Before revision: History 150px|Drop-bottom cupola furnace Cupola furnaces were built in China as early as the Warring States period (403–221 BC), although Donald Wagner writes that some iron ore melted in the blast furnace may have been cast directly into molds.
After revision: Personal protective equipment to shield from radiant heat and molten splashesHistory 150px|Drop-bottom cupola furnace Cupola furnaces were built in China as early as the Warring States period (403–221 BC), although Donald Wagner writes that some iron ore melted in the blast furnace may have been cast directly into molds.