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 However, by 1910 there were only 2055 electric lamps of all types in use - about 0.25% of all safety lamps. In 1911, an anonymous colliery owner, through the British government, offered a prize of £1000 () for the best lamp to specified requirements. There were 195 entries. It was won by a German engineer with the CEAG lamp, which was hand-held and delivered twice the illumination of oil lamps, with a battery life of 16 hours. Awards were made to 8 other lamps that met the judges' criteria. Clearly this stimulated development and over the next few years there