From The Art and Popular Culture Encyclopedia
Puddle iron is a type of wrought iron, used mainly in construction. Its production process was invented at the end of the eighteenth century, following an increase in the need for wrought iron. It is produced in a puddling furnace. The process results with an iron that contains a slightly increased carbon content compared to wrought iron. This provides it with a higher tensile strength. The puddling furnace also allows a better control of the chemical composition of the iron. The Eiffel Tower was built with puddle iron for a large part of its structure, as was the framework of the Statue of Liberty. Other standing structures such as bridges also used puddle iron.