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 ensure that the wick was lowered and the lamp extinguished by any attempt to open it. The lamp was "much more expensive than the forms of lamp now in general use, but Mr, Yates states that the saving of oil effected by its use will in one year pay the additional cost". The Evan–Thomas lamp is similar to a shielded Clanny, but there is a brass cylinder outside the gauze above the glass. It resists draughts well but the flame is dull. The Morgan is a cross between the Mueseler and the Marsaut. It is a shielded lamp with a