“Early Iron Making in America” by Lewis discusses the reason iron making began in colonial America and how colonial Americans made iron. In the early colonial days, almost all tools were mad of wood except for parts that needed to be used for cutting or striking. Machines like water wheels, gears, and spinning wheels were also made from wood. However, wood was not the optimal material for these jobs, mainly because wood would easily wear down over time due to friction. Iron could be made in small quantities by the colonists and they used it in cutting tools, kitchen equipment, and weapons. Because they had some experience with iron, the colonists knew it was more durable than wood.
The first way colonists produced iron was through the use of a bloomery. The bloomery was a primitive method of making iron that required very little equipment. The process started with taking chunks of iron ore and heating it in a stone hearth with charcoal and a bellows to circulate air. This would produce a spongy mass of iron that would be hammered and reheated to purify the iron, creating a type of iron known as wrought iron. The wrought iron was very versatile and could be shaped into nearly any tool or weapon. The demand for the skill of working a bloomery was so high compared the supply of people with the skill that bloomery workers in Virginia charged such exorbitant prices for their services that county courts had to regulate prices to a point where iron was affordable.
The biggest limitation of producing iron via a bloomery was the low quantity of iron it was able to produce. The bloomery usually produced enough iron for local blacksmiths, but not enough for the large and expanding market and its high demand for iron. This shift in the market caused a transition from the bloomery to the blast furnace. Unlike the bloomery, the blast furnace was not a simple structure. The blast furnace was 25 to 30 feet tall made from layers of stone and clay. Iron ore was smelted inside using charcoal due to its high burning temperature, limestone was added to remove impurities, and bellows would blow air in through a small hole called a tuyere to further increase the temperature. The liquid iron would then drain down into a part of the furnace called the crucible. Once all the iron had melted, a hole would be unplugged and the iron would flow into sand molds. This iron produced by blast furnaces became known as pig iron because the molds around thee furnace resembled a litter of pigs nursing from a mother sow. Iron from blast furnaces could also be cast into other shapes such as various pots and pans.
For most purposes in the colonial era, wrought iron and pig iron worked just fine. However, a few things such as sword, cutlery, and clock and watch springs needed a stronger alloy, steel. This steel could be created through baking strips of iron and charcoal dust in a clay vessel for up to 11 days. Even after this long process, only the outer layer of the iron would be infused with carbon, so the core of the steel strips would still be iron.
Written by G. Morris. Word count: 537(without header or captions)