History of chemistry iodine first, but both scientists acknowledged Courtois as the first to isolate the element. In 1815, Humphry Davy invented the Davy lamp, which allowed miners within coal mines to work safely in the presence of flammable gases. There had been many mining explosions caused by firedamp or methane often ignited by open flames of the lamps then used by miners. Davy conceived of using an iron gauze to enclose a lamp's flame, and so prevent the methane burning inside the lamp from passing out to the general atmosphere. Although the idea of the safety lamp had already been demonstrated by
Safety lamp the ancestor of all modern oil safety lamps. George Stephenson came from a mining family and by 1804 had secured the post of brakesman at Killingworth colliery. He was present at both the 1806 and 1809 explosions in the pit. By 1810, he was engineman and responsible for machinery both above and below ground. The pit was a gassy pit and Stephenson took the lead in work to extinguish a fire in 1814. For some years prior to 1815 he had been experimenting on the "blowers" or fissures from which gas erupted. He reasoned that a lamp in a chimney