Bessemer invented a steel making process which revolutionised structural engineering and established Sheffield as a major industrial centre. He had been trying to reduce the cost of steel, when he developed his system for blowing oxygen through pig-iron to remove the impurities. This made steel easier and quicker to manufacture. Bessemer also made over 100 other inventions in the fields of iron, steel and glass, including: movable dies for embossed postage stamps; and a screw extruder to extract sugar from sugar cane. He was knighted for his contribution to science on 26 June 1879, and in the same year was made a fellow of the Royal Society.