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
Moderator lamp Moderator lamp The moderator lamp is a type of 19th century oil lamp. It displaced the more complex Carcel lamp which used a clockwork pump. Its mechanism was simpler and required less maintenance or repair. The moderator lamp was invented in 1837 by Charles-Louis-Félix Franchot (1809-1881) . Like the Carcel lamp the oil reservoir was below the burner and it allowed 360 degree illumination. Earlier oil lamps such as the Argand had a reservoir above the burner which made them top heavy and obscured some of the light. The reliability of the mechanism led to them being adopted in lighthouses.