers--Explosions of steam-boilers owing to neglect or bad construction--Boiler iron improveable--Steel- Damascus barrel iron--Manufacture of “charcoal iron”--Imitation of “smoke brown”--Gains from using inferior iron--Frauds in barrel making --Advice of Edward Davies in 1619--“Threepenny skelp iron”-- “Wednesbury skelp”--Test of a safe gun--“Sham damn skelp”--Base guns made to sell--Their injurious effect on the gun-making trade--“Swaff- iron forging.” 146 CHAPTER V.--GUN-MAKING.