Geordie lamp the base so that it gave more light and tried new versions on 4 and 30 November. This was presented to the Literary and Philosophical Society (Lit & Phil) of Newcastle upon Tyne on 5 December 1815. Although controversy arose between Stephenson's design and the Davy lamp (invented by Humphry Davy in the same year), Stephenson's original design worked on significantly different principles from Davy's final design. If the lamp were sealed except for a restricted air ingress (and a suitably sized chimney) then the presence of dangerous amounts of firedamp in the incoming air would (by its combustion) reduce
Safety lamp can impinge on the gauze. The shield had the disadvantage of not allowing the collier or the deputy to check that the gauze was in place and clean. Lamps were therefore made so that they could be inspected and then the bonnet placed on and locked. In the Davy lamp a standard oil lamp is surrounded by fine wire gauze, the top being closed by a double layer of gauze. If firedamp is drawn into the flame it will burn more brightly and if the proportions are correct may even detonate. The flame on reaching the gauze fails to pass