Sudanese iron spear, 1930s.
© Science Museum / Science & Society Picture Library
This barbed iron spear was made and used by the Jur people of Sudan, and although it is only about 60 years old, the methods used to produce it date back over 2000 years. Iron's high melting point meant that extracting the metal from its ores was a difficult proces. The material had to be heated to red-hot temperature, and constantly refined to expel impurities. Carbon, in the form of charcoal, was then added to improve the metal's qualities. The end result in this case was a barbed spear, that was easy to sharpen and has a lethal cutting edge.