(Iron and Steel in America: Early Foundations by W. David Lewis)
Lewis argues in his article that the United States originally used minimal iron compared to Europe, but as colonialization increased in the colonies so to did iron requirements. Almost everything was made out of wood in the 1600s and 1700s. Boats, wagons, tools, homes, wheels, machine parts and screws were all wood but iron proved to be better for all of these purposes. Iron was used and required in guns, armor, tires, roofing, railroads, horseshoes, cutlery, swords, tool edges and plow heads, and more. Iron became increasingly demanded upon as the colonies expanded.
In the British colonies producers of wrought and pig iron used bloomeries because the iron masses produced were called bloom. While bloomeries were easy to set up they were small-scale in operation, this limited production. For larger scale operations a blast furnace was required. These were heftier to build and made of stone 25’ high in a pyramid shape, then layered in clay and layered again with more stone. A hole in the top called the “throat/tunnel head” opened up to the “bosh” which served as funnel into the “crucible” where iron was melted. A small hole near the bottom “tuyere” is where a bellow forced oxygen into the fire. The “hearth” at the bottom served as a drain and was blocked with a “damstone” until the white-hot iron was ready to pour out into sand molds. This was called “pig iron.” Limestone and charcoal fed into the furnace to act as fuel and a bonding agent for impurities.
Lewis continues to expand on the need for iron in the early United States and gives figures on its production through the 18th century. The pig iron was either sold, refined into wrought iron or steel. The US increased from 1,500 tons of iron produced in 1700 to 210,000 tons by 1775. What this means for the American people is that they desired higher quality tools, machines, vehicles, and several areas of the country structured their economies around the iron industry like Appalachia. This impressive feature of copying Old World techniques and then exponentially increasing production is a testament to the pioneering attitudes of Americans.
I liked Lewis’s use of national production figures and so I found an article from the USGS on the current (2015) global production of iron now. The article interestingly goes into detail on how there is controversy today on how to measure iron output per nation. There are multiple ways of measuring either iron ore dug from the ground, which is often unusable and usable iron ore that is qualified for global market use. The biggest controversy is comparing Chinese iron production with the rest of the world. China’s difference in measuring iron ore production has actually led to a global overestimate of mined iron that the USGS is now trying to refigure and correct. I also found an interesting page on coal and iron usage and production in Appalachia, which has a lot of great pictures to help understand how these furnaces, iron objects and tools, and mining processes worked.