Flint and steel mill, predecessor of safety lamps. Invented in the early 17th century at Newcastle-upon-tyne by Carlisle (also: Carlyle or Charles) Spedding (*1696, †1755). By turning the handle the steel wheel will rotate fast. The operator pressed a flintstone against the wheel, resulting in a huge spark fountain. It was believed in that time that the temperatur of the sparks was so low, they couldn't ignite possible firedamp. This was, however, not true. German mining museum, Bochum, Northrhine-Westfalia, Germany.
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