Page 29 - Curriculum Visions Dynamic Book

 An 18th-century iron foundry.
Types of cast iron
Cast iron varies according to its silicon and carbon content. Grey cast iron is the most common. It is easily cast and machined,
and is used for casting vehicle engine blocks.
To change the properties of grey cast
iron into other forms, it must be remelted and the chemical composition altered. Alternatively, some changes can be produced by controlling the rate at which the iron cools after casting.
The uses of cast iron
Cast iron was first introduced as a structural material in the late 18th century. The first buildings to benefit from this new material were factories, where heavy machinery could now be supported on cast iron columns. Warehouses were also quick to use and display this new material.
The idea of supporting a building with cast iron frames was of vital importance to modern society because it led to the development of high rise (skyscraper) frame construction in the 20th century. But some of the most flamboyant uses of the metal were in combination with glass panels to make intricately patterned windows. These were used for railway stations and great exhibition halls such as London’s Crystal Palace (built 1851).
For many centuries, ironmakers had made intricate metal objects by working wrought iron with great skill. The mass production of cast iron decorative ware allowed much cheaper production. Eventually the skills of many of these ironworkers were lost.
 In the 19th century it became very fashionable to use cast iron as
a decorative part of architecture. Many railway stations and other large public buildings show an enormous range of uses for cast iron. However, it was used to great effect in many domestic buildings as well. One of the world’s most famous uses of
cast iron in buildings is seen on these Sydney houses, where exquisitely produced cast iron decorates many of the townhouses of the period. The cast iron is protected from weathering by paint.
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