Stephenson�s and Davy�s safety lamps, c 1815.

UNITED KINGDOM - SEPTEMBER 04: Engraving by J Pass. Miners worked by the light of naked flames during the 18th century, but these could ignite 'firedamp'. George Stephenson's (1781-1848) safety lamp was covered by a glass chimney, surrounded by an outer casing and a top of wire gauze. The Davy lamp, invented in 1815 by British chemist Humphry Davy (1778-1829), was the first miners' safety lamp. Each lamp consisted of a cylinder of wire gauze containing a wick attached to an oil reservoir and surrounded by an iron frame. However, despite many modifications and improvements to its design, the Davy lamp did not succeed in reducing the number of accidents or fatalities. Illustration from 'Encyclopaedia Londinensis, or, Universal Dictionary of Arts, Sciences, and Literature' published in London, 1810-1829. (Photo by SSPL/Getty Images)