Safety lamp could create a sufficient updraft that firedamp would not penetrate down the chimney. Further observations of the speed of flame fronts in fissures and passageways led him to design a lamp with fine tubes admitting the air. Sir Humphry Davy was asked to consider the problems of a safety lamp following the Felling explosion. Previous experimenters had used coal gas (chiefly carbon monoxide) incorrectly, believing it to be the same as firedamp. Davy however performed his experiments with samples of firedamp collected from pits. As an experimental chemist, he was familiar with flames not passing through gauze; his experiments enabled
Safety lamp the Stephenson lamp was easily broken, and allowed the flame to ignite firedamp in the mine. Later Stephenson designs also incorporated a gauze screen as a protection against glass breakage. Developments, including the Gray, Mueseler and Marsaut lamps, tried to overcome these problems by using multiple gauze cylinders, but glass remained a problem until toughened glass became available. Were the flame to go out in a lamp, then there was a temptation for the collier to relight it. Some opened the lamps to light tobacco pipes underground. Both of these practices were strictly forbidden; they clearly negated the whole point