24. Ancient Scandinavians Stumbled Upon Steel Because of Superstition
Ancient Scandinavians’ only available iron was bog iron – an impure and soft metal. That put them at a disadvantage against neighbors armed and armored with better iron. However, Scandinavian religious beliefs led them, unwittingly, to forge an early version of steel swords. That gave them a literal edge over their opponents. Scandinavians believed that if they mixed the bones of killed animals with the iron used to forge swords, the resultant weapon would be imbued with the spirit – and strength – of the killed animal. That was superstitious mumbo jumbo, but the swords that emerged were pretty strong, nonetheless. The cause was not spirituality, but science.
Sacrificial bones combined with iron did not give swords spiritual powers. However, what Scandinavian smiths did not realize was that the bones, like any organic matter, contained carbon. Carbon mixed with iron produces a rudimentary form of steel. When they burned coal alongside their low quality bog iron, Scandinavian smiths unwittingly produced bone coal – similar to how burning wood produces charcoal. When modern researchers conducted experiments and mixed bone coal with bog iron to forge swords, they discovered that the process significantly improved the sword. Carbon from the bones penetrated up to three millimeters deep into the bog iron, and produced a significantly stronger weapon.