What is cast iron? Cast iron is an alloy of iron and carbon manufactured by roasting iron ore in a blast furnace.
During the purification process the metal is liquefied and poured into non-metallic casting beds with capillaries, or ingots, which are referred to as pigs. (The shape of the receptacle looks like a sow with suckling piglets.) The pigs are then re-smelted to produce cast iron.
Cast iron was a much cheaper option than wrought iron and much more malleable. It also had load bearing strength but in contradiction, it was more brittle. In the early days of cast iron production, impurities were difficult to eradicate, and this affected the strength of the material. This is probably one reason why some cast iron drinking fountains fared much better than others.
When in contact with water and oxygen iron transforms into a compound called iron oxide – what we know as rust. It is a chemical reaction. Drops of water combine with carbon dioxide and create an acid which dissolves the iron.
It seems strange that a metal prone to rusting would be chosen to manufacture drinking fountains when these structures were intended to be placed outdoors in an oxygen rich environment with the purpose of providing drinking water. However, because it was reasonably cheap to manufacture it became very popular especially during the Victorian Era.