The Bessemer Blast

In 1856, Henry Bessemer stood before the British Association for the Advancement of Science in Cheltenham, England, and announced something that sounded impossible. He could transform brittle, impure iron into strong steel — not through slow, painstaking labor, but by blasting it with fire. His Bessemer converter was terrifying to watch. Workers poured molten pig iron into a massive pear-shaped vessel, then forced air through the bottom at tremendous pressure.…