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Cornwall Iron Furnace, Cast House, Bridge House, and Engine House

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c. 1739–1742; 1846 rebuilt; 1856–1857. Boyd St. and Rexmont Rd.
  • Cornwall Iron Furnace, Cast House, Bridge House, and Engine House (© George E. Thomas)

The centerpiece of the Cornwall Iron Works is the oddly rustic furnace with pointed Gothic windows set in carefully cut brownstone walls, as if Hobbits had tried their hand at the industrial culture that J. R. R. Tolkien disdained. The Cornwall furnace may well have been the source for much of the architectural character of Henry Mercer's museum in Doylestown (BU43). Buildings were erected on the site beginning in the 1740s, but the present building reflects the reconstruction of 1846 when the furnace was adapted to steam-powered operation. The main stack was reconstructed in 1856–1857. The hillside site permitted a gravity-fed system, not unlike the nearby Pennsylvania barns, in which loads of ore and lime were brought into the upper levels of the complex to be loaded into the furnace. Here the introduction of forced air (the blast) through a bellows powered first by water and later by steam intensified the heat that transformed the ore to molten iron that flowed into pig iron in molds at the base of the furnace. The iron was then carted away from the cast house to be worked in other forges and foundries. Like contemporary machinery, each part of the complex has its own architectural form that conveys something of its purpose. With the coal house and carpenter and blacksmith shops, the site was largely self-contained. At the peak of its use, three railroads hauled ore, charcoal, and finished castings to and from the foundry. The charcoal-fired complex was unable to compete with the hotter and more efficient anthracite operations of western Pennsylvania and closed in 1883. It remained under the care of the Coleman family into the 1930s when they gave it and an endowment to the state that continues to operate it as a museum. A tour of the furnace should include other Coleman projects in the immediate vicinity.

Writing Credits

George E. Thomas


What's Nearby


George E. Thomas, "Cornwall Iron Furnace, Cast House, Bridge House, and Engine House", [Lebanon, Pennsylvania], SAH Archipedia, eds. Gabrielle Esperdy and Karen Kingsley, Charlottesville: UVaP, 2012—,

Print Source

Cover: Buildings of PA vol 2

Buildings of Pennsylvania: Philadelphia and Eastern Pennsylvania, George E. Thomas, with Patricia Likos Ricci, Richard J. Webster, Lawrence M. Newman, Robert Janosov, and Bruce Thomas. Charlottesville: University of Virginia Press, 2012, 331-333.

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