Bessemer Process

Henry Bessemer, Britain, patent of 1856. Blowing air through molten iron made cheap steel.

Overview

Bessemer patented the converter that blasted air through molten pig iron, burning impurities and making steel cheaply at scale. William Kelly in America independently patented similar work; cross-licensing settled it. Cheap steel built rails, bridges, and the first skyscraper frames. The 1856 announcement at Cheltenham let rivals race ahead until Bessemer recovered metallurgical control with collaborator Goran Goransson. Steel output multiplied a hundredfold in decades. Modern cities are steel cities because of this patent.