The ‘safety lamp’ invented by Humphrey Davy in 1815 utilised the cooling effect of metal gauze to
prevent the flame of a candle or oil lamp (essential for illumination in mines) from passing through
such a screen. It is therefore rendered unable to ignite any potentially explosive mixture of air
and methane in the atmosphere surrounding the lamp. A number of experimental demonstrations are
detailed to illustrate this effect, and show how the lamp could also indicate the presence of
methane in the air of a coal mine.