Safety lamps, early 19th century.
© Science Museum / Science & Society Picture Library
Diagrams of safety lamps designed by George Stephenson (1781-1848), Sir Humphry Davy (1778-1829), Clover & Cail and T Y Hall. Until the invention of the safety lamp, miners worked by the light of candles or other naked flames but these could ignite 'firedamp', a gas found in deep mines. Illustration from 'A practical treatise on mine engineering' by , George Clementson Greenwell (1821-1900), published in 1869.