Safety lamp principle, historical artwork. The flame from the bunsen burner does not extend beyond the metal gauze placed above it. This is the principle behind the safety lamp developed by English chemist Humphry Davy (1778-1829) to shield naked flames in lamps and prevent them igniting flammable gases in mines. Artwork from the third edition of 'Les Entrailles de la Terre' (1902) by French author Eugene Caustier.