Mueseler type miner's lamp made by William Edward Teale in Manchester between 1871 and 1912. The lamp's regulated air current and protective 'bonnet', allowed it to burn more brightly and safely than the un-shielded Clanny and Davy lamps that had come before it. It was considered safe in explosive currents of up to 15 feet per second.
The Belgian Mueseler type flame safety lamp takes air for combustion through holes in the lamp's 'bonnet' or shield. The air then passes through an internal gauze to the flame and out again through an internal chimney.
Flame safety lamps had two main functions. Firstly, they gave safe light in a dangerous atmosphere, and secondly, they indicated the presence of methane through changes in their flame's colour. Flame safety lamps began to be replaced by safer electric lamps at the beginning of the 20th century, although they remained in use as the easiest and most reliable gas indicators well into the middle of the century.