What is the difference between cast iron and wrought iron?Iron is a soft, natural element in our environment. Elements like carbon can be added to iron to create other compounds, including steel. The properties and uses of iron change as different element proportions are combined with various heat intensities.
Wrought iron has a low carbon content, which makes it pliable when heated in a forge—it is easily "wrought" or worked on by a hammer to shape it. A type of wrought iron called puddled iron was used to construct the Eiffel Tower. Cast iron, on the other hand, has a higher carbon content, which allows it to liquify at high temperatures. The liquid iron can be "cast" or poured into a prefabricated mold. When the cast iron is cooled, it hardens. The mold is removed, and the cast iron has taken the shape of the mold. Molds can be reused, so cast iron building modules can also be mass produced, unlike 19th century hammered wrought iron.
- The National Trust of Australia owns three Portable Iron Houses, imported from England in the 19th century, and open to the public
- The neoclassical dome of the US Capitol
- Ladd & Bush Bank, Salem, Oregon
- E.V. Haughwout Store, 488 Broadway, NYC
- Kitchen, Montross & Wilcox Dry Goods Store, 85 Leonard Street, NYC
- John Roebling used both cast iron and wrought iron for suspension bridge construction
- The Maintenance and Repair of Architectural Cast Iron by John G. Waite, AIA, Preservation Brief 27, National Park Service, U.S. Department of the Interior
- Cast-Iron Architecture, Gallery of Images
- A Short History of Steel: The Era of Iron
Books About Cast-Iron Architecture:
- Cast-Iron Architecture in America: The Significance of James Bogardus by Carol Gayle (1998)
- Cast Iron and the Crescent City by Ann Masson and Lydia Schmalz (2011)
- Badger's Illustrated Catalogue of Cast-Iron Architecture, 1865 (Dover Publications, 1982)
Public Domain version online at the Internet Library
- Cast-Iron Architecture in New York: A Photographic Survey by Margot Gayle and Edmund V. Gillon (1974)
What Others Say About Cast-Iron Architecture:
"But I believe no cause to have been more active in the degradation of our natural feeling for beauty, than the constant use of cast iron ornaments. The common iron work of the middle ages was as simple as it was effective, composed of leafage cut flat out of sheet iron, and twisted at the workman's will. No ornaments, on the contrary, are so cold, clumsy, and vulgar, so essentially incapable of a fine line, or shadow, as those of cast iron; and while, on the score of truth, we can hardly allege anything against them, since they are always distinguishable, at a glance, from wrought and hammered work, and stand only for what they are, yet I feel very strongly that there is no hope of the progress of the arts of any nation which indulges in these vulgar and cheap substitutes for real decoration. Their inefficiency and paltriness I shall endeavor to show more conclusively in another place, enforcing only, at present, the general conclusion that, if even honest or allowable, they are things in which we can never take just pride or pleasure, and must never be employed in any place wherein they might either themselves obtain the credit of being other and better than they are, or be associated with the downright work to which it would be a disgrace to be found in their company."—John Ruskin, The Seven Lamps of Architecture, 1849, pp. 58–59
"The spread of prefabricated iron fronts imitating masonry buildings quickly aroused criticism in the architectural profession. Architectural journals condemned the practice, and various debates were held on the subject, including one sponsored by the recently founded American Institute of Architects."—Gale Harris, Landmarks Preservation Commission Report, p. 6, March 12, 1985 (PDF).
"[The Haughwout Building,] a single pattern of classical elements, repeated over five floors, yields a facade of extraordinary richness and harmony...[The architect, J.P. Gaynor] invented nothing. It is all in how he put the pieces together...like a good plaid....A building lost is never regained."—Paul Goldberger, Why Architecture Matters, 2009, pp. 101, 102, 210.