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Teach PA History
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Digging, Smelting and Forging: But Why in Pennsylvania?
Background Information for Teachers

Pennsylvania's Natural Resources

In a 1681 invitation for people to migrate to his province, William Penn describes Pennsylvania in geographical detail and lists both prevalent natural resources as well as their potential products. Among a list of flax, silk, hemp, wine, cider, tobacco, and other products, Penn notes iron as "a Commodity the Country is Thought Capable of". Penn's accuracy of iron's potential in Pennsylvania has played out in history perhaps even more significantly than Penn himself could have imagined. By 1759 a gentleman named Israel Acrilius writing on the colonies declared Pennsylvania to be the most advanced in their iron industry. And over a century later, Pennsylvania was still leading the manufacture of iron. One of the factors Penn most surely considered in his list of potential Pennsylvania commodities was the availability of natural resources needed to make them. Pennsylvania proved a prime location for the iron industry due to its abundance of the necessary natural resources required for iron making. Pennsylvania had natural iron ore deposits, vast forests providing wood that was made into charcoal to fuel early furnaces, coal beds of bituminous and anthracite coal which eventually replaced charcoal as fuel for furnaces, limestone used as a flux (to draw away impurities from the iron ore), and streams and water beds that offered water power for the furnaces. Indeed, Pennsylvania had all of the necessary components required for a growing iron industry. However, natural resources alone cannot account for the tremendous iron industry in Pennsylvania…

The Market for Iron and Iron Products

Iron was an essential part of the growth and development of the state of Pennsylvania and the colonies. Prior to the existence of iron making in Pennsylvania, iron products were imported from Britain. With the increasing population and demand for iron products, enterprising individuals sought ways to produce iron and iron products with the natural resources in the colonies rather than resort to costly importation. One can only imagine the colonists were grateful for an understanding of iron making from Britain, even–or especially–as they manufactured cannons and cannonballs to break away from her. Early furnaces emulated those from Britain, but as workers began to develop their own experience with iron manufacturing, new technologies in iron production improved the efficiency of iron making in Pennsylvania.

Iron was used importantly to help this land become a young nation. But why was Pennsylvania still producing an increasing amount of iron and iron products in the nineteenth century? The improvement of transportation provides one component to the answer. With the expansion of the canal systems in the early 1800s and subsequent creation and growth of the railroads, there was a more efficient way of transporting goods throughout the state. As the population in Pennsylvania and the northeast increased, there was also an increased demand for iron products. These advances in transportation and the rise in population led to an increased number of furnaces and forges throughout the state of Pennsylvania. Iron was the most durable and strongest material up until the mass production of steel. It was therefore used to make a number of products required for a growing agricultural and industrial nation. Products made from iron included tools for farmers and blacksmiths, wheel rims for wagons, and rails for the railroad system.

The Process of Smelting and Forging Iron

The process of smelting iron began with combining several of the natural resources in a furnace. Limestone and iron ore were poured down what is called a "charging hole" and combined with a fuel source. (Manufacturers experimented with finding the most efficient fuel source. Therefore, charcoal gave way to bituminous coal, to coke, and finally to anthracite coal as fuel for furnaces.) Early blast furnaces were like big ovens inside which the temperature needed to reach 2600 F to 3000 F to create the molten iron. In order to increase the temperature inside the furnace, the early blast furnace had a water wheel which powered the bellows to blow or "blast" air into the furnace. Adding air or oxygen to the fire raised the temperature. Inside the furnace the limestone combined with the impurities in the iron ore to create slag, the waste product of the materials that formed as a layer on top of the molten iron. The founder was the person responsible for determining when the iron was ready, that is, when the furnace was "ready to tap." With his word the molten iron was released from the furnace. The slag ran off the top, and the molten iron ran down into a gutter called the "pig bed" to cool. The cooled iron was taken to a forge where it was reheated and hammered to create wrought iron which was then fashioned into various products.

The below listed website will help to explain the process before teaching the lesson. Included is a nice link to a BBC animation of how a blast furnace works (also used in the procedure section of this lesson). You may wish to preview it before class: How Stuff Works: BBC: The British Victorians: The Blast Furnace Animation. (See weblink below.)

Related Marker Pages
markerColebrookdale Furnace Marker Page

This marker page will provide detailed information about the smelting process. By reading this marker page, you will have the background information necessary to explain the process of smelting and forging iron to your students.

Web Sites

How Stuff Works: BBC: The British History Victorians: The Blast Furnace Animation http://science.howstuffworks.com/framed.htm?parent=iron.htm&url=http:/...

This website provides a visualization of how a blast furnace actually works. It shows step by step what each part of the furnace does in order to change the iron ore into molten iron. There is also an activity that allows the student to use their knowledge and memories to create their own furnace. It offers a great visual representation of the iron smelting process.

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