The hot blast technique, in which the hot flue gas from a blast furnace is used to preheat combustion air blown into a blast furnace, was invented and patented by James Beaumont Neilson in 1828 at Wilsontown Ironworks in Scotland. Hot blast was the single most important advance in fuel efficiency of the blast furnace as it greatly reduced the fuel consumption for making pig iron, and was one of the most important technologies developed during the Industrial Revolution. Falling costs for producing wrought iron coincided with the emergence of the railway in the 1830s.